Development of rubberized concrete with mineral admixtures for sustainable concrete

Development of rubberized concrete with mineral admixtures for sustainable concrete | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Development of rubberized concrete with mineral admixtures for sustainable concrete Freddy Joans Marboh, Narasimha Murthy K N This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6264503/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract With the increasing demand for concrete, there are environmental concerns relating to the dwindling natural aggregates and high carbon footprint produced due to the cement industry. Current research, therefore, aims to determine if rubberized concretes can be made sustainable by ‘partial replacement of fine aggregates with waste’ rubber along with 20% GGBS and 10% metakaolin for partial replacement of Portland cement. The experimental program intended to study the fresh and hardened properties, namely, slump, density, ‘compressive strength,’ split tensile strength,’ flexural strength,’ microstructural and spectroscopic properties (SEM and FTIR). The results showed that slump decreases by 18.37% and density by 7.5% at 10% rubber replacement. While compressive strength improved by 8.8% with the addition of mineral admixtures and declined by 30.5% when 10% rubber was added. Likewise, split tensile and flexural strengths at 0% rubber showed improvements of 2.8% and 8.25%, respectively, while at 10% rubber showed reduction of 38.1% and 18.75%, respectively. In spite of these decrements in strength, microstructural analysis demonstrated that the GGBS and metakaolin enhanced the hydration process and densified the matrix, which mitigated strength losses. Thus, an optimum sustainability-structural balance was noted at 2.5% rubber replacement, thereby rendering rubberized concrete a promising eco-friendly alternative for construction uses. Rubberized concrete Mineral admixtures Waste rubber Sustainable concrete Scanning Electron Microscopy (SEM) Fourier Transform Infrared Spectroscopy (FTIR) Analysis Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 Figure 15 1. INTRODUCTION Concrete, then, is acknowledged to be’the most widely’’consumed construction material on the planet because of its fascinating strength, durability, and adaptability. It remains to form a considerable part in the construction of buildings, roads, bridges, etc., the list goes on, and hence why the substance is crucial in the contemporary infrastructure development that lies beneath urbanization and economy [ 1 ]. Concrete is an irreplaceable material for ‘the construction industry’owing to its great compressive strength, fire-resistance ability, and long service life [ 2 ]. However, because of these increasing demands for concrete, many environmental concerns grew. Cement, an important binder for concrete, produces nearly 8% of global anthropogenic CO₂ emissions [ 5 ]. Furthermore, environmental deterioration, including habitat damage and river bed depletion, has been brought on by the extraction of natural resources such river sand for fine aggregates [ 4 ]. Researchers are now looking on sustainable substitutes for traditional concrete ingredients that can preserve or improve performance as a result of these difficulties [ 8 ]. While the concrete industry has enjoyed reliable properties and multipurpose applications, it also presents serious problems regarding resources and the environment. The over-extraction of natural fine aggregates or river sand, poses an obstacle to sustainable construction methods by leading to habitat destruction, erosion, and river bed depletion [ 4 ], [ 16 ]. Calcining limestone and burning fossil fuels account for nearly 8% of world CO₂ emissions; hence, cement sector is one of the major sources of CO₂ emissions [ 5 ], [ 11 ]. Water is also used in very high amounts, causing further depletion of resources [ 8 ]. Environmental issues of sorts have become more and more an issue of sorts with an estimated 1.5 billion tires being disposed annually in some way or the other [ 1 ]. Most of these tires are taken stock of, or landfilled illegally dumped. This causes severe environmental problems. Tires are tough and non-biodegradable. They would take hundreds of years to decompose while in a landfill, thus occupying precious areas of the latter [ 20 ]. Also, such as the nature of conveniently disposed tires that they often form large heaps which become incredibly difficult to extinguish at fire time. As a result, harmful smoke is released, contaminating the air and negatively affecting nearby communities [ 4 ], [ 5 ], [ 22 ]. On the basis of waste tires, the hazardous chemicals like oils and carbon black can seep into the groundwater and soil, causing chronic contamination that interferes with ecosystem processes and poses a serious threat to human health [ 8 ], [ 20 ]. In addition, inappropriate disposal of waste tires amount to the loss or repurposing of valuable raw materials that can be recycled or reused: rubber, steel and carbon black thus considered an enormous waste of materials [ 11 ], [ 21 ]. The ecological and resource-related plights must pose greater prospects for sustainable development in waste tire management [ 26 ], [ 28 ], [ 29 ]. Rubber particles substitute conventional fine aggregates such as sand and thus reduce the demand for natural resources and landfill space [ 4 ], [ 8 ]. On the other hand, recycling rubber minimizes fire hazards and toxic emissions from stockpiled tires and also bolsters the circular economy [ 5 ], [ 11 ], [ 21 ]. Rubberized concrete has increased resistance to impact, flexibility, and thermal insulation, making it appropriate for use in pavements and noise barriers [ 17 ], [ 29 ]. Though it tends to lower compressive strength, various researchers are studying mix designs and some additives like GGBS and fibers to achieve higher strength [ 8 ], [ 28 ]. This approach also has a definite advantage in terms of sustainability as by minimizing waste, conserving resources, and completing the cycle in the circular economy [ 5 ], [ 21 ], [ 30 ]. ‘The use of waste rubber as a partial substitute for fine aggregates in concrete’ presents a number of mechanical in nature, durability, and workability issues. Because rubber is softer than natural aggregates, it creates weak spots in the ‘concrete matrix, which lowers the concrete's tensile and ‘compressive strength’[ 12 ], [ 18 ]. Besides, the rubberized concrete tends to have more air contents, less density, and different water-cement interactivity, which usually calls for adjustments for mix proportioning or the addition of plasticizers [ 4 ], [ 20 ]. Issues arising from water absorption and shrinkage call for durability concerns that can very well be treated with surface treatments and optimized mix designs [ 11 ], [ 21 ]. Adding more cementitious ingredients to concrete has the potential to improve "its strength and overall performance characteristics.’For example, metakaolin and GGBS have been proven to be beneficial for rubberized concrete mixes [ 8 ], [ 28 ], [ 32 ] thus creating an avenue for sustainable exploitation in construction applications. Very limited studies were conducted on the combined application of waste rubber as fine aggregate and mineral admixtures like GGBS and Metakaolin to counter the weaknesses of rubberized concrete. Although studies have investigated independently the merits of GGBS and Metakaolin in terms of advancing the concrete strength and durability [ 15 ], [ 16 ] [ 19 ], [ 27 ], not so much has been paid attention to finding their synergistic effects with the rubber particles. Their combined potential to reverse that scenario discovered in rubberized concrete by having the activities of countering the opposing effects of loss of compressive strength thereby improving bonding and refining the microstructure need to be examined further [ 8 ], [ 18 ]. 2. LITERATURE REVIEW Waste tire rubber incorporation in concrete is an area of extensive investigation by researchers seeking to evaluate this material's potencies’as a sustainable alternative to conventional aggregates.’’The comprehensive‘use of waste tire rubber in cement concrete,’ cited in several literatures for its promising effects of reducing environmental pollution and enhancing thermal and acoustic insulation properties for concrete. However, they cited limited work done in the reduction in mechanical strength, an issue that reappears time and again in other studies that followed by [ 1 ], [ 2 ] examined a high-strength concrete's "mechanical and dynamic" characteristics using "well-graded coarse and fine tire rubber." According to their findings, adding rubber particles to the concrete decreased its "compressive strength" while increasing its ductility and energy-absorbing ability. Thus, this type of high-strength concrete can be used for impact-resistant applications. The good thing about using pervious concrete in stormwater management with an insight into its low flexural strength. To enhance structural performance, reinforcement with geogrid has been studied by [ 3 ]: it improves load-bearing capacity and ductility. Following this, the study experimentally investigates ‘the outcome of layers of geogrid on the flexural behaviour of pervious concrete beams.’Research on the mechanical attributes of rubberized concrete is relatively popular. Mechanical as well as durability properties were investigated in concrete that used recycled rubber ash and fibers by [ 4 ], they concluded that rubber ash and fibers contribute to flexural strength and toughness in concrete, although a slight ‘decrease in compressive strength’ was noted. On the other hand, [ 5 ] researched green selection ‘of concrete with recycled tire aggregate’for structural applications from medium to low strength and concluded that rubberized concrete could indeed be possibly non-structural applications for which high strength is not an overall requirement. Experimental studies were also conducted by [ 6 ], which involved use of waste shredded tire rubber as substitute for fine aggregate in concrete. Results indicated lower compressive strength when the amount of rubber is increased in concrete mixes, yet showed improved impact resistance as well as ductility. This was supported by [ 7 ], who assessed the properties of using crumb rubber in concrete to partially substitute coarse aggregate; the inclusion of crumb rubber improved the energy absorption of the concrete. Hence, it became suitable for use in pavements and structures that require shock absorption. Several investigations have been conducted concerning ‘the mechanical properties of rubberized concrete.’ Mechanical and durable properties of concrete containing recycled rubber ash and fibers studied by’[ 8 ], they concluded that with the addition of rubber ash and fibers, the bronchial strength and toughness were enhanced, although a little reduction is also observed in compressive strength. In another study, [ 5 ] analyzed the sustainable selection of using recycled tire aggregate within concrete to serve medium and low strength applications, admitting that rubberized concrete was possible ‘for non-structural applications that did not require high strength.’ The experimentally was proved by [ 6 ], that leftover shredded rubber tires are used ‘in place of fine aggregate in concrete.’ The findings show that while‘’the compressive strength declined as’the percentage’ of rubber increased, concrete's ductility and impact resistance improved. This was further supported by [ 7 ], who studied crumb rubber as a partial ‘replacement for coarse aggregate in concrete.’’The presence of crumb rubber also enhanced energy absorption capacity of the concrete, making it applicable in use for pavements and shock-absorbing structures. Additional investigations have been continued in order to evaluate the durability aspect of rubberized concrete where, [ 8 ] revealed the results of a study on the effects of waste glass powder and silica fumes in crumb rubber cement, where the crumb rubber was used to partially substitute fine aggregates. They came to the conclusion that waste glass powder and silica fumes enhance the mechanical qualities and longevity of rubberized concrete, mitigating some of the negative impacts of rubber on strength. In a recent paper, [ 9 ] examined how the mechanical characteristics of rubberized concrete were affected by the pre-treatment of rubber fibers. According to their findings, pre-treating rubber fibers strengthened the cement matrix's bond with rubber, improving the material's mechanical qualities and [ 10 ]’investigated the impact of the addition of polypropylene fibers on the mechanical and lasting properties’of’ rubber tire fine aggregate concrete, coming to the conclusion that adding polypropylene fibers improves the concrete's tensile strength and durability, increasing its resistance to environmental deterioration and cracking Many studies have been conducted on blending utilized the supplementary cementitious ‘materials to enhance the concrete performance.’The study results of [ 12 ] indicated that high strength concrete has a better performance with the use of metakaolin and ‘GGBS’with regard to compressive strength and durability. Mechanical and microstructural properties of concrete studied by [ 13 ] and [ 14 ] analyzed the influence of rubber waste particle sizes and dosages on mechanical properties of rubberized concrete composite and found that with small rubber particles, low dosages would better improve the mechanical properties, especially when used with supplementary cementitious materials. Now, the microstructure of rubberized concrete is one of the main research areas where, [ 15 ]‘studied the ‘Mechanical and microstructural properties of a quaternary binder system with OPC, GGBS, metakaolin, and lime.’ It was concluded that the incorporation of metakaolin and GGBS enhanced the microstructural properties of concrete, hence improving its mechanical properties and then [ 16 ] studied the’fresh and hardened properties of self-compacting ‘concrete using metakaolin and GGBS as cement’ conversions. ’They reported that the use of these materials increased the workability and strength of the concrete, especially in view of its wide field of applications. The various studies have also emphasized on the environmental and economic advantages of using waste tire rubber in concrete construction. Giving a full review of performance in using waste rubber tires in concrete, [ 21 ] mentioned the opportunity to reduce landfill waste and‘lower the carbon footprint of concrete production,’[ 22 ] ‘evaluated the’mechanical and durability properties of concrete’with’rubber waste tires as fine aggregate’and noted that the incorporation of rubber into concrete will lead to sustainable construction practices while maintaining acceptable performance levels. Most of the innovation-oriented work in rubberized concrete has now been completed. Research of [ 28 ] demonstrates that rubber powder from discarded tires has improved properties for foam concrete making it more thermally and acoustically effective. The authors [ 29 ], revealed that in their ‘mechanical and microstructural analysis of sustainable concrete, using recycled concrete with waste rubber’tire fibers holds a bright potential for structural applications of rubberized concrete. Experimental study was performed by [ 30 ] on rubberized concrete for containing the highest rubber content, examining mechanical properties. The study showed that increased rubber content would have a significant impact on both compressive and tensile strengths, with reduction, which is a result of the lower stiffness of rubber compared to conventional aggregate. However, improvements were found in energy absorption and impact resistance, making rubberized concrete a candidate for applications where high toughness is required and [ 31 ] also studied the ‘combined effect of lightweight fine aggregate and micro rubber ash on properties of cement mortar.’ The study findings showed that micro rubber ash inclusion enhanced the morphology and durability of cement mortar, eventually reducing density, and indicated the potential use of such materials for green and lightweight construction. Another study was conducted by [ 32 ], which argued about the nature of ‘performance of rubber aggregate concrete modified with GGBS and silica.’ 3. ‘MATERIALS’ 3.1 ‘Cement’ ‘Ordinary Portland Cement of 53 Grade is used’as per IS 4031:1988 [ 33 ]. Specific gravity by the Le Chatelier flask method is 3.11. The consistency of cement was determined to be 34%.‘Initial setting time and final setting time’ by Vicat apparatus were recorded as 80 and 320 minutes, respectively. Cement fineness was determined with 8% retained on a 90-micron sieve. Dark grey colour was observed in the cement. ‘The chemical composition is shown in Table 1 .’ Table 1 ‘Chemical composition of Ordinary Portland Cement (OPC 53) and mineral admixtures’ Chemical Name Cement Mass (%) GGBS Mass (%) Metakaolin Mass (%) Silica (SiO₂) 21.25 34.81 70.4 Alumina (Al₂O₃) 4.33 17.92 21.85 Ferric Oxide (Fe₂O₃) 1.85 0.66 0.38 Titanium Oxide (TiO₂) 0.13 - - Calcium Oxide (CaO) 64.3 37.63 0.17 Magnesium Oxide (MgO) 1.81 7.8 1.47 Sodium Oxide (Na₂O) 0.17 - 3.47 Potassium Oxide (K₂O) 0.71 - 0.63 Loss On Ignition (LOI) 1.5 -0.35 - Manganese Oxide (MnO) - 0.21 - Chlorine (Cl) - 0.004 - Insoluble Residue (IR) - 0.19 - Sulfur Trioxide (SO₃) - 0.2 0.58 Sulphide Sulphur - 0.51 - Phosphorus Pentoxide (P₂O₅) - - 0.63 Titanium Dioxide (TiO₂) - - 0.02 Vanadium Pentoxide (V₂O₅) - - 0.02 Strontium Oxide (SrO) - - 0.01 ‘Note : OPC: Ordinary Portland Cement, GGBS: Ground Granulated Blast Furnace Slag’ 3.2 ‘Fine Aggregates’ ‘M-sand used in the present study as a fine aggregate conforming to IS 2386:1963’ [ 34 ]. According to standard grading specifications, going through a 4.75 mm sieve qualified the M-sand into Zone II grading. The characterization of fine aggregate gave specific gravity equal to 2.47 giving the density in respect to water, while the fineness modulus is identified as 2.85, giving it the attribute of being coarse. Particle size distribution, as shown in Fig. 1, gives overall insight into the gradation and suitability of the fine aggregate for the concrete mix. 2.3 ‘Coarse Aggregates’ ‘The coarse aggregate employed in this investigation was material maintained on a 4.75 mm screen with a maximum particle size of 20 mm, in accordance with IS 2386:1963’ [ 34 ] and IS 383:2016 [ 39 ] standards. The physical parameters of the coarse aggregate were carefully investigated, revealing a specific gravity of 2.66, which shows its density in relation to water. Furthermore, the fineness modulus was estimated as 7.45, demonstrating the aggregate's gradation and particle size dispersion. The water absorption rate was determined at 0.75%, indicating that the material can retain moisture. Figure 1 depicts the coarse aggregate's detailed particle size distribution, which provides more insight into its appropriateness for use in concrete manufacturing. 2.4 materials Additive 2.4.1 Waste rubber According to ASTM D854 [ 38 ], ‘waste rubber (WR), having a specific gravity of 1.2 and a particle size of 40 mesh or 0.425 mm, water absorption and moisture content was observed to be’ 0.77% and 0.82% which was tested as per the ASTM D1509 [ 40 ] guidelines, it was procured from a well-known supplier based in the Peenya Industrial Area, Bangalore. This waste rubber was selected for ‘partial replacement of fine aggregates in concrete,’ with carefully chosen replacement levels of 2.5%, 5%, 7.5%, and 10% by volume. As can be seen in Fig. 2 (a), the waste rubber appears black in colour, indicating that it is in processed form. Before the WR was introduced into the concrete mixing, it was cleaned properly as shown in Fig. 2(b) where every particle was washed with clean water to ensure that no dirt or impurities could possibly remain. Then the rubber particles were laid to dry for 24 hours in order to make certain that they were free of moisture, which is required for a good mixing of WR with the other constituents of concrete. Whereas Fig. 2(c) as ‘it can be seen from the SEM image shown,’ the WR has an irregular in shape and some of the sharp edges present. It enhances the interlocking but due to irregular in shape it may present voids around the corners, the particles' shape makes it simple to trap air around them. 2.4.2 ‘Ground Granulated Blast Furnace Slag (GGBS)’ ‘The physical characteristics of the GGBS utilized in this investigation are shown in Table 2 .’ and it meets the requirements for concrete applications as stated in BS 6699 [ 41 ]. GGBS was frequently used at a predetermined amount of 20% as a ‘partial cement replacement to enhance the properties of concrete.’ Table 1 displays the chemical makeup. As shown In Fig. 3 this SEM image of GGBS at 5000× magnification reveals angular, fractured, and irregular particles with smooth and rough textures, enhancing reactivity in concrete. The layered or striated surfaces suggest internal fracturing, improving cement hydration. Fine debris indicates mechanical grinding effects. The 10 µm scale bar demonstrates its ultra-fineness captured by an ETD detector at 10.00 kV. These characteristics help to bond more thoroughly and facilitate‘the formation of more C-S-H gel,’ leading to improved ‘strength and durability of concrete.’ 2.4.3 Metakaolin (MK) To ensure its quality and uniformity, the metakaolin used in this investigation was manufactured in accordance with IS 4031: 1988 [ 33 ]. Table 2 displays the physical characteristics, whereas Table 1 displays the chemical composition. ‘In order to improve some of the mechanical and durability features of concrete,’ a constant percentage of 10% was added to the mix by partially substituting cement with metakaolin. By lowering the need for traditional cement, this continuous replacement would not only enhance the overall performance of concrete but also guarantee environmentally friendly and sustainable practices in the building sector. The SEM image as shown in Fig. 4 of metakaolin shows the heterogeneous, angular, plate-like particles with significant aggregation at a 5000× view, suggestive of a large surface area and pozzolanic activity. Through increased reactivity with cement hydrates, this roughness enhances mechanical characteristics. These fine powders, size ranges submicron to micrometre, enable metakaolin to ‘fill the voids within the cement matrix and react with calcium hydroxide to increase both compressive and flexural strengths of the resulting cement.’ Table 2 Physical Properties of GGBS and Metakaolin Property GGBS Metakaolin Physical State Powder Micronized Powder Odour Odourless Odourless Color Light Grey white pH (10% solids) 10–12 4.5–5.5 Bulk Density (kg/m³) 1000–1200 400–500 Specific Surface Area (m²/g) 400–600 19–20 Specific Gravity 2.9 2.4 Water Absorption (g/100g) Negligible Fineness (m²/kg) 275 (Min) 441 Loss on Ignition (%) < 3.0 0.33 Glass Content (%) High (70%+) - MK Content (%) - 97.0% MIN Reactive with Lime (MgCa(OH)₂/gm) Moderate 1000 Reactive with Lime (MPa) Moderate - Moisture Content (%) < 0.5 0.5–1.0 Chemical Modulus (CaO + MgO + SiO₂) High (60%+) - ‘Note: GGBS: Ground Granulated Blast Furnace Slag’ 4. EXPERIMENTAL INVESTIGATION 4.1 Methodology Experimental design of M25 concrete grade was conducted. Six diverse mixes were made where by one—the control mix—remains standard concrete without the additions, while the rest mixed have supplementary cementing materials and varying amounts of waste rubber. The waste rubber was considered a partial fine aggregate replacement in proportions of 2.5%, 5%, 7.5%, and 10%. Different mechanical axial strength tests were performed on the mixes for the curing days of 7, 14, and 28 in order to assess performance. The basic objective of introducing SCMs was to enhance the concrete properties while the effects of varying proportions of rubber were studied for strength characteristics. CC means Conventional Concrete, while M10G20R0, M10G20R2.5, M10G20R5, M10G20R7.5, and M10G20R10 correspond to different mixes. In these compositions, metakaolin (M) is constant at 10% as a cement by volume replacement, while GGBS (G) is fixed at 20% by cement volume replacement, and waste rubber (R) is used to replace fine aggregate at 0%, 2.5%, 5%, 7.5%, and 10%, respectively. 4.2 Sample preparation A total of 18 samples, including cubes and cylinders, were cast for each concrete mix, namely conventional concrete (CC), and blended concrete mixes containing supplemental cementitious materials and waste rubber. The samples were designed to test the compressive and tensile strength of concrete at different curing times. In addition, 9 beam samples were cast for each mix of conventional concrete and blended concrete to determine the flexural strength. Table 3 shows the exact percentage proportions of the elements in each mix, including cement fine aggregates, metakaolin, GGBS, and waste rubber, giving a detailed view of the mix design. Table 3 Percentage replacement levels Mix Cement % Metakaolin (MK) % GGBS % Waste Rubber (WR) % Fine Aggregates (FA) % CC 100 0 0 0 100 M10G20R0 70 10 20 0 100 M10G20R2.5 70 10 20 2.5 97.5 M10G20R5 70 10 20 5 95 M10G20R7.5 70 10 20 7.5 92.5 M10G20R10 70 10 20 10 90 Note: where CC is Conventional concrete M is Metakaolin, G is GGBS and R is Waste fine rubber 4.3 ‘Mix Design’ Table 4 indicates that the concrete mix designs were M25 grade and that the respective proportions for each mix group were assigned according to the above. The design was done according to the provisions of IS 10262:2019 [ 35 ], thereby ensuring the standard requirements for quality and performance were attained by the mix. The design quantities of the various materials, namely, cement, aggregates, metakaolin, GGBS, and waste rubber, were estimated and are given in Table 4 . A uniform ‘water-cement ratio (W/C) of 0.45 was maintained’throughout all the mixes to ensure proper hydration and workability. ‘All mixes were prepared by manual mixing on a clean flat surface’with non-absorptive properties so that there would be no interference from the substrate. The dry materials, namely cement and aggregates, were first mixed homogeneously until a uniform dry blend was obtained. Water was added after the dry aggregates were uniformly mixed to arrive at a uniform concrete mixture based on each mix's calculated water content. After that, the concrete was then carefully cast into the moulds for cube, cylinder, and beam sample casting. Concrete was compacted for the filling of the moulds to eliminate any air pockets, thereby ensuring a strong structure. ‘The moulds were kept undisturbed for 24 hours so as to allow the concrete to set initially. After this duration, the moulds were very carefully removed, and the specimens were’submerged in curing water tanks for the appropriate durations in order to attain the desired strength. The curing was done based on the recommendations and guidelines to allow adequate hydration and ‘strength development of the concrete.’ Table 4 Mix proportions Mix Cement (Kg/m3) FA (Kg/m3) CA (Kg/m3) Waste rubber (Kg/m3) GGBS (Kg/m3) Metakaolin (Kg/m3) Water (Kg/m3) CC 440 640.0 1126 - - - 198 M10G20R0 308 640.0 1126 - 88 44 198 M10G20R2.5 308 624.00 1126 16.00 88 44 198 M10G20R5 308 608 1126 32.0 88 44 198 M10G20R7.5 308 592.00 1126 48.00 88 44 198 M10G20R10 308 576 1126 64 88 44 198 Note: Where Fa refers to Fine aggregate, CA refers to Coarse aggregate, CC is Conventional concrete, M is Metakaolin, G is GGBS and R is Waste fine rubber 4.4 Fresh properties of concrete Workability was determined by slump test (IS 1199:1959) [ 37 ] which measures the consistency and fluidity of concrete. The mix was then layered into a slump cone, compacted ‘with 25 strokes of a tamping rod’ per layer, the cone lifted to measure the height of the slump. High slump values signify better flowability suitable for its application in reinforced structures, where both segregation and bleeding of fresh concrete are to be avoided, whereas lower slump values indicate increased cohesion and comparatively less segregation. A bulk density equipment, which was also utilized to layer and compact the concrete in a similar manner, was employed to measure density. The compactness and strength of the mix were ascertained by calculating the bulk density, which was derived from the weight differential between the full and empty apparatus. 4.5 Hardened Properties of concrete Compressive strength, split tensile strength and flexural strength tests of hardened solid. In this process, three different Universal Testing Machine (UTM) standards (IS 516:1999) [ 36 ] were used to assess the flexural strength of beams (100 mm × 100 mm × 500 mm), split tensile strength of cylindrical specimens (150 mm diameter × 300 mm height), and compressive strength of cube samples (150 mm × 150 mm × 150 mm) respectively. The demoulding was done after 24 h and placed in a tank for curing under water for 7, 14 and 28 days. Each curing period had three specimens prepared to guarantee sound and reproducible results. The main purpose of the tests was the study of the time-dependent strength development of concrete. 5. ‘RESULTS AND DISCUSSION’ 5.1 ‘Fresh Properties of Concrete’ 5.1.1 ‘Slump Test’ Results from both literature reviews and experimental work coincidentally indicate that adding more rubber to concrete decreases its workability. Previous studies have also confirmed this trend: [ 3 ] found that slump decreased from 48 cm in a control mix to 38 cm at 25% of rubber replacement. This is in the same manner as that reported with study by [ 5 ] which showed a decline from 70 mm in ordinary concrete down to 50 mm with 20% replacement of rubber ash; similar results were reported by [ 12 ] and [ 33 ]. Untreated rubber fibers reduced slump from 100 mm to 60 mm at 20% replacement, according to [ 9 ]. However, the NaOH treatment slightly improved workability of the mixtures. This pattern was further reinforced by studies done by [ 11 ], [ 13 ], and [ 20 ]. On his side, [ 31 ] found out that lightweight rubberized mortar always maintained a steady flowability, while [ 24 ] proved that NaOH-treated rubber had better workability compared to untreated ones.‘The slump test’ shows a reduction in workability as the amount of waste latex in concrete mixtures that contain GGBS and metakaolin increases. Straightforwardly, the slump test as shown In Fig. 5 indicates that workability reduces progressively with increased waste rubber addition, as shown in previous studies. The slump for conventional concrete (CC) is 98 mm, after which a slump value of 80 mm was obtained at 10% rubber replacement, indicating a reduction of 18.37%. This reduction occurs because of the repulsion ‘of the water by the hydrophobic rubber particles’reducing fluidity. The initial mix reduced slightly to 95 mm at the first 10% metakaolin and 20% GGBS addition (M10G20R0), resulting in a 3.06% decrease due to microstructural refinement, but again increasing amounts of rubber decreased slump even more, namely: R2.5, R5, R7.5, and R10 show decreasing values of 6.12, 9.18, 14.29, 18.37 percent, respectively. The presence of metakaolin (M10) and GGBS (G20), which generally contribute to microstructure refinement and cementitious properties, were not sufficient to overcome the negative effect on workability. The trend is in line with previous studies that further confirm an adverse effect of rubber aggregates on slump. 5.1.2 Density Test Concrete's density is determined by the type shape and the specific gravity of materials present in the concrete, as per the review of density from different researcher’s state that, Rubber, in fact, replaces natural aggregates and brings about a subsequent reduction of concrete density. However, untreated rubber significantly reduces densities [ 5 ], [ 6 ] and [ 8 ] while pretreatment [ 9 ] and surface alteration [ 13 ] mitigate the effects slightly. Larger rubber particles would bring out the greater effectiveness [ 14 ]. However, to improve the density of packed material and reduce porosity offsetting density loss, GGBS, metakaolin, and polypropylene fibers were introduced [ 8 ], [ 15 ], [ 16 ]. Few studies have shown that density reduces from 2,402 kg/m³ to 2,233 kg/m³ at a 20% replacement of rubber [ 22 ] and 2,475 kg/m³ to 2,069 kg/m³ [ 21 ]. From foam concrete, rubber replacement reduced the ‘density from 1,800 kg/m³ to 1,600 kg/m³’[ 29 ]. Rubberized concrete is lightweight, but adding admixtures and surface treatments ensures optimization of its properties. Figure 6 shows the difference on density of concrete prepared with different percentages substitution with waste rubber as well as mineral admixtures. Figure 5 displays that as the percentage of waste rubber is increasing,’ the density of rubberized concrete decreased. ‘It should be noted that waste rubber has a low specific gravity’ (1.2), the Density of Conventional Concrete (CC) was observe to be 2490 kg/m 3 , whereas the addition of Metakaolin(10%) and GGBS(20%) by partial replacement to cement for concrete, the density was observed to be 2453.33 kg/m 3 , which was a slight reduction due the less specific gravity of Metakaolin (2.4) and GGBS (2.9) compared to cement(3.11).‘Whereas the partial replacement of’waste rubber to fine aggregate by volume for 2.5, 5, 7.5 and 10 percent, the results show the reduction of 3.21, 6.29, 6.56 and 7.5 percent. Reductions in density could be credited to the partial replacement of standard materials with lighter alternative materials such as an aggregate of rubber, which is lightweight certainly. 5.2 ‘Hardened properties of concrete’ 5.2.1 ‘Compressive strength test’ In general, the poor link between rubber particles and the cement matrix causes the compressive property of rubberized concrete to diminish when waste rubber is added. [ 1 – 4 ] all agree that adding more rubber lowers compressive strength. From studies, however, strength loss may be minimized through optimized mix design and incorporation of supplementary cementitious materials. [ 9 ] and [ 24 ] were able to show that pre-treatment, sort of a chemical pre-treatment, of rubber fibers with NaOH, enhances bonding leading to strength improvements. Also, research by [ 7 – 8 ] have shown that the incorporation of polypropylene fibers, silica fume, and waste glass powder improved the mechanical performance of rubberized concrete. It has also been found that the addition of metakaolin and GGBS enhances compressive strength through pozzolanic reaction and microstructure refinement [ 15 ], [ 19 ], [ 29 ]. Experiments confirm these results. ‘The compressive strength of (CC) as shown in Fig. 7 ’ was 20.04 MPa, 24.86 MPa, and 32.11 MPa at 7, 14, and 28 days, respectively. At 7 days, however, the strength of the samples in which metakaolin replaced 10% and GGBS replaced 20% of cement without waste rubber (M10G20R0) was less than that of the CC. On the contrary, this method was superior at 28 days, showing the long-term strength advantages of these mineral admixtures. As for the substitution of waste rubber fine aggregate at 2.5, 5, 7.5, and 10 percent. The findings indicated that the compressive strength gradually decreased. Nevertheless, the modified mixes gained strength over time, with the M10G20R0 mix, which contained no rubber, showing 8.8% greater strength than conventional concrete at 28 days. This is indicative of its long-term strength with the advantages of mineral admixtures. The weak link between the WR and the concrete's cement paste is the primary source of the decrease in compressive strength. The strength was less affected by small dosage of rubber percentage than the higher percentage. The trend implies that on one hand, mineral admixtures provide improvements in long-term strength, while on the other hand, an increase in rubber content makes compressive strength suffer because rubber has lesser stiffness and bonding capabilities compared to conventional fine aggregates. 5.2.2 Split Tensile Strength test There are various studies on the impacts of rubber waste‘on concrete split tensile strength,’Rubberized concrete possesses different split tensile strength depending on the type, size, percentage of rubber, and any additional materials. After‘7 days and 28 days, foam concrete with 5% rubber’powder obtained a value of 1.86 and 1.97 MPa, respectively, as ascribed to the void filling, according to [ 28 ]. While the higher content of rubber led to the reduction in strength, it was satisfactory until 15% replacement, especially in treating the surface of rubber, say [ 13 ]. According to [ 14 ], the finer rubber particles brought more strength reduction, whereas [ 17 ] indicated a controlled reduction using waste rubber ash. [ 8 – 9 ] concluded that silica fumes, waste glass powder, and rubber fiber treatments effectively mitigate losses; however, [ 6 – 7 ] confirmed that rubberized concrete tensile strength is lower than normal concrete but still viable for pavements, crash barriers, and lightweight structures. This study's experimental findings have been verified like the above statement, as shown in the Fig. 8 the ‘conventional concrete (CC) had a split tensile strength of 3.57’ MPa at 28 days, while the M10G20R0 mix (consisting of 10% metakaolin and 20% GGBS without rubber) showed better performance than CC, a slight increase in strength. Nevertheless, greater rubber content warranted a steady fading of tensile strength; while the M10G20R2.5 mix dropped compared to CC by 18.76%, M10G20R5 showed a reduction of 31.65%. Further increases in rubber content worsened strength losses, with M10G20R7.5 exhibiting a 35.57% reduction and M10G20R10 a 38.10% reduction. Thus, these findings have shown that while rubberized concrete suffers from reduced split tensile strength, such reduction can still be minimized through optimized levels of replacement and the use of supplementary cementitious materials like metakaolin and GGBS for maintaining structural integrity. ‘The Tensile strength was analyzed for 28 days for different mixes.’ The outcomes shows that the tensile strength gradually reduced as the inclusion of WR increases, but the incorporation of mineral admixtures and without WR shows an improve result. The decreased stiffness and decreased bonding efficiency of the rubber particles lead to a weakening of the concrete matrix and, thus, to the loss in its strength. Meanwhile, reasonable tensile capacity appears to be retained by the rubberized mixes, which probably implies some benefits from improved ductility and crack resistance for concrete applications. 5.2.3 Flexural Strength Test An actual study ‘on the effect of waste rubber on the flexural strength of concrete’ has been conducted. [ 4 ] investigated concrete blends with‘rubber fiber and ash as partial fine aggregate’replacements and argued that not exceeding 10% replacement produced a strong mix suitable for pavements and crash barriers. Similarly, but on a different note, [ 6 ] conducted studies using tire shreds at different percentages (2.5–10%) to partially replace fine aggregate and have reported good results in flexural strength. [ 7 ] ‘assessed ‘crumb rubber as a partial replacement of coarse’ aggregates’without giving specific values for flexural strength. [ 8 ] investigated ‘silica fumes and waste glass powder as’ additives to crumb rubber concrete with an emphasis on the mechanics of the latter, particularly flexural strength. The literature mostly describes the reduction of flexural strength in rubber inclusions. [ 20 ] ‘observed a decline in flexural strength with a rubber addition, which findings were also reported by [ 21 – 22 ]. It was noted by noted [ 26 ] that the inclusion of waste tire rubber reduced the flexural strength values, both in normal concrete and fly-ash concrete. According [ 28 ], there was a considerable reduction in workability of foam concrete containing rubber powder, although no details on flexural strength were provided. It was reported that increasing rubber content further reduced flexural strength by [ 30 ]. Quite a few studies, however, have suggested mechanisms for the enhancement of flexural strength in rubberized concrete. There was a suggesting by [ 23 ] for enhancement of flexural strength by addition of nano-silica and metakaolin. It was noted by [ 29 ] that metakaolin enhanced the strength in GGBS ternary concrete over time, although lack of data on flexural strength was noted. Thus, the research indicates waste rubber in general reduces flexural strength, although the modifications can help to alter the effects. The experimental results were in agreement with these studies that show the effect of waste rubber on flexure. As shown in Fig. 9 standard concrete (CC) mix attained a 4.00 MPa flexural strength at 28 days. 10% ‘metakaolin and 20% ground granulated blast-furnace slag,’without rubber replacement, produced the highest strength of the M10G20R0 inclusion by 8.25%. But there was a slow drop in flexural strength as the proportion of waste rubber replacement rose. The M10G20R2.5 recorded the reduction of 10.5%, M10G20R5 was reduced by 14.5%, M10G20R7.5 recorded a 16.75% decrease, while the highest strength loss of 18.75% with the increasing percentage of rubber replacement was observed for M10G20R10 compared to CC. Concrete's flexural strength steadily decreased as the concentration of rubber in the mixture increased. The use of rubber as a fine aggregate substitute resulted in a progressive decrease in flexural capacity, whereas the mix without rubber-maintained strength values greater than the control mix. ‘The reduction in strength’ is primarily due to the lower stiffness and bonding efficiency of rubber aggregates, which impact the load transfer mechanism in the concrete matrix. Despite this reduction, rubberized concrete retains reasonable flexural strength, suggesting potential benefits in applications requiring enhanced toughness and crack resistance. 6. MICROSTRUCTURE AND SPECTROSCOPIC ANALYSIS OF RUBBERIZED CONCRETE 6.1 ‘Scanning Electron Microscopy (SEM) Analysis’ SEM analysis gives a comprehensive analysis of microstructural changes in concrete with varied levels of rubber content. M10G20R0 as shown in Fig. 10 does not contain rubber but reflects the most dense and packed microstructure with very well-formed C-S-H gel and thus, higher porosity. Therefore, it achieves the highest in mechanical strength. The combination of metakaolin and GGBS increases pozzolanic action and refines pore structure, and durability is enhanced. At 2.5% rubber addition to M10G20R2.5, as shown in Fig. 11, the microstructure remains relatively dense, well distributed with hydration products, giving it the highest strength among other rubberized mixes. However, the SEM pictures reveal a weak bond at the rubber-cement interface which comes with microcracks and voids as potential stress concentration points. The higher the rubber content becomes, to 7.5%, the less dense and more extended-out space at M10G20R7.5 as Fig. 12 shows. It is very porous and has an irregular-type microstructure, which can be observed with visible voids and weak interfacial bonding. Incomplete hydration is further corroborated by the presence of unreacted metakaolin and GGBS and enhanced by larger rubber particles with poor adhesion, resulting in low mechanical strength. It has significantly increased porosity and weakened zones around them that form a problem about the structure as a whole. M10G20R10, which has a full 10% rubber replacement, appears to show a more balanced behavior as seen in Fig. 13. The microstructure-involved voids and ITZ between rubber and cement exhibit poor adhesion; however, they benefit from the densification effects of both metakaolin and GGBS, which cause improvements in sulfate resistance and overall durability. The SEM images indicate that while increasing rubber reduces the continuity of the matrix and compressive strength, it enhances ductility and impact resistance. 6.2 Energy-Dispersive X-Ray Spectroscopy (EDS) EDS has been elaborately used to analyze the elemental composition of rubberized concrete. The findings for the rubber replacement percentages of 0%, 2.5%, 7.5%, and 10% are shown in Fig. 14 , which shows the maximum strength attained among the others, followed by the highest strength mid-strength and the lowest strength when combined with WR. Carbon, oxygen, sodium, potassium, calcium, silica, magnesium, aluminium, and sodium are significant components that are present in the spectroscopy findings and tables. Interestingly, the carbon content modifications greatly among M10G20R0 (0% rubber) and M10G20R10 (10% rubber), increasing from 2.89% by weight to 6.59% by weight. This rise in the carbon content indicates that the amount of rubber particles is suitable because rubber is basically a hydrocarbon polymers. Calcium and silicon concentrations, which are also necessary for cement hydration and C-S-H synthesis, show decreasing trends as rubber substitution rises. From 25.96% in M10G20R0 to 20.66% in M10G20R10, calcium has decreased, indicating more cementitious phase decreases that might be associated with possible declines in concrete mechanical strength. Again, silicon presents little variation, lending credence to another idea that higher rubber content dilutes the cementitious matrix. Oxygen content shows minor fluctuations among the different mixtures without any clear trend, perhaps due to interactions between rubber particles and the cement matrix. Magnesium, sodium, aluminium, and potassium are observed to behave closely to the same, suggesting that their influence on the concrete matrix is not much affected by rubber admixture. These variations in elemental composition elucidate their importance for rubber incorporation in microstructural properties. The decrease in calcium and silicon could indicate less‘formation of C-S-H gel,’ which might lead to lower mechanical strength. The increase in carbon content may affect density, porosity, and durability of concrete. From this study, it is evident that rubberized concrete has a sustainable nature dealing with waste products. 6.3 ‘Fourier Transform Infrared Spectroscopy (FTIR) Analysis’ Through FTIR spectra, the variation in chemical bonds for different series of rubberized concrete mixes is presented as shown in Fig. 15 . Transmittance (%) plotted against the wavenumber (cm − 1 ) indicates key functional groups and how they affect the incorporation of rubber into the cementitious matrix. The control mix (M10G20R0) has the highest transmittance, that is, the least organic interference; increased rubber content brings about lower transmittance, signifying a larger presence of organic due to the rubber particles introduced into the mixture. As more rubber is added, absorption peaks associated with hydrocarbons and polymeric structures will continue to increase in intensity. The most important functional groups are found C-H bending (Aromatic/Alkene) at approximately ~ 700 cm − 1 , C-O stretching (Ethers, Esters, Alcohols) at ~ 1100 cm − 1 , C = C stretching (Aromatic/Alkenes) at ~ 1600 cm − 1 , C = O stretching (Carbonyl) at around 1750 cm − 1 . These peaks are characteristic of compounds that are derived from rubber and that increases in intensity as rubber replacement increases. Further evidence of hydrocarbon presence through introduced organic bonds into concrete mixes by rubber is offered by C ≡ C and C ≡ N peaks (Alkynes/Nitriles) at approximately 2200 cm-1 and C-H stretching (Alkanes/Alkenes) at approximately 2900 cm − 1 , respectively. The stronger intensity of C = O and C = C stretching in rubberized mixes indicates that the rubber component interacts with cement hydration products. However, higher contents of rubber may impede the hydration process and reduce ‘the interfacial bond between’cement paste and aggregates. There is an increase in O-H stretch (hydroxyl) at around ~ 3400 cm⁻¹ because of hydration-related interactions in rubberized mixes, suggesting that these mixes can retain some moisture or alter the product hydration. This retained moisture potentially could participate in delayed hydration reactions, which, in turn, could explain the strength recovery seen for some rubberized concrete mixes over time. C-H bending and stretching are indicative of the polymeric material present in the concrete mix from 700 to 3000 cm⁻¹. These compounds induce deformability but could also jeopardize the overall bonding efficiency, which results in a decreased tensile strength due to further rubber contents (especially beyond 5%). It is evident from the transmission spectrum that with increase in rubber percentages, the cement matrix is significantly altered at a structure level which might lead to changes in mechanical performances. The observed peak shifts are indicative that increasing rubber content would lead to handling of rubber-cement interactions through chemical rubber particle pretreatment or introduction of supplementary cementitious material. These ameliorations would strengthen’the interfacial bonding between rubber and cement’paste’and mitigate the corresponding strength losses due to excessive incorporation of rubber. FTIR analysis further brings to a conclusion that rubber replacement produces a significant change in the chemical composition and bond characteristics of the concrete matrix. While small amounts will not have much of a negative impact, larger amounts will bring in organic compounds that interfere with cement hydration and generally compromise structural integrity. 7. CONCLUSION The objectives envisioned for this work include the evaluation ‘of physical properties for cement, fine and coarse’ aggregates, metakaolin, GGBS, and waste rubber, while‘fresh and hardened properties’of M25 grade rubberized concrete with partial fine aggregates replacement by waste fine rubber are being studied at a 0.45 water cement ratio. Besides this, there will be an attempt to establish the optimum rubber replacement percentage for achieving desirable concrete strength and to study microstructural properties of concrete with waste rubbers and mineral admixtures. Using waste rubber as fine aggregate replacement will tend to minimize landfill waste generation and facilitate a circular economy; substituting part of the cement with GGBS and Metakaolin would go a long way in providing the necessary carbon footprint reduction to the already high CO 2 emissions from concrete production in the construction industry. ‘Sustainable Development Goals form part of SDG 9, 12 and 13. Where SDG 9 is Industry, Innovation & Infrastructure, SDG 12 is Responsible Consumption & Production promotes reuse of industrial waste, and finally, SDG 13, which is Climate Action, would reduce carbon emissions during the production of concrete-all in line with the United Nations Sustainable Development Goals (SDGs).’ The evaluation of cement, aggregates, metakaolin, GGBS, and waste rubber for sustainable concrete use was the primary focus of the study. The gradation for M-sand and coarse aggregate satisfied the grading requirements, and OPC 53 Grade has demonstrated high consistency and strength. Strength was eventually improved by the increased pozzolanic activity and microstructure caused by metakaolin and GGBS. The slump value decreased by 18.37% at 10% rubber replacement due to the hydrophobic nature of rubber, reducing workability. Density also dropped by 7.5% compared to conventional concrete. At 28 days, compressive strength increased by 8.8% for the mix containing 10% metakaolin and 20% GGBS with 0% rubber (M10G20R0), but it started to decline with the addition of rubber, falling by 11.8–30.5% as a result of 10% replacement. Due to rubber, split tensile strength also increased by 2.8% for M10G20R0, but dropped by 18.76–38.10%. Flexural strength saw an increase of 8.25%, while rubber replacement yielded a decrease of 10.5–18.75%. An optimal balance was achieved at 2.5% rubber replacement, meeting the M25 strength grade, while higher replacements caused significant strength reductions. Microstructural analyses disclosed modification of the internal structure of concrete by the incorporation of waste rubber and mineral admixtures. Metakaolin and GGBS enhanced hydration and densified the matrix while increasing rubber content imparted more porosity and weaker interfacial bonding, which contributed to lesser strength. Optimal mix at 2.5% rubber replacement gave a balance between microstructural integrity and strength. 8. FUTURE SCOPE To enhance the performance of rubberized concrete, improving bond strength is crucial. This can be achieved through chemical or mechanical pre-treatment of rubber particles, such as NaOH treatment, to enhance adhesion with the cement matrix. Further durability studies should be conducted focusing on water absorption, shrinkage, and resistance to freeze-thaw cycles. Moreover, conducting experiments with higher percentages of waste rubber will help determine the maximum feasible replacement level while maintaining acceptable strength and durability. Lastly, the feasibility of rubberized concrete in lightweight structural components and impact-resistant applications should be explored to expand its potential use in sustainable construction. Declarations Funds This study was conducted without the support of any particular funds from public, private, or nonprofit funding organizations. All costs incurred for the experimental work and analysis were covered by the author. Conflict of Interest The authors declare that there are no financial or personal relationships that could be construed as a conflict of interest in connection with the work submitted. Consent for Publication All authors read and approved the final manuscript. They endorse its submission for publication in the designated journal. The writers certify that the work has never been published before and has not been submitted for publication anywhere else. Author Contribution Freddy Joans Marboh conducted the study, carried out experimental work, conducted the literature review, analyzed the data, and wrote the manuscript. Narasimha Murthy K N contributed in terms of supervision, technical inputs, and critical revisions throughout the research process, ensuring the accuracy and integrity of the study. Both authors read and approved the final version of the manuscript. Data availability Such datasets as generated and analyzed during the course of this study can be made available, on request, and subject to reasonable conditions, from the corresponding author. Supplementary materials or any other information required by the inquirer for replication or follow-up research can be made available upon request. References Li Y, Zhang S, Wang R & Dang F. (2019). Potential use of waste tire rubber as aggregate in cement concrete–A comprehensive review. Construction and Building Materials, 225, 1183-1201. Habib A, Yildirim U & Eren O. (2020). Mechanical and dynamic properties of high-strength concrete with well-graded coarse and fine tire rubber. Construction and Building Materials, 246, 118502. Meng X, Chi Y, Jiang Q, Liu R, Wu K & Li, S. (2019). Experimental investigation on the flexural behavior of pervious concrete beams reinforced with geogrids. Construction and Building Materials, 215, 275-284. Gupta T, Siddique S, Sharma R K & Chaudhary, S. (2021). Investigating mechanical properties and durability of concrete containing recycled rubber ash and fibers. Journal of Material Cycles and Waste Management, 23, 1048-1057. Rashid K, Yazdanbakhsh A & Rehman M. U. (2019). Sustainable selection of the concrete incorporating recycled tire aggregate to be used as a medium to low-strength material. Journal of Cleaner Production, 224, 396-410. Hiremath P, Jayakesh K, Rai R, Raghavendra N S & Yaragal S. (2019). Experimental investigation on utilization of waste shredded rubber tire as a replacement to fine aggregate in concrete. In Sustainable Construction and Building Materials: Select Proceedings of ICSCBM 2018 (pp. 561-569). Springer Singapore. Putri E, Evir H P, Agista G A & Juliafad, E. (2023). Experimental Investigation on the Use of Crumb Rubber as Partial Replacement of Coarse Aggregate in Concrete Incorporating Cement Replacement Materials. GEOMATE Journal, 25(111), 246-253. Singh G, Tiwary K, Singh S, Kumar R, Chohan J S, Sharma S & Deifalla A F. (2022). Incorporation of silica fumes and waste glass powder on concrete properties containing crumb rubber as a partial replacement of fine aggregates. Sustainability, 14(21), 14453. Agrawal D, Waghe U, Ansari K, Dighade R, Amran M, Qader D N & Fediuk R. (2023). Experimental effect of pre-treatment of rubber fibers on mechanical properties of rubberized concrete. Journal of materials research and technology, 23, 791-807. Karimi Pour, Mohajeri Z & Noroozinejad Farsangi E. (2022). Impact of polypropylene fibers on the mechanical and durability characteristics of rubber tire fine aggregate concrete. Materials, 15(22), 8043. Badawi M, Ahmed A G, Eldamaty T A & Helal M. (2023). Properties of Recycled Concrete Utilizing Waste Rubber. Engineering, Technology & Applied Science Research, 13(4), 11451–11458. Abdelmonem A, El-Feky M S, Nasr E S & Kohail M (2019). Performance of High-Strength Concrete Containing Recycled Rubber. Construction and Building Materials, 227, 116660. Kumar R & Dev N. (2021). Mechanical and Microstructural Properties of Rubberized Concrete After Surface Modification of Waste Tire Rubber Crumb. Published by King Fahd University of Petroleum & Minerals Abbas S, Fatima A, Kazmi S, Munir M J, Ali S & Rizvi M A. (2022). Effect of particle sizes and dosages of rubber waste on the mechanical properties of rubberized concrete composite. Applied Sciences, 12(17), 8460. Vignesh R & Abdul Rahim A. (2022). Mechanical and Microstructural Properties of Quaternary Binder System Containing OPC-GGBS-Metakaolin-Lime. Materials Today: Proceedings. Al-Oran A, Safiee N A & Nasir N A. (2019). Fresh and Hardened Properties of Self-Compacting Concrete Using Metakaolin and GGBS as Cement Replacement. European Journal of Environmental and Civil Engineering. Nikkhah H, Tavakoli H R & Fallah N. (2023). Experimental investigation of the effects of using waste rubber ash on mechanical properties of plain concrete. International Journal of Engineering, Transactions C: Aspects, 36(3), 450-456. Kumar D C & Vasanthi P. (2022). Effect of coarse and fine GGBS in mechanical properties of concrete. Materials Today: Proceedings, 68, 1594–1598. Elavarasan S, Priya A K, Ajai N, Akash S, Annie T J & Bhuvana G. (2020). Experimental study on partial replacement of cement by metakaolin and GGBS. Materials Today: Proceedings. Kadhim A A & Al-Mutairee H M K. (2020). An experimental study on the behavior of sustainable rubberized concrete mixes. Civil Engineering Journal. Ahmad J, Zhou Z, Majdi A, Alqurashi & Deifalla A F. (2022). Overview of concrete performance made with waste rubber tires: A step toward sustainable concrete. Materials, 15(16), 5518. Gupta T, Chaudhary S, & Sharma R K. (2014). Assessment of mechanical and durability properties of concrete containing waste rubber tire as fine aggregate. Construction and Building Materials, 73, 562–574. Chalangaran N, Farzampour A & Paslar N. (2020). Nano silica and metakaolin effects on the behavior of concrete containing rubber crumbs. Civil Engineering, 1(3), 264–274. Appana P M, Mohammed B, Abdulkadir I, Ali M & Liew M S. (2022). Mechanical, microstructural, and drying shrinkage properties of NaOH-pretreated crumb rubber concrete: RSM-based modeling and optimization. Materials, 15(7), 2588. Mhaya A M, Abidin A, Sarbini N & Ismail M. (2019). Role of crumb tyre aggregates in rubberised concrete contained granulated blast-furnace slag. IOP Conference Series: Earth and Environmental Science, 220(1), 012029. Fauzan Nur O F, Albarqi K, Melinda A. P & Jauhari Z A. (2021). The effect of waste tyre rubber on mechanical properties of normal concrete and fly ash concrete. International Journal of GEOMATE, 20(77), 55–61. Aneel Manan, Pu Zhang, Wael Alattyih, Hani Alanazi, S.K. Elagan, and Jawad Ahmad. "Mechanical and Microstructural Characterization of Sustainable Concrete Containing Recycled Concrete and Waste Rubber Tire Fiber." Materials Research Express, 2024, in press. Mehrani S A, Bhatti I. A, Bhatti N. B, Jhatial A & Lohar M. A. (2019). Utilization of rubber powder of waste tyres in foam concrete. Journal of Applied Engineering Sciences, 9(22), 87-90. https://doi.org/10.2478/jaes-2019-0011 Nasir N. A. M. & McCarthy M. J. (2014). Effect of metakaolin on early strength of GGBS ternary concrete. Applied Mechanics and Materials, 584–586, 1551–1557. Abdullah W. A, Muhammad M. A & Abdulkadir M. R. (2020). Experimental investigation of some mechanical properties of rubberized concrete with highest possible rubber content. Journal of University of Duhok, 23(2), 509-522. Ibrahim O. M. O & Tayeh B. A. (2020). Combined effect of lightweight fine aggregate and micro rubber ash on the properties of cement mortar. Advances in Concrete Construction, 10(6), 537–546. Banerjee S, Mandal A & Rooby J. (2019). Performance of modified rubber aggregate concrete with GGBS and silica. International Journal of Innovative Technology and Exploring Engineering, 9(2), 2438–2442. Bureau of Indian Standards. (1988). IS 4031:1988 – Methods of physical tests for hydraulic cement. New Delhi, India: Bureau of Indian Standards. Bureau of Indian Standards. (1963). IS 2386 (Part 3):1963 – Methods of test for aggregates for concrete: Part 3 Specific gravity, density, voids, absorption and bulking. New Delhi, India: Bureau of Indian Standards. Bureau of Indian Standards. (2019). IS 10262:2019 – Guidelines for concrete mix proportioning. New Delhi, India: Bureau of Indian Standards. Bureau of Indian Standards. (1959). IS 516: Method of tests for strength of concrete. Bureau of Indian Standards. Bureau of Indian Standards. (1959). IS 1199:1959 – Methods of sampling and analysis of concrete. New Delhi, India: Bureau of Indian Standards. ASTM International. (n.d.). Standard test methods for specific gravity and absorption of fine aggregate (ASTM D854) Bureau of Indian Standards. (2016). IS 383:2016 – Coarse and fine aggregate for concrete – Specification (Third Revision). Bureau of Indian Standards. ASTM International. (2018). ASTM D1509-18: Standard test method for carbon black – Heating loss. ASTM International. British Standards Institution. (1992). BS 6699:1992 – Specification for ground granulated blast-furnace slag for use with Portland cement. British Standards Institution. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-6264503","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":434375204,"identity":"40a0761d-c282-41db-a9bb-77062aabf2c1","order_by":0,"name":"Freddy Joans Marboh","email":"","orcid":"","institution":"CHRIST (Deemed to be University),","correspondingAuthor":false,"prefix":"","firstName":"Freddy","middleName":"Joans","lastName":"Marboh","suffix":""},{"id":434375205,"identity":"01a295ee-5b7d-4c32-9e7d-07e093bdbd5c","order_by":1,"name":"Narasimha Murthy K N","email":"data:image/png;base64,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","orcid":"","institution":"CHRIST (Deemed to be University),","correspondingAuthor":true,"prefix":"","firstName":"Narasimha","middleName":"Murthy K","lastName":"N","suffix":""}],"badges":[],"createdAt":"2025-03-19 21:08:10","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6264503/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6264503/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":79803399,"identity":"9372b55e-035a-4e1c-a112-26eed7ddf420","added_by":"auto","created_at":"2025-04-03 04:41:39","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":58918,"visible":true,"origin":"","legend":"\u003cp\u003eParticle size distribution curve of Fine and Coarse aggregate’\u003c/p\u003e","description":"","filename":"1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6264503/v1/47884cd0a2e8d5f824f43ad9.jpg"},{"id":79803650,"identity":"c337d43d-da22-42dc-a999-ae85137787ff","added_by":"auto","created_at":"2025-04-03 04:49:39","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":87514,"visible":true,"origin":"","legend":"\u003cp\u003eWaste rubber used in concrete\u003c/p\u003e","description":"","filename":"2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6264503/v1/a58c2bed7456b60aa7c2efe6.jpg"},{"id":79803401,"identity":"7258b2a9-a37a-46df-8e79-34f240c197d8","added_by":"auto","created_at":"2025-04-03 04:41:39","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":64827,"visible":true,"origin":"","legend":"\u003cp\u003eGGBS particles under SEM\u003c/p\u003e","description":"","filename":"3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6264503/v1/5233fc9c26920ca61bef95cb.jpg"},{"id":79803651,"identity":"eea6ac19-db61-42a7-90af-bbbe3b5110a5","added_by":"auto","created_at":"2025-04-03 04:49:39","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":67230,"visible":true,"origin":"","legend":"\u003cp\u003eMetakaolin Particles under SEM\u003c/p\u003e","description":"","filename":"4.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6264503/v1/c081f207fd925af03590f566.jpg"},{"id":79803404,"identity":"1f331a83-234a-4629-a946-228e503078e9","added_by":"auto","created_at":"2025-04-03 04:41:39","extension":"jpg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":37672,"visible":true,"origin":"","legend":"\u003cp\u003eSlump difference in rubberized concrete\u003c/p\u003e","description":"","filename":"5.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6264503/v1/f78d286fb8d204be86e1c063.jpg"},{"id":79803402,"identity":"e20c97b4-dda7-46be-9d46-57d5a90c8390","added_by":"auto","created_at":"2025-04-03 04:41:39","extension":"jpg","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":42338,"visible":true,"origin":"","legend":"\u003cp\u003eVariation of Density in concrete\u003c/p\u003e\n\u003cp\u003eNote: CC refers to Conventional concrete, M refers to Metakaolin, G refers to GGBS and R refers to waste rubber\u003c/p\u003e","description":"","filename":"6.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6264503/v1/7b5f29f242e46ddf6b75d45a.jpg"},{"id":79803652,"identity":"4bd28775-4cf8-4daa-be08-59c852e85021","added_by":"auto","created_at":"2025-04-03 04:49:39","extension":"jpg","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":57279,"visible":true,"origin":"","legend":"\u003cp\u003eCompressive strength of Rubberized concrete\u003c/p\u003e","description":"","filename":"7.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6264503/v1/eb10fc99dfb271e829a7fb8f.jpg"},{"id":79803405,"identity":"980e82c7-45fa-4b11-83aa-79571bb84ad9","added_by":"auto","created_at":"2025-04-03 04:41:39","extension":"jpg","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":57531,"visible":true,"origin":"","legend":"\u003cp\u003eSplit Tensile strength of rubberized concrete\u003c/p\u003e","description":"","filename":"8.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6264503/v1/b9cc6bf189a39bb241a6af41.jpg"},{"id":79804187,"identity":"a9f35c7b-c8a8-498b-be1f-42ff5ec1c9ca","added_by":"auto","created_at":"2025-04-03 04:57:40","extension":"jpg","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":59365,"visible":true,"origin":"","legend":"\u003cp\u003eFlexural Strength of Rubberized concrete’\u003c/p\u003e","description":"","filename":"9.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6264503/v1/24560896bdddafd585d2053a.jpg"},{"id":79804188,"identity":"97e3e972-1ebb-472a-ba6a-556dfe1fab33","added_by":"auto","created_at":"2025-04-03 04:57:40","extension":"jpg","order_by":10,"title":"Figure 10","display":"","copyAsset":false,"role":"figure","size":51196,"visible":true,"origin":"","legend":"\u003cp\u003eSEM image for M10G20R0 concrete\u003c/p\u003e","description":"","filename":"10.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6264503/v1/9e67e4c6caf58be821c9aef4.jpg"},{"id":79803659,"identity":"992b80bb-6189-4b7e-8cf9-8e1da9cb7ea0","added_by":"auto","created_at":"2025-04-03 04:49:40","extension":"jpg","order_by":11,"title":"Figure 11","display":"","copyAsset":false,"role":"figure","size":65286,"visible":true,"origin":"","legend":"\u003cp\u003eSEM image for M10G20R2.5 concrete\u003c/p\u003e","description":"","filename":"11.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6264503/v1/7a68f931f649572bab644644.jpg"},{"id":79803419,"identity":"02038ed8-a431-4ad3-9a64-5c2343aaf520","added_by":"auto","created_at":"2025-04-03 04:41:40","extension":"jpg","order_by":12,"title":"Figure 12","display":"","copyAsset":false,"role":"figure","size":58311,"visible":true,"origin":"","legend":"\u003cp\u003eSEM image on M10G20R7.5 concrete\u003c/p\u003e","description":"","filename":"12.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6264503/v1/bba5ebafbc4aafb61f6d6ce8.jpg"},{"id":79804189,"identity":"fccf3ad0-97d9-4864-bcf3-08c6f71b9fa9","added_by":"auto","created_at":"2025-04-03 04:57:40","extension":"jpg","order_by":13,"title":"Figure 13","display":"","copyAsset":false,"role":"figure","size":52479,"visible":true,"origin":"","legend":"\u003cp\u003eSEM image on M10G20R10 concrete\u003c/p\u003e","description":"","filename":"13.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6264503/v1/7dea922059ce6767d0aa5092.jpg"},{"id":79803434,"identity":"f8d98dd4-7a57-4bc7-9995-94eced5f59cc","added_by":"auto","created_at":"2025-04-03 04:41:40","extension":"jpg","order_by":14,"title":"Figure 14","display":"","copyAsset":false,"role":"figure","size":99862,"visible":true,"origin":"","legend":"\u003cp\u003eEDS Image on variances of rubberized concrete\u003c/p\u003e\n\u003cp\u003eNote: The EDS findings when doing SEM analysis are displayed in Figure 19. The table displays the weight of the various materials found in the concrete, and the image displays the presence of the various elements in various levels of rubber addition.\u003c/p\u003e","description":"","filename":"14.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6264503/v1/b6630b638894f2d4de353591.jpg"},{"id":79803669,"identity":"fb857687-4400-479b-866f-83914a5b0510","added_by":"auto","created_at":"2025-04-03 04:49:40","extension":"jpg","order_by":15,"title":"Figure 15","display":"","copyAsset":false,"role":"figure","size":83115,"visible":true,"origin":"","legend":"\u003cp\u003eFTIR analysis on rubberized concrete\u003c/p\u003e","description":"","filename":"15.jpg","url":"https://assets-eu.researchsquare.com/files/rs-6264503/v1/599b4729b84900398a775dda.jpg"},{"id":80472964,"identity":"ceb3dad7-960b-443d-9575-dc44e7069585","added_by":"auto","created_at":"2025-04-13 09:01:41","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2038081,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6264503/v1/bdf45736-a193-4ee2-84e9-37a59d09237c.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Development of rubberized concrete with mineral admixtures for sustainable concrete","fulltext":[{"header":"1. INTRODUCTION","content":"\u003cp\u003e \u003cdiv class=\"BlockQuote\"\u003e \u003cp\u003eConcrete, then, is acknowledged to be\u0026rsquo;the most widely\u0026rsquo;\u0026rsquo;consumed construction material on the planet because of its fascinating strength, durability, and adaptability. It remains to form a considerable part in the construction of buildings, roads, bridges, etc., the list goes on, and hence why the substance is crucial in the contemporary infrastructure development that lies beneath urbanization and economy [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Concrete is an irreplaceable material for \u0026lsquo;the construction industry\u0026rsquo;owing to its great compressive strength, fire-resistance ability, and long service life [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. However, because of these increasing demands for concrete, many environmental concerns grew. Cement, an important binder for concrete, produces nearly 8% of global anthropogenic CO₂ emissions [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. Furthermore, environmental deterioration, including habitat damage and river bed depletion, has been brought on by the extraction of natural resources such river sand for fine aggregates [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. Researchers are now looking on sustainable substitutes for traditional concrete ingredients that can preserve or improve performance as a result of these difficulties [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eWhile the concrete industry has enjoyed reliable properties and multipurpose applications, it also presents serious problems regarding resources and the environment. The over-extraction of natural fine aggregates or river sand, poses an obstacle to sustainable construction methods by leading to habitat destruction, erosion, and river bed depletion [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e], [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. Calcining limestone and burning fossil fuels account for nearly 8% of world CO₂ emissions; hence, cement sector is one of the major sources of CO₂ emissions [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e], [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. Water is also used in very high amounts, causing further depletion of resources [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eEnvironmental issues of sorts have become more and more an issue of sorts with an estimated 1.5\u0026nbsp;billion tires being disposed annually in some way or the other [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Most of these tires are taken stock of, or landfilled illegally dumped. This causes severe environmental problems. Tires are tough and non-biodegradable. They would take hundreds of years to decompose while in a landfill, thus occupying precious areas of the latter [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. Also, such as the nature of conveniently disposed tires that they often form large heaps which become incredibly difficult to extinguish at fire time. As a result, harmful smoke is released, contaminating the air and negatively affecting nearby communities [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e], [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e], [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. On the basis of waste tires, the hazardous chemicals like oils and carbon black can seep into the groundwater and soil, causing chronic contamination that interferes with ecosystem processes and poses a serious threat to human health [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e], [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. In addition, inappropriate disposal of waste tires amount to the loss or repurposing of valuable raw materials that can be recycled or reused: rubber, steel and carbon black thus considered an enormous waste of materials [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e], [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. The ecological and resource-related plights must pose greater prospects for sustainable development in waste tire management [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e], [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e], [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eRubber particles substitute conventional fine aggregates such as sand and thus reduce the demand for natural resources and landfill space [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e], [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. On the other hand, recycling rubber minimizes fire hazards and toxic emissions from stockpiled tires and also bolsters the circular economy [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e], [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e], [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. Rubberized concrete has increased resistance to impact, flexibility, and thermal insulation, making it appropriate for use in pavements and noise barriers [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e], [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]. Though it tends to lower compressive strength, various researchers are studying mix designs and some additives like GGBS and fibers to achieve higher strength [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e], [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]. This approach also has a definite advantage in terms of sustainability as by minimizing waste, conserving resources, and completing the cycle in the circular economy [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e], [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e], [\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e\u0026lsquo;The use of waste rubber as a partial substitute for fine aggregates in concrete\u0026rsquo; presents a number of mechanical in nature, durability, and workability issues. Because rubber is softer than natural aggregates, it creates weak spots in the \u0026lsquo;concrete matrix, which lowers the concrete's tensile and \u0026lsquo;compressive strength\u0026rsquo;[\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e], [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. Besides, the rubberized concrete tends to have more air contents, less density, and different water-cement interactivity, which usually calls for adjustments for mix proportioning or the addition of plasticizers [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e], [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. Issues arising from water absorption and shrinkage call for durability concerns that can very well be treated with surface treatments and optimized mix designs [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e], [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. Adding more cementitious ingredients to concrete has the potential to improve \"its strength and overall performance characteristics.\u0026rsquo;For example, metakaolin and GGBS have been proven to be beneficial for rubberized concrete mixes [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e], [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e], [\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e] thus creating an avenue for sustainable exploitation in construction applications.\u003c/p\u003e \u003cp\u003eVery limited studies were conducted on the combined application of waste rubber as fine aggregate and mineral admixtures like GGBS and Metakaolin to counter the weaknesses of rubberized concrete. Although studies have investigated independently the merits of GGBS and Metakaolin in terms of advancing the concrete strength and durability [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e], [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e] [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e], [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e], not so much has been paid attention to finding their synergistic effects with the rubber particles. Their combined potential to reverse that scenario discovered in rubberized concrete by having the activities of countering the opposing effects of loss of compressive strength thereby improving bonding and refining the microstructure need to be examined further [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e], [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e].\u003c/p\u003e \u003c/div\u003e \u003c/p\u003e"},{"header":"2. LITERATURE REVIEW","content":"\u003cp\u003e \u003cdiv class=\"BlockQuote\"\u003e \u003cp\u003eWaste tire rubber incorporation in concrete is an area of extensive investigation by researchers seeking to evaluate this material's potencies\u0026rsquo;as a sustainable alternative to conventional aggregates.\u0026rsquo;\u0026rsquo;The comprehensive\u0026lsquo;use of waste tire rubber in cement concrete,\u0026rsquo; cited in several literatures for its promising effects of reducing environmental pollution and enhancing thermal and acoustic insulation properties for concrete. However, they cited limited work done in the reduction in mechanical strength, an issue that reappears time and again in other studies that followed by [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e], [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e] examined a high-strength concrete's \"mechanical and dynamic\" characteristics using \"well-graded coarse and fine tire rubber.\" According to their findings, adding rubber particles to the concrete decreased its \"compressive strength\" while increasing its ductility and energy-absorbing ability. Thus, this type of high-strength concrete can be used for impact-resistant applications.\u003c/p\u003e \u003cp\u003eThe good thing about using pervious concrete in stormwater management with an insight into its low flexural strength. To enhance structural performance, reinforcement with geogrid has been studied by [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]: it improves load-bearing capacity and ductility. Following this, the study experimentally investigates \u0026lsquo;the outcome of layers of geogrid on the flexural behaviour of pervious concrete beams.\u0026rsquo;Research on the mechanical attributes of rubberized concrete is relatively popular. Mechanical as well as durability properties were investigated in concrete that used recycled rubber ash and fibers by [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e], they concluded that rubber ash and fibers contribute to flexural strength and toughness in concrete, although a slight \u0026lsquo;decrease in compressive strength\u0026rsquo; was noted. On the other hand, [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e] researched green selection \u0026lsquo;of concrete with recycled tire aggregate\u0026rsquo;for structural applications from medium to low strength and concluded that rubberized concrete could indeed be possibly non-structural applications for which high strength is not an overall requirement.\u003c/p\u003e \u003cp\u003eExperimental studies were also conducted by [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e], which involved use of waste shredded tire rubber as substitute for fine aggregate in concrete. Results indicated lower compressive strength when the amount of rubber is increased\u003c/p\u003e \u003cp\u003ein concrete mixes, yet showed improved impact resistance as well as ductility. This was supported by [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e], who assessed the properties of using crumb rubber in concrete to partially substitute coarse aggregate; the inclusion of crumb rubber improved the energy absorption of the concrete. Hence, it became suitable for use in pavements and structures that require shock absorption. Several investigations have been conducted concerning \u0026lsquo;the mechanical properties of rubberized concrete.\u0026rsquo; Mechanical and durable properties of concrete containing recycled rubber ash and fibers studied by\u0026rsquo;[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e], they concluded that with the addition of rubber ash and fibers, the bronchial strength and toughness were enhanced, although a little reduction is also observed in compressive strength. In another study, [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e] analyzed the sustainable selection of using recycled tire aggregate within concrete to serve medium and low strength applications, admitting that rubberized concrete was possible \u0026lsquo;for non-structural applications that did not require high strength.\u0026rsquo; The experimentally was proved by [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e], that leftover shredded rubber tires are used \u0026lsquo;in place of fine aggregate in concrete.\u0026rsquo; The findings show that while\u0026lsquo;\u0026rsquo;the compressive strength declined as\u0026rsquo;the percentage\u0026rsquo; of rubber increased, concrete's ductility and impact resistance improved. This was further supported by [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e], who studied crumb rubber as a partial \u0026lsquo;replacement for coarse aggregate in concrete.\u0026rsquo;\u0026rsquo;The presence of crumb rubber also enhanced energy absorption capacity of the concrete, making it applicable in use for pavements and shock-absorbing structures.\u003c/p\u003e \u003cp\u003eAdditional investigations have been continued in order to evaluate the durability aspect of rubberized concrete where, [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e] revealed the results of a study on the effects of waste glass powder and silica fumes in crumb rubber cement, where the crumb rubber was used to partially substitute fine aggregates. They came to the conclusion that waste glass powder and silica fumes enhance the mechanical qualities and longevity of rubberized concrete, mitigating some of the negative impacts of rubber on strength. In a recent paper, [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] examined how the mechanical characteristics of rubberized concrete were affected by the pre-treatment of rubber fibers. According to their findings, pre-treating rubber fibers strengthened the cement matrix's bond with rubber, improving the material's mechanical qualities and [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]\u0026rsquo;investigated the impact of the addition of polypropylene fibers on the mechanical and lasting properties\u0026rsquo;of\u0026rsquo; rubber tire fine aggregate concrete, coming to the conclusion that adding polypropylene fibers improves the concrete's tensile strength and durability, increasing its resistance to environmental deterioration and cracking\u003c/p\u003e \u003cp\u003eMany studies have been conducted on blending utilized the supplementary cementitious \u0026lsquo;materials to enhance the concrete performance.\u0026rsquo;The study results of [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e] indicated that high strength concrete has a better performance with the use of metakaolin and \u0026lsquo;GGBS\u0026rsquo;with regard to compressive strength and durability. Mechanical and microstructural properties of concrete studied by [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e] and [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e] analyzed the influence of rubber waste particle sizes and dosages on mechanical properties of rubberized concrete composite and found that with small rubber particles, low dosages would better improve the mechanical properties, especially when used with supplementary cementitious materials.\u003c/p\u003e \u003cp\u003eNow, the microstructure of rubberized concrete is one of the main research areas where, [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]\u0026lsquo;studied the\u003c/p\u003e \u003cp\u003e\u0026lsquo;Mechanical and microstructural properties of a quaternary binder system with OPC, GGBS, metakaolin, and lime.\u0026rsquo; It was concluded that the incorporation of metakaolin and GGBS enhanced the microstructural properties of concrete, hence improving its mechanical properties and then [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e] studied the\u0026rsquo;fresh and hardened properties of self-compacting \u0026lsquo;concrete using metakaolin and GGBS as cement\u0026rsquo; conversions. \u0026rsquo;They reported that the use of these materials increased the workability and strength of the concrete, especially in view of its wide field of applications.\u003c/p\u003e \u003cp\u003eThe various studies have also emphasized on the environmental and economic advantages of using waste tire rubber in concrete construction. Giving a full review of performance in using waste rubber tires in concrete, [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e] mentioned the opportunity to reduce landfill waste and\u0026lsquo;lower the carbon footprint of concrete production,\u0026rsquo;[\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e] \u0026lsquo;evaluated the\u0026rsquo;mechanical and durability properties of concrete\u0026rsquo;with\u0026rsquo;rubber waste tires as fine aggregate\u0026rsquo;and noted that the incorporation of rubber into concrete will lead to sustainable construction practices while maintaining acceptable performance levels. Most of the innovation-oriented work in rubberized concrete has now been completed. Research of [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e] demonstrates that rubber powder from discarded tires has improved properties for foam concrete making it more thermally and acoustically effective. The authors [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e], revealed that in their \u0026lsquo;mechanical and microstructural analysis of sustainable concrete, using recycled concrete with waste rubber\u0026rsquo;tire fibers holds a bright potential for structural applications of rubberized concrete. Experimental study was performed by [\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e] on rubberized concrete for containing the highest rubber content, examining mechanical properties. The study showed that increased rubber content would have a significant impact on both compressive and tensile strengths, with reduction, which is a result of the lower stiffness of rubber compared to conventional aggregate. However, improvements were found in energy absorption and impact resistance, making rubberized concrete a candidate for applications where high toughness is required and [\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e] also studied the \u0026lsquo;combined effect of lightweight fine aggregate and micro rubber ash on properties of cement mortar.\u0026rsquo; The study findings showed that micro rubber ash inclusion enhanced the morphology and durability of cement mortar, eventually reducing density, and indicated the potential use of such materials for green and lightweight construction. Another study was conducted by [\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e], which argued about the nature of \u0026lsquo;performance of rubber aggregate concrete modified with GGBS and silica.\u0026rsquo;\u003c/p\u003e \u003c/div\u003e \u003c/p\u003e"},{"header":"3. ‘MATERIALS’","content":"\u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003e3.1 \u0026lsquo;Cement\u0026rsquo;\u003c/h2\u003e \u003cp\u003e\u0026lsquo;Ordinary Portland Cement of 53 Grade is used\u0026rsquo;as per IS 4031:1988 [\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e]. Specific gravity by the Le Chatelier flask method is 3.11. The consistency of cement was determined to be 34%.\u0026lsquo;Initial setting time and final setting time\u0026rsquo; by Vicat apparatus were recorded as 80 and 320 minutes, respectively. Cement fineness was determined with 8% retained on a 90-micron sieve. Dark grey colour was observed in the cement. \u0026lsquo;The chemical composition is shown in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u0026rsquo;\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003e\u0026lsquo;Chemical composition of Ordinary Portland Cement (OPC 53) and mineral admixtures\u0026rsquo;\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eChemical Name\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCement Mass (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eGGBS Mass (%)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eMetakaolin Mass (%)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSilica (SiO₂)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e21.25\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e34.81\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e70.4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAlumina (Al₂O₃)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4.33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e17.92\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e21.85\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFerric Oxide (Fe₂O₃)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.85\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.66\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.38\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTitanium Oxide (TiO₂)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCalcium Oxide (CaO)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e64.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e37.63\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.17\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMagnesium Oxide (MgO)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.81\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.47\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSodium Oxide (Na₂O)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.17\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.47\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePotassium Oxide (K₂O)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.71\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.63\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLoss On Ignition (LOI)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-0.35\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eManganese Oxide (MnO)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eChlorine (Cl)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.004\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eInsoluble Residue (IR)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.19\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSulfur Trioxide (SO₃)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.58\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSulphide Sulphur\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.51\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePhosphorus Pentoxide (P₂O₅)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.63\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eTitanium Dioxide (TiO₂)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.02\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eVanadium Pentoxide (V₂O₅)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.02\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eStrontium Oxide (SrO)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.01\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"4\"\u003e\u003cb\u003e\u0026lsquo;Note\u003c/b\u003e: OPC: Ordinary Portland Cement, GGBS: Ground Granulated Blast Furnace Slag\u0026rsquo;\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003e3.2 \u0026lsquo;Fine Aggregates\u0026rsquo;\u003c/h2\u003e \u003cp\u003e\u0026lsquo;M-sand used in the present study as a fine aggregate conforming to IS 2386:1963\u0026rsquo; [\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e]. According to standard grading specifications, going through a 4.75 mm sieve qualified the M-sand into Zone II grading. The characterization of fine aggregate gave specific gravity equal to 2.47 giving the density in respect to water, while the fineness modulus is identified as 2.85, giving it the attribute of being coarse. Particle size distribution, as shown in Fig.\u0026nbsp;1, gives overall insight into the gradation and suitability of the fine aggregate for the concrete mix.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003e2.3 \u0026lsquo;Coarse Aggregates\u0026rsquo;\u003c/h2\u003e \u003cp\u003e\u0026lsquo;The coarse aggregate employed in this investigation was material maintained on a 4.75 mm screen with a maximum particle size of 20 mm, in accordance with IS 2386:1963\u0026rsquo; [\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e] and IS 383:2016 [\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e] standards. The physical parameters of the coarse aggregate were carefully investigated, revealing a specific gravity of 2.66, which shows its density in relation to water. Furthermore, the fineness modulus was estimated as 7.45, demonstrating the aggregate's gradation and particle size dispersion. The water absorption rate was determined at 0.75%, indicating that the material can retain moisture. Figure\u0026nbsp;1 depicts the coarse aggregate's detailed particle size distribution, which provides more insight into its appropriateness for use in concrete manufacturing.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003e2.4 materials Additive\u003c/h2\u003e \u003cdiv id=\"Sec8\" class=\"Section3\"\u003e \u003ch2\u003e2.4.1 Waste rubber\u003c/h2\u003e \u003cp\u003eAccording to ASTM D854 [\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e], \u0026lsquo;waste rubber (WR), having a specific gravity of 1.2 and a particle size of 40 mesh or 0.425 mm, water absorption and moisture content was observed to be\u0026rsquo; 0.77% and 0.82% which was tested as per the ASTM D1509 [\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e] guidelines, it was procured from a well-known supplier based in the Peenya Industrial Area, Bangalore. This waste rubber was selected for \u0026lsquo;partial replacement of fine aggregates in concrete,\u0026rsquo; with carefully chosen replacement levels of 2.5%, 5%, 7.5%, and 10% by volume. As can be seen in Fig.\u0026nbsp;2 (a), the waste rubber appears black in colour, indicating that it is in processed form. Before the WR was introduced into the concrete mixing, it was cleaned properly as shown in Fig.\u0026nbsp;2(b) where every particle was washed with clean water to ensure that no dirt or impurities could possibly remain. Then the rubber particles were laid to dry for 24 hours in order to make certain that they were free of moisture, which is required for a good mixing of WR with the other constituents of concrete. Whereas Fig.\u0026nbsp;2(c) as \u0026lsquo;it can be seen from the SEM image shown,\u0026rsquo; the WR has an irregular in shape and some of the sharp edges present. It enhances the interlocking but due to irregular in shape it may present voids around the corners, the particles' shape makes it simple to trap air around them.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec9\" class=\"Section3\"\u003e \u003ch2\u003e2.4.2 \u0026lsquo;Ground Granulated Blast Furnace Slag (GGBS)\u0026rsquo;\u003c/h2\u003e \u003cp\u003e\u0026lsquo;The physical characteristics of the GGBS utilized in this investigation are shown in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e.\u0026rsquo; and it meets the requirements for concrete applications as stated in BS 6699 [\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e]. GGBS was frequently used at a predetermined amount of 20% as a \u0026lsquo;partial cement replacement to enhance the properties of concrete.\u0026rsquo; Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e displays the chemical makeup. As shown In Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e3\u003c/span\u003e this SEM image of GGBS at 5000\u0026times; magnification reveals angular, fractured, and irregular particles with smooth and rough textures, enhancing reactivity in concrete. The layered or striated surfaces suggest internal fracturing, improving cement hydration. Fine debris indicates mechanical grinding effects. The 10 \u0026micro;m scale bar demonstrates its ultra-fineness captured by an ETD detector at 10.00 kV. These characteristics help to bond more thoroughly and facilitate\u0026lsquo;the formation of more C-S-H gel,\u0026rsquo; leading to improved \u0026lsquo;strength and durability of concrete.\u0026rsquo;\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec10\" class=\"Section3\"\u003e \u003ch2\u003e2.4.3 Metakaolin (MK)\u003c/h2\u003e \u003cp\u003eTo ensure its quality and uniformity, the metakaolin used in this investigation was manufactured in accordance with IS 4031: 1988 [\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e]. Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e displays the physical characteristics, whereas Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e displays the chemical composition. \u0026lsquo;In order to improve some of the mechanical and durability features of concrete,\u0026rsquo; a constant percentage of 10% was added to the mix by partially substituting cement with metakaolin. By lowering the need for traditional cement, this continuous replacement would not only enhance the overall performance of concrete but also guarantee environmentally friendly and sustainable practices in the building sector. The SEM image as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e4\u003c/span\u003e of metakaolin shows the heterogeneous, angular, plate-like particles with significant aggregation at a 5000\u0026times; view, suggestive of a large surface area and pozzolanic activity. Through increased reactivity with cement hydrates, this roughness enhances mechanical characteristics. These fine powders, size ranges submicron to micrometre, enable metakaolin to \u0026lsquo;fill the voids within the cement matrix and react with calcium hydroxide to increase both compressive and flexural strengths of the resulting cement.\u0026rsquo;\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003ePhysical Properties of GGBS and Metakaolin\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eProperty\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eGGBS\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMetakaolin\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePhysical State\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePowder\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMicronized Powder\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eOdour\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eOdourless\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eOdourless\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eColor\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eLight Grey\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003ewhite\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003epH (10% solids)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e10\u0026ndash;12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4.5\u0026ndash;5.5\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBulk Density (kg/m\u0026sup3;)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1000\u0026ndash;1200\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e400\u0026ndash;500\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSpecific Surface Area (m\u0026sup2;/g)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e400\u0026ndash;600\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e19\u0026ndash;20\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSpecific Gravity\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2.4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eWater Absorption (g/100g)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNegligible\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eFineness (m\u0026sup2;/kg)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e275 (Min)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e441\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLoss on Ignition (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;3.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.33\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eGlass Content (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eHigh (70%+)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMK Content (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e97.0% MIN\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eReactive with Lime (MgCa(OH)₂/gm)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eModerate\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1000\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eReactive with Lime (MPa)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eModerate\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMoisture Content (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u0026lt;\u0026thinsp;0.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.5\u0026ndash;1.0\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eChemical Modulus (CaO\u0026thinsp;+\u0026thinsp;MgO\u0026thinsp;+\u0026thinsp;SiO₂)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eHigh (60%+)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"3\"\u003e\u0026lsquo;Note: GGBS: Ground Granulated Blast Furnace Slag\u0026rsquo;\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"4. EXPERIMENTAL INVESTIGATION","content":"\u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003e4.1 Methodology\u003c/h2\u003e \u003cp\u003eExperimental design of M25 concrete grade was conducted. Six diverse mixes were made where by one\u0026mdash;the control mix\u0026mdash;remains standard concrete without the additions, while the rest mixed have supplementary cementing materials and varying amounts of waste rubber. The waste rubber was considered a partial fine aggregate replacement in proportions of 2.5%, 5%, 7.5%, and 10%. Different mechanical axial strength tests were performed on the mixes for the curing days of 7, 14, and 28 in order to assess performance. The basic objective of introducing SCMs was to enhance the concrete properties while the effects of varying proportions of rubber were studied for strength characteristics. CC means Conventional Concrete, while M10G20R0, M10G20R2.5, M10G20R5, M10G20R7.5, and M10G20R10 correspond to different mixes. In these compositions, metakaolin (M) is constant at 10% as a cement by volume replacement, while GGBS (G) is fixed at 20% by cement volume replacement, and waste rubber (R) is used to replace fine aggregate at 0%, 2.5%, 5%, 7.5%, and 10%, respectively.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003e4.2 Sample preparation\u003c/h2\u003e \u003cp\u003eA total of 18 samples, including cubes and cylinders, were cast for each concrete mix, namely conventional concrete (CC), and blended concrete mixes containing supplemental cementitious materials and waste rubber. The samples were designed to test the compressive and tensile strength of concrete at different curing times. In addition, 9 beam samples were cast for each mix of conventional concrete and blended concrete to determine the flexural strength. Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e shows the exact percentage proportions of the elements in each mix, including cement fine aggregates, metakaolin, GGBS, and waste rubber, giving a detailed view of the mix design.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003ePercentage replacement levels\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMix\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCement %\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eMetakaolin (MK) %\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eGGBS %\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eWaste Rubber (WR) %\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eFine Aggregates (FA) %\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eM10G20R0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e70\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e100\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eM10G20R2.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e70\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e2.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e97.5\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eM10G20R5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e70\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e95\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eM10G20R7.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e70\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e7.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e92.5\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eM10G20R10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e70\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e90\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003eNote: where CC is Conventional concrete M is Metakaolin, G is GGBS and R is Waste fine rubber\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec14\" class=\"Section2\"\u003e \u003ch2\u003e4.3 \u0026lsquo;Mix Design\u0026rsquo;\u003c/h2\u003e \u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e indicates that the concrete mix designs were M25 grade and that the respective proportions for each mix group were assigned according to the above. The design was done according to the provisions of IS 10262:2019 [\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e], thereby ensuring the standard requirements for quality and performance were attained by the mix. The design quantities of the various materials, namely, cement, aggregates, metakaolin, GGBS, and waste rubber, were estimated and are given in Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e. A uniform \u0026lsquo;water-cement ratio (W/C) of 0.45 was maintained\u0026rsquo;throughout all the mixes to ensure proper hydration and workability.\u003c/p\u003e \u003cp\u003e\u0026lsquo;All mixes were prepared by manual mixing on a clean flat surface\u0026rsquo;with non-absorptive properties so that there would be no interference from the substrate. The dry materials, namely cement and aggregates, were first mixed homogeneously until a uniform dry blend was obtained. Water was added after the dry aggregates were uniformly mixed to arrive at a uniform concrete mixture based on each mix's calculated water content. After that, the concrete was then carefully cast into the moulds for cube, cylinder, and beam sample casting.\u003c/p\u003e \u003cp\u003eConcrete was compacted for the filling of the moulds to eliminate any air pockets, thereby ensuring a strong structure. \u0026lsquo;The moulds were kept undisturbed for 24 hours so as to allow the concrete to set initially. After this duration, the moulds were very carefully removed, and the specimens were\u0026rsquo;submerged in curing water tanks for the appropriate durations in order to attain the desired strength. The curing was done based on the recommendations and guidelines to allow adequate hydration and \u0026lsquo;strength development of the concrete.\u0026rsquo;\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eMix proportions\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"8\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMix\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCement (Kg/m3)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eFA (Kg/m3)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eCA (Kg/m3)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eWaste rubber (Kg/m3)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eGGBS (Kg/m3)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eMetakaolin (Kg/m3)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003eWater (Kg/m3)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e440\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e640.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1126\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e198\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eM10G20R0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e308\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e640.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1126\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e88\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e44\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e198\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eM10G20R2.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e308\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e624.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1126\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e16.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e88\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e44\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e198\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eM10G20R5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e308\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e608\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1126\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e32.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e88\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e44\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e198\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eM10G20R7.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e308\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e592.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1126\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e48.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e88\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e44\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e198\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eM10G20R10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e308\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e576\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1126\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e64\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e88\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e44\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e198\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"8\"\u003eNote: Where Fa refers to Fine aggregate, CA refers to Coarse aggregate, CC is Conventional concrete, M is Metakaolin, G is GGBS and R is Waste fine rubber\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec15\" class=\"Section2\"\u003e \u003ch2\u003e4.4 Fresh properties of concrete\u003c/h2\u003e \u003cp\u003eWorkability was determined by slump test (IS 1199:1959) [\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e] which measures the\u0026ensp;consistency and fluidity of concrete. The mix was then layered into a\u0026ensp;slump cone, compacted \u0026lsquo;with 25 strokes of a tamping rod\u0026rsquo; per layer, the cone lifted to measure the height of the slump. High slump values signify\u0026ensp;better flowability suitable for its application in reinforced structures, where both segregation and bleeding of fresh concrete are to be avoided, whereas lower slump values indicate increased cohesion and comparatively less segregation. A bulk density equipment, which was also utilized to layer and compact the concrete in a similar manner, was employed to measure density. The compactness and strength of the mix were ascertained by calculating the bulk density, which was derived from the weight differential between the full and empty apparatus.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec16\" class=\"Section2\"\u003e \u003ch2\u003e4.5 Hardened Properties of concrete\u003c/h2\u003e \u003cp\u003eCompressive\u0026ensp;strength, split tensile strength and flexural strength tests of hardened solid. In this process, three different Universal Testing Machine (UTM) standards (IS 516:1999) [\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e] were used to assess the flexural strength of beams (100 mm \u0026times; 100 mm \u0026times; 500 mm), split tensile strength of cylindrical specimens (150 mm diameter \u0026times; 300 mm height), and compressive strength of cube samples (150 mm\u0026ensp;\u0026times; 150 mm \u0026times; 150 mm) respectively. The demoulding was done after 24 h and placed in a tank for curing under water for 7, 14\u0026ensp;and 28 days. Each curing period\u0026ensp;had three specimens prepared to guarantee sound and reproducible results. The main purpose of the tests was the\u0026ensp;study of the time-dependent strength development of concrete.\u003c/p\u003e \u003c/div\u003e"},{"header":"5. ‘RESULTS AND DISCUSSION’","content":"\u003cdiv id=\"Sec18\" class=\"Section2\"\u003e \u003ch2\u003e5.1 \u0026lsquo;Fresh Properties of Concrete\u0026rsquo;\u003c/h2\u003e \u003cdiv id=\"Sec19\" class=\"Section3\"\u003e \u003ch2\u003e5.1.1 \u0026lsquo;Slump Test\u0026rsquo;\u003c/h2\u003e \u003cp\u003e \u003cdiv class=\"BlockQuote\"\u003e \u003cp\u003eResults from both literature reviews and experimental work coincidentally indicate that adding more rubber to concrete decreases its workability. Previous studies have also confirmed this trend: [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e] found that slump decreased from 48 cm in a control mix to 38 cm at 25% of rubber replacement. This is in the same manner as that reported with study by [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e] which showed a decline from 70 mm in ordinary concrete down to 50 mm with 20% replacement of rubber ash; similar results were reported by [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e] and [\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e]. Untreated rubber fibers reduced slump from 100 mm to 60 mm at 20% replacement, according to [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. However, the NaOH treatment slightly improved workability of the mixtures. This pattern was further reinforced by studies done by [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e], [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e], and [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. On his side, [\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e] found out that lightweight rubberized mortar always maintained a steady flowability, while [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e] proved that NaOH-treated rubber had better workability compared to untreated ones.\u0026lsquo;The slump test\u0026rsquo; shows a reduction in workability as the amount of waste latex in concrete mixtures that contain GGBS and metakaolin increases.\u003c/p\u003e \u003cp\u003eStraightforwardly, the slump test as shown In Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e5\u003c/span\u003e indicates that workability reduces progressively with increased waste rubber addition, as shown in previous studies. The slump for conventional concrete (CC) is 98 mm, after which a slump value of 80 mm was obtained at 10% rubber replacement, indicating a reduction of 18.37%. This reduction occurs because of the repulsion \u0026lsquo;of the water by the hydrophobic rubber particles\u0026rsquo;reducing fluidity. The initial mix reduced slightly to 95 mm at the first 10% metakaolin and 20% GGBS addition (M10G20R0), resulting in a 3.06% decrease due to microstructural refinement, but again increasing amounts of rubber decreased slump even more, namely: R2.5, R5, R7.5, and R10 show decreasing values of 6.12, 9.18, 14.29, 18.37 percent, respectively. The presence of metakaolin (M10) and GGBS (G20), which generally contribute to microstructure refinement and cementitious properties, were not sufficient to overcome the negative effect on workability. The trend is in line with previous studies that further confirm an adverse effect of rubber aggregates on slump.\u003c/p\u003e \u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec20\" class=\"Section3\"\u003e \u003ch2\u003e5.1.2 Density Test\u003c/h2\u003e \u003cp\u003eConcrete's density is determined by the type shape and the specific gravity of materials present in the concrete, as per the review of density from different researcher\u0026rsquo;s state that, Rubber, in fact, replaces natural aggregates and brings about a subsequent reduction of concrete density. However, untreated rubber significantly reduces densities [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e], [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e] and [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e] while pretreatment [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] and surface alteration [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e] mitigate the effects slightly. Larger rubber particles would bring out the greater effectiveness [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. However, to improve the density of packed material and reduce porosity offsetting density loss, GGBS, metakaolin, and polypropylene fibers were introduced [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e], [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e], [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. Few studies have shown that density reduces from 2,402 kg/m\u0026sup3; to 2,233 kg/m\u0026sup3; at a 20% replacement of rubber [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e] and 2,475 kg/m\u0026sup3; to 2,069 kg/m\u0026sup3; [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. From foam concrete, rubber replacement reduced the \u0026lsquo;density from 1,800 kg/m\u0026sup3; to 1,600 kg/m\u0026sup3;\u0026rsquo;[\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]. Rubberized concrete is lightweight, but adding admixtures and surface treatments ensures optimization of its properties.\u003c/p\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e6\u003c/span\u003e shows the difference on density of concrete prepared with different percentages substitution with waste rubber as well as mineral admixtures. Figure\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e5\u003c/span\u003e displays that as the percentage of waste rubber is increasing,\u0026rsquo; the density of rubberized concrete decreased. \u0026lsquo;It should be noted that waste rubber has a low specific gravity\u0026rsquo; (1.2), the Density of Conventional Concrete (CC) was observe to be 2490 kg/m\u003csup\u003e3\u003c/sup\u003e, whereas the addition of Metakaolin(10%) and GGBS(20%) by partial replacement to cement for concrete, the density was observed to be 2453.33 kg/m\u003csup\u003e3\u003c/sup\u003e, which was a slight reduction due the less specific gravity of Metakaolin (2.4) and GGBS (2.9) compared to cement(3.11).\u0026lsquo;Whereas the partial replacement of\u0026rsquo;waste rubber to fine aggregate by volume for 2.5, 5, 7.5 and 10 percent, the results show the reduction of 3.21, 6.29, 6.56 and 7.5 percent. Reductions in density could be credited to the partial replacement of standard materials with lighter alternative materials such as an aggregate of rubber, which is lightweight certainly.\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv id=\"Sec21\" class=\"Section2\"\u003e \u003ch2\u003e5.2 \u0026lsquo;Hardened properties of concrete\u0026rsquo;\u003c/h2\u003e \u003cdiv id=\"Sec22\" class=\"Section3\"\u003e \u003ch2\u003e5.2.1 \u0026lsquo;Compressive strength test\u0026rsquo;\u003c/h2\u003e \u003cp\u003eIn general, the poor link between rubber particles and the cement matrix causes the compressive property of rubberized concrete to diminish when waste rubber is added. [\u003cspan additionalcitationids=\"CR2 CR3\" citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e] all agree that adding more rubber lowers compressive strength. From studies, however, strength loss may be minimized through optimized mix design and incorporation of supplementary cementitious materials. [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] and [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e] were able to show that pre-treatment, sort of a chemical pre-treatment, of rubber fibers with NaOH, enhances bonding leading to strength improvements. Also, research by [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e] have shown that the incorporation of polypropylene fibers, silica fume, and waste glass powder improved the mechanical performance of rubberized concrete. It has also been found that the addition of metakaolin and GGBS enhances compressive strength through pozzolanic reaction and microstructure refinement [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e], [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e], [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eExperiments confirm these results. \u0026lsquo;The compressive strength of (CC) as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e7\u003c/span\u003e\u0026rsquo; was 20.04 MPa, 24.86 MPa, and 32.11 MPa at 7, 14, and 28 days, respectively. At 7 days, however, the strength of the samples in which metakaolin replaced 10% and GGBS replaced 20% of cement without waste rubber (M10G20R0) was less than that of the CC. On the contrary, this method was superior at 28 days, showing the long-term strength advantages of these mineral admixtures. As for the substitution of waste rubber fine aggregate at 2.5, 5, 7.5, and 10 percent. The findings indicated that the compressive strength gradually decreased. Nevertheless, the modified mixes gained strength over time, with the M10G20R0 mix, which contained no rubber, showing 8.8% greater strength than conventional concrete at 28 days. This is indicative of its long-term strength with the advantages of mineral admixtures.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe weak link between the WR and the concrete's cement paste is the primary source of the decrease in compressive strength. The strength was less affected by small dosage of rubber percentage than the higher percentage. The trend implies that on one hand, mineral admixtures provide improvements in long-term strength, while on the other hand, an increase in rubber content makes compressive strength suffer because rubber has lesser stiffness and bonding capabilities compared to conventional fine aggregates.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec23\" class=\"Section3\"\u003e \u003ch2\u003e5.2.2 Split Tensile Strength test\u003c/h2\u003e \u003cp\u003eThere are various studies on the impacts of rubber waste\u0026lsquo;on concrete split tensile strength,\u0026rsquo;Rubberized concrete possesses different split tensile strength depending on the type, size, percentage of rubber, and any additional materials. After\u0026lsquo;7 days and 28 days, foam concrete with 5% rubber\u0026rsquo;powder obtained a value of 1.86 and 1.97 MPa, respectively, as ascribed to the void filling, according to [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]. While the higher content of rubber led to the reduction in strength, it was satisfactory until 15% replacement, especially in treating the surface of rubber, say [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. According to [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e], the finer rubber particles brought more strength reduction, whereas [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e] indicated a controlled reduction using waste rubber ash. [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] concluded that silica fumes, waste glass powder, and rubber fiber treatments effectively mitigate losses; however, [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e] confirmed that rubberized concrete tensile strength is lower than normal concrete but still viable for pavements, crash barriers, and lightweight structures.\u003c/p\u003e \u003cp\u003eThis study's experimental findings have been verified like the above statement, as shown in the Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e8\u003c/span\u003e the \u0026lsquo;conventional concrete (CC) had a split tensile strength of 3.57\u0026rsquo; MPa at 28 days, while the M10G20R0 mix (consisting of 10% metakaolin and 20% GGBS without rubber) showed better performance than CC, a slight increase in strength. Nevertheless, greater rubber content warranted a steady fading of tensile strength; while the M10G20R2.5 mix dropped compared to CC by 18.76%, M10G20R5 showed a reduction of 31.65%. Further increases in rubber content worsened strength losses, with M10G20R7.5 exhibiting a 35.57% reduction and M10G20R10 a 38.10% reduction. Thus, these findings have shown that while rubberized concrete suffers from reduced split tensile strength, such reduction can still be minimized through optimized levels of replacement and the use of supplementary cementitious materials like metakaolin and GGBS for maintaining structural integrity.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e\u0026lsquo;The Tensile strength was analyzed for 28 days for different mixes.\u0026rsquo; The outcomes shows that the tensile strength gradually reduced as the inclusion of WR increases, but the incorporation of mineral admixtures and without WR shows an improve result. The decreased stiffness and decreased bonding efficiency of the rubber particles lead to a weakening of the concrete matrix and, thus, to the loss in its strength. Meanwhile, reasonable tensile capacity appears to be retained by the rubberized mixes, which probably implies some benefits from improved ductility and crack resistance for concrete applications.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec24\" class=\"Section3\"\u003e \u003ch2\u003e5.2.3 Flexural Strength Test\u003c/h2\u003e \u003cp\u003eAn actual study \u0026lsquo;on the effect of waste rubber on the flexural strength of concrete\u0026rsquo; has been conducted. [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e] investigated concrete blends with\u0026lsquo;rubber fiber and ash as partial fine aggregate\u0026rsquo;replacements and argued that not exceeding 10% replacement produced a strong mix suitable for pavements and crash barriers. Similarly, but on a different note, [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e] conducted studies using tire shreds at different percentages (2.5\u0026ndash;10%) to partially replace fine aggregate and have reported good results in flexural strength. [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e] \u0026lsquo;assessed \u0026lsquo;crumb rubber as a partial replacement of coarse\u0026rsquo; aggregates\u0026rsquo;without giving specific values for flexural strength. [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e] investigated \u0026lsquo;silica fumes and waste glass powder as\u0026rsquo; additives to crumb rubber concrete with an emphasis on the mechanics of the latter, particularly flexural strength. The literature mostly describes the reduction of flexural strength in rubber inclusions. [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e] \u0026lsquo;observed a decline in flexural strength with a rubber addition, which findings were also reported by [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. It was noted by noted [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e] that the inclusion of waste tire rubber reduced the flexural strength values, both in normal concrete and fly-ash concrete. According [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e], there was a considerable reduction in workability of foam concrete containing rubber powder, although no details on flexural strength were provided. It was reported that increasing rubber content further reduced flexural strength by [\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eQuite a few studies, however, have suggested mechanisms for the enhancement of flexural strength in rubberized concrete. There was a suggesting by [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e] for enhancement of flexural strength by addition of nano-silica and metakaolin. It was noted by [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e] that metakaolin enhanced the strength in GGBS ternary concrete over time, although lack of data on flexural strength was noted. Thus, the research indicates waste rubber in general reduces flexural strength, although the modifications can help to alter the effects.\u003c/p\u003e \u003cp\u003eThe experimental results were in agreement with these studies that show the effect of waste rubber on flexure. As shown in Fig.\u0026nbsp;9 standard concrete (CC) mix attained a 4.00 MPa flexural strength at 28 days. 10% \u0026lsquo;metakaolin and 20% ground granulated blast-furnace slag,\u0026rsquo;without rubber replacement, produced the highest strength of the M10G20R0 inclusion by 8.25%. But there was a slow drop in flexural strength as the proportion of waste rubber replacement rose. The M10G20R2.5 recorded the reduction of 10.5%, M10G20R5 was reduced by 14.5%, M10G20R7.5 recorded a 16.75% decrease, while the highest strength loss of 18.75% with the increasing percentage of rubber replacement was observed for M10G20R10 compared to CC.\u003c/p\u003e \u003cp\u003eConcrete's flexural strength steadily decreased as the concentration of rubber in the mixture increased. The use of rubber as a fine aggregate substitute resulted in a progressive decrease in flexural capacity, whereas the mix without rubber-maintained strength values greater than the control mix. \u0026lsquo;The reduction in strength\u0026rsquo; is primarily due to the lower stiffness and bonding efficiency of rubber aggregates, which impact the load transfer mechanism in the concrete matrix. Despite this reduction, rubberized concrete retains reasonable flexural strength, suggesting potential benefits in applications requiring enhanced toughness and crack resistance.\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"6. MICROSTRUCTURE AND SPECTROSCOPIC ANALYSIS OF RUBBERIZED CONCRETE","content":"\u003cdiv id=\"Sec26\" class=\"Section2\"\u003e \u003ch2\u003e6.1 \u0026lsquo;Scanning Electron Microscopy (SEM) Analysis\u0026rsquo;\u003c/h2\u003e\u003cp\u003eSEM analysis gives a comprehensive analysis of microstructural changes in concrete with varied levels of rubber content. M10G20R0 as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e10\u003c/span\u003e does not contain rubber but reflects the most dense and packed microstructure with very well-formed C-S-H gel and thus, higher porosity. Therefore, it achieves the highest in mechanical strength. The combination of metakaolin and GGBS increases pozzolanic action and refines pore structure, and durability is enhanced. At 2.5% rubber addition to M10G20R2.5, as shown in Fig.\u0026nbsp;11, the microstructure remains relatively dense, well distributed with hydration products, giving it the highest strength among other rubberized mixes. However, the SEM pictures reveal a weak bond at the rubber-cement interface which comes with microcracks and voids as potential stress concentration points.\u003c/p\u003e \u003cp\u003eThe higher the rubber content becomes, to 7.5%, the less dense and more extended-out space at M10G20R7.5 as Fig.\u0026nbsp;\u003cspan refid=\"Fig8\" class=\"InternalRef\"\u003e12\u003c/span\u003e shows. It is very porous and has an irregular-type microstructure, which can be observed with visible voids and weak interfacial bonding. Incomplete hydration is further corroborated by the presence of unreacted metakaolin and GGBS and enhanced by larger rubber particles with poor adhesion, resulting in low mechanical strength. It has significantly increased porosity and weakened zones around them that form a problem about the structure as a whole. M10G20R10, which has a full 10% rubber replacement, appears to show a more balanced behavior as seen in Fig.\u0026nbsp;13. The microstructure-involved voids and ITZ between rubber and cement exhibit poor adhesion; however, they benefit from the densification effects of both metakaolin and GGBS, which cause improvements in sulfate resistance and overall durability. The SEM images indicate that while increasing rubber reduces the continuity of the matrix and compressive strength, it enhances ductility and impact resistance.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec27\" class=\"Section2\"\u003e \u003ch2\u003e6.2 Energy-Dispersive X-Ray Spectroscopy (EDS)\u003c/h2\u003e \u003cp\u003eEDS has been elaborately used to analyze the elemental composition of rubberized concrete. The findings for the rubber replacement percentages of 0%, 2.5%, 7.5%, and 10% are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig9\" class=\"InternalRef\"\u003e14\u003c/span\u003e, which shows the maximum strength attained among the others, followed by the highest strength mid-strength and the lowest strength when combined with WR. Carbon, oxygen, sodium, potassium, calcium, silica, magnesium, aluminium, and sodium are significant components that are present in the spectroscopy findings and tables. Interestingly, the carbon content modifications greatly among M10G20R0 (0% rubber) and M10G20R10 (10% rubber), increasing from 2.89% by weight to 6.59% by weight. This rise in the carbon content indicates that the amount of rubber particles is suitable because rubber is basically a hydrocarbon polymers. Calcium and silicon concentrations, which are also necessary for cement hydration and C-S-H synthesis, show decreasing trends as rubber substitution rises. From 25.96% in M10G20R0 to 20.66% in M10G20R10, calcium has decreased, indicating more cementitious phase decreases that might be associated with possible declines in concrete mechanical strength. Again, silicon presents little variation, lending credence to another idea that higher rubber content dilutes the cementitious matrix. Oxygen content shows minor fluctuations among the different mixtures without any clear trend, perhaps due to interactions between rubber particles and the cement matrix. Magnesium, sodium, aluminium, and potassium are observed to behave closely to the same, suggesting that their influence on the concrete matrix is not much affected by rubber admixture. These variations in elemental composition elucidate their importance for rubber incorporation in microstructural properties. The decrease in calcium and silicon could indicate less\u0026lsquo;formation of C-S-H gel,\u0026rsquo; which might lead to lower mechanical strength. The increase in carbon content may affect density, porosity, and durability of concrete. From this study, it is evident that rubberized concrete has a sustainable nature dealing with waste products.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec28\" class=\"Section2\"\u003e \u003ch2\u003e6.3 \u0026lsquo;Fourier Transform Infrared Spectroscopy (FTIR) Analysis\u0026rsquo;\u003c/h2\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThrough FTIR spectra, the variation in chemical bonds for different series of rubberized concrete mixes is presented as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig10\" class=\"InternalRef\"\u003e15\u003c/span\u003e. Transmittance (%) plotted against the wavenumber (cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e) indicates key functional groups and how they affect the incorporation of rubber into the cementitious matrix. The control mix (M10G20R0) has the highest transmittance, that is, the least organic interference; increased rubber content brings about lower transmittance, signifying a larger presence of organic due to the rubber particles introduced into the mixture.\u003c/p\u003e \u003cp\u003eAs more rubber is added, absorption peaks associated with hydrocarbons and polymeric structures will continue to increase in intensity. The most important functional groups are found C-H bending (Aromatic/Alkene) at approximately\u0026thinsp;~\u0026thinsp;700 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, C-O stretching (Ethers, Esters, Alcohols) at ~\u0026thinsp;1100 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, C\u0026thinsp;=\u0026thinsp;C stretching (Aromatic/Alkenes) at ~\u0026thinsp;1600 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, C\u0026thinsp;=\u0026thinsp;O stretching (Carbonyl) at around 1750 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. These peaks are characteristic of compounds that are derived from rubber and that increases in intensity as rubber replacement increases. Further evidence of hydrocarbon presence through introduced organic bonds into concrete mixes by rubber is offered by C\u0026thinsp;\u0026equiv;\u0026thinsp;C and C\u0026thinsp;\u0026equiv;\u0026thinsp;N peaks (Alkynes/Nitriles) at approximately 2200 cm-1 and C-H stretching (Alkanes/Alkenes) at approximately 2900 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, respectively.\u003c/p\u003e \u003cp\u003eThe stronger intensity of C\u0026thinsp;=\u0026thinsp;O and C\u0026thinsp;=\u0026thinsp;C stretching in rubberized mixes indicates that the rubber component interacts with cement hydration products. However, higher contents of rubber may impede the hydration process and reduce \u0026lsquo;the interfacial bond between\u0026rsquo;cement paste and aggregates. There is an increase in O-H stretch (hydroxyl) at around ~\u0026thinsp;3400 cm⁻\u0026sup1; because of hydration-related interactions in rubberized mixes, suggesting that these mixes can retain some moisture or alter the product hydration. This retained moisture potentially could participate in delayed hydration reactions, which, in turn, could explain the strength recovery seen for some rubberized concrete mixes over time. C-H bending and stretching are indicative of the polymeric material present in the concrete mix from 700 to 3000 cm⁻\u0026sup1;. These compounds induce deformability but could also jeopardize the overall bonding efficiency, which results in a decreased tensile strength due to further rubber contents (especially beyond 5%). It is evident from the transmission spectrum that with increase in rubber percentages, the cement matrix is significantly altered at a structure level which might lead to changes in mechanical performances.\u003c/p\u003e \u003cp\u003eThe observed peak shifts are indicative that increasing rubber content would lead to handling of rubber-cement interactions through chemical rubber particle pretreatment or introduction of supplementary cementitious material. These ameliorations would strengthen\u0026rsquo;the interfacial bonding between rubber and cement\u0026rsquo;paste\u0026rsquo;and mitigate the corresponding strength losses due to excessive incorporation of rubber. FTIR analysis further brings to a conclusion that rubber replacement produces a significant change in the chemical composition and bond characteristics of the concrete matrix. While small amounts will not have much of a negative impact, larger amounts will bring in organic compounds that interfere with cement hydration and generally compromise structural integrity.\u003c/p\u003e \u003c/div\u003e"},{"header":"7. CONCLUSION","content":"\u003cp\u003eThe objectives envisioned for this work include the evaluation \u0026lsquo;of physical properties for cement, fine and coarse\u0026rsquo; aggregates, metakaolin, GGBS, and waste rubber, while\u0026lsquo;fresh and hardened properties\u0026rsquo;of M25 grade rubberized concrete with partial fine aggregates replacement by waste fine rubber are being studied at a 0.45 water cement ratio. Besides this, there will be an attempt to establish the optimum rubber replacement percentage for achieving desirable concrete strength and to study microstructural properties of concrete with waste rubbers and mineral admixtures.\u003c/p\u003e \u003cp\u003e \u003col style=\"list-style-type:lower-roman;\"\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003eUsing waste rubber as fine aggregate replacement will tend to minimize landfill waste generation and facilitate a circular economy; substituting part of the cement with GGBS and Metakaolin would go a long way in providing the necessary carbon footprint reduction to the already high CO\u003csub\u003e2\u003c/sub\u003e emissions from concrete production in the construction industry.\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003e\u0026lsquo;Sustainable Development Goals form part of SDG 9, 12 and 13. Where SDG 9 is Industry, Innovation \u0026amp; Infrastructure, SDG 12 is Responsible Consumption \u0026amp; Production promotes reuse of industrial waste, and finally, SDG 13, which is Climate Action, would reduce carbon emissions during the production of concrete-all in line with the United Nations Sustainable Development Goals (SDGs).\u0026rsquo;\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003eThe evaluation of cement, aggregates, metakaolin, GGBS, and waste rubber for sustainable concrete use was the primary focus of the study. The gradation for M-sand and coarse aggregate satisfied the grading requirements, and OPC 53 Grade has demonstrated high consistency and strength. Strength was eventually improved by the increased pozzolanic activity and microstructure caused by metakaolin and GGBS.\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003eThe slump value decreased by 18.37% at 10% rubber replacement due to the hydrophobic nature of rubber, reducing workability. Density also dropped by 7.5% compared to conventional concrete.\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003eAt 28 days, compressive strength increased by 8.8% for the mix containing 10% metakaolin and 20% GGBS with 0% rubber (M10G20R0), but it started to decline with the addition of rubber, falling by 11.8\u0026ndash;30.5% as a result of 10% replacement. Due to rubber, split tensile strength also increased by 2.8% for M10G20R0, but dropped by 18.76\u0026ndash;38.10%. Flexural strength saw an increase of 8.25%, while rubber replacement yielded a decrease of 10.5\u0026ndash;18.75%.\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003eAn optimal balance was achieved at 2.5% rubber replacement, meeting the M25 strength grade, while higher replacements caused significant strength reductions.\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003cspan\u003e \u003cli\u003e \u003cp\u003eMicrostructural analyses disclosed modification of the internal structure of concrete by the incorporation of waste rubber and mineral admixtures. Metakaolin and GGBS enhanced hydration and densified the matrix while increasing rubber content imparted more porosity and weaker interfacial bonding, which contributed to lesser strength. Optimal mix at 2.5% rubber replacement gave a balance between microstructural integrity and strength.\u003c/p\u003e \u003c/li\u003e \u003c/span\u003e \u003c/ol\u003e \u003c/p\u003e"},{"header":"8. FUTURE SCOPE","content":"\u003cp\u003eTo enhance the performance of rubberized concrete, improving bond strength is crucial. This can be achieved through chemical or mechanical pre-treatment of rubber particles, such as NaOH treatment, to enhance adhesion with the cement matrix. Further durability studies should be conducted focusing on water absorption, shrinkage, and resistance to freeze-thaw cycles. Moreover, conducting experiments with higher percentages of waste rubber will help determine the maximum feasible replacement level while maintaining acceptable strength and durability. Lastly, the feasibility of rubberized concrete in lightweight structural components and impact-resistant applications should be explored to expand its potential use in sustainable construction.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e \u003ch2\u003eFunds\u003c/h2\u003e \u003cp\u003eThis study was conducted without the support of any particular funds from public, private, or nonprofit funding organizations. All costs incurred for the experimental work and analysis were covered by the author.\u003c/p\u003e \u003c/p\u003e\u003cp\u003e \u003ch2\u003eConflict of Interest\u003c/h2\u003e \u003cp\u003eThe authors declare that there are no financial or personal relationships that could be construed as a conflict of interest in connection with the work submitted.\u003c/p\u003e \u003c/p\u003e \u003cp\u003e \u003cstrong\u003eConsent for Publication\u003c/strong\u003e \u003cp\u003eAll authors read and approved the final manuscript. They endorse its submission for publication in the designated journal. The writers certify that the work has never been published before and has not been submitted for publication anywhere else.\u003c/p\u003e \u003c/p\u003e\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eFreddy Joans Marboh conducted the study, carried out experimental work, conducted the literature review, analyzed the data, and wrote the manuscript. Narasimha Murthy K N contributed in terms of supervision, technical inputs, and critical revisions throughout the research process, ensuring the accuracy and integrity of the study. Both authors read and approved the final version of the manuscript.\u003c/p\u003e\u003ch2\u003eData availability\u003c/h2\u003e \u003cp\u003eSuch datasets as generated and analyzed during the course of this study can be made available, on request, and subject to reasonable conditions, from the corresponding author. Supplementary materials or any other information required by the inquirer for replication or follow-up research can be made available upon request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eLi Y, Zhang S, Wang R \u0026amp; Dang F. (2019). Potential use of waste tire rubber as aggregate in cement concrete\u0026ndash;A comprehensive review. Construction and Building Materials, 225, 1183-1201. \u003c/li\u003e\n\u003cli\u003eHabib A, Yildirim U \u0026amp; Eren O. (2020). Mechanical and dynamic properties of high-strength concrete with well-graded coarse and fine tire rubber. Construction and Building Materials, 246, 118502. \u003c/li\u003e\n\u003cli\u003eMeng X, Chi Y, Jiang Q, Liu R, Wu K \u0026amp; Li, S. (2019). Experimental investigation on the flexural behavior of pervious concrete beams reinforced with geogrids. Construction and Building Materials, 215, 275-284. \u003c/li\u003e\n\u003cli\u003eGupta T, Siddique S, Sharma R K \u0026amp; Chaudhary, S. (2021). Investigating mechanical properties and durability of concrete containing recycled rubber ash and fibers. Journal of Material Cycles and Waste Management, 23, 1048-1057. \u003c/li\u003e\n\u003cli\u003eRashid K, Yazdanbakhsh A \u0026amp; Rehman M. U. (2019). Sustainable selection of the concrete incorporating recycled tire aggregate to be used as a medium to low-strength material. Journal of Cleaner Production, 224, 396-410. \u003c/li\u003e\n\u003cli\u003eHiremath P, Jayakesh K, Rai R, Raghavendra N S \u0026amp; Yaragal S. (2019). Experimental investigation on utilization of waste shredded rubber tire as a replacement to fine aggregate in concrete. In Sustainable Construction and Building Materials: Select Proceedings of ICSCBM 2018 (pp. 561-569). Springer Singapore. \u003c/li\u003e\n\u003cli\u003ePutri E, Evir H P, Agista G A \u0026amp; Juliafad, E. (2023). Experimental Investigation on the Use of Crumb Rubber as Partial Replacement of Coarse Aggregate in Concrete Incorporating Cement Replacement Materials. GEOMATE Journal, 25(111), 246-253. \u003c/li\u003e\n\u003cli\u003eSingh G, Tiwary K, Singh S, Kumar R, Chohan J S, Sharma S \u0026amp; Deifalla A F. (2022). Incorporation of silica fumes and waste glass powder on concrete properties containing crumb rubber as a partial replacement of fine aggregates. Sustainability, 14(21), 14453. \u003c/li\u003e\n\u003cli\u003eAgrawal D, Waghe U, Ansari K, Dighade R, Amran M, Qader D N \u0026amp; Fediuk R. (2023). Experimental effect of pre-treatment of rubber fibers on mechanical properties of rubberized concrete. Journal of materials research and technology, 23, 791-807. \u003c/li\u003e\n\u003cli\u003eKarimi Pour, Mohajeri Z \u0026amp; Noroozinejad Farsangi E. (2022). Impact of polypropylene fibers on the mechanical and durability characteristics of rubber tire fine aggregate concrete. Materials, 15(22), 8043. \u003c/li\u003e\n\u003cli\u003eBadawi M, Ahmed A G, Eldamaty T A \u0026amp; Helal M. (2023). Properties of Recycled Concrete Utilizing Waste Rubber. Engineering, Technology \u0026amp; Applied Science Research, 13(4), 11451\u0026ndash;11458. \u003c/li\u003e\n\u003cli\u003eAbdelmonem A, El-Feky M S, Nasr E S \u0026amp; Kohail M (2019). Performance of High-Strength Concrete Containing Recycled Rubber. Construction and Building Materials, 227, 116660. \u003c/li\u003e\n\u003cli\u003eKumar R \u0026amp; Dev N. (2021). Mechanical and Microstructural Properties of Rubberized Concrete After Surface Modification of Waste Tire Rubber Crumb. Published by King Fahd University of Petroleum \u0026amp; Minerals \u003c/li\u003e\n\u003cli\u003eAbbas S, Fatima A, Kazmi S, Munir M J, Ali S \u0026amp; Rizvi M A. (2022). Effect of particle sizes and dosages of rubber waste on the mechanical properties of rubberized concrete composite. Applied Sciences, 12(17), 8460. \u003c/li\u003e\n\u003cli\u003eVignesh R \u0026amp; Abdul Rahim A. (2022). Mechanical and Microstructural Properties of Quaternary Binder System Containing OPC-GGBS-Metakaolin-Lime. Materials Today: Proceedings. \u003c/li\u003e\n\u003cli\u003eAl-Oran A, Safiee N A \u0026amp; Nasir N A. (2019). Fresh and Hardened Properties of Self-Compacting Concrete Using Metakaolin and GGBS as Cement Replacement. European Journal of Environmental and Civil Engineering. \u003c/li\u003e\n\u003cli\u003eNikkhah H, Tavakoli H R \u0026amp; Fallah N. (2023). Experimental investigation of the effects of using waste rubber ash on mechanical properties of plain concrete. International Journal of Engineering, Transactions C: Aspects, 36(3), 450-456. \u003c/li\u003e\n\u003cli\u003eKumar D C \u0026amp; Vasanthi P. (2022). Effect of coarse and fine GGBS in mechanical properties of concrete. Materials Today: Proceedings, 68, 1594\u0026ndash;1598. \u003c/li\u003e\n\u003cli\u003eElavarasan S, Priya A K, Ajai N, Akash S, Annie T J \u0026amp; Bhuvana G. (2020). Experimental study on partial replacement of cement by metakaolin and GGBS. Materials Today: Proceedings. \u003c/li\u003e\n\u003cli\u003eKadhim A A \u0026amp; Al-Mutairee H M K. (2020). An experimental study on the behavior of sustainable rubberized concrete mixes. Civil Engineering Journal. \u003c/li\u003e\n\u003cli\u003eAhmad J, Zhou Z, Majdi A, Alqurashi \u0026amp; Deifalla A F. (2022). Overview of concrete performance made with waste rubber tires: A step toward sustainable concrete. Materials, 15(16), 5518. \u003c/li\u003e\n\u003cli\u003eGupta T, Chaudhary S, \u0026amp; Sharma R K. (2014). Assessment of mechanical and durability properties of concrete containing waste rubber tire as fine aggregate. Construction and Building Materials, 73, 562\u0026ndash;574.\u003c/li\u003e\n\u003cli\u003eChalangaran N, Farzampour A \u0026amp; Paslar N. (2020). Nano silica and metakaolin effects on the behavior of concrete containing rubber crumbs. Civil Engineering, 1(3), 264\u0026ndash;274. \u003c/li\u003e\n\u003cli\u003eAppana P M, Mohammed B, Abdulkadir I, Ali M \u0026amp; Liew M S. (2022). Mechanical, microstructural, and drying shrinkage properties of NaOH-pretreated crumb rubber concrete: RSM-based modeling and optimization. Materials, 15(7), 2588. \u003c/li\u003e\n\u003cli\u003eMhaya A M, Abidin A, Sarbini N \u0026amp; Ismail M. (2019). Role of crumb tyre aggregates in rubberised concrete contained granulated blast-furnace slag. IOP Conference Series: Earth and Environmental Science, 220(1), 012029. \u003c/li\u003e\n\u003cli\u003eFauzan Nur O F, Albarqi K, Melinda A. P \u0026amp; Jauhari Z A. (2021). The effect of waste tyre rubber on mechanical properties of normal concrete and fly ash concrete. International Journal of GEOMATE, 20(77), 55\u0026ndash;61. \u003c/li\u003e\n\u003cli\u003eAneel Manan, Pu Zhang, Wael Alattyih, Hani Alanazi, S.K. Elagan, and Jawad Ahmad. \u0026quot;Mechanical and Microstructural Characterization of Sustainable Concrete Containing Recycled Concrete and Waste Rubber Tire Fiber.\u0026quot; Materials Research Express, 2024, in press. \u003c/li\u003e\n\u003cli\u003eMehrani S A, Bhatti I. A, Bhatti N. B, Jhatial A \u0026amp; Lohar M. A. (2019). Utilization of rubber powder of waste tyres in foam concrete. Journal of Applied Engineering Sciences, 9(22), 87-90. https://doi.org/10.2478/jaes-2019-0011\u003c/li\u003e\n\u003cli\u003eNasir N. A. M. \u0026amp; McCarthy M. J. (2014). Effect of metakaolin on early strength of GGBS ternary concrete. Applied Mechanics and Materials, 584\u0026ndash;586, 1551\u0026ndash;1557. \u003c/li\u003e\n\u003cli\u003eAbdullah W. A, Muhammad M. A \u0026amp; Abdulkadir M. R. (2020). Experimental investigation of some mechanical properties of rubberized concrete with highest possible rubber content. Journal of University of Duhok, 23(2), 509-522. \u003c/li\u003e\n\u003cli\u003eIbrahim O. M. O \u0026amp; Tayeh B. A. (2020). Combined effect of lightweight fine aggregate and micro rubber ash on the properties of cement mortar. Advances in Concrete Construction, 10(6), 537\u0026ndash;546. \u003c/li\u003e\n\u003cli\u003eBanerjee S, Mandal A \u0026amp; Rooby J. (2019). Performance of modified rubber aggregate concrete with GGBS and silica. International Journal of Innovative Technology and Exploring Engineering, 9(2), 2438\u0026ndash;2442. \u003c/li\u003e\n\u003cli\u003eBureau of Indian Standards. (1988). IS 4031:1988 \u0026ndash; Methods of physical tests for hydraulic cement. New Delhi, India: Bureau of Indian Standards.\u003c/li\u003e\n\u003cli\u003eBureau of Indian Standards. (1963). IS 2386 (Part 3):1963 \u0026ndash; Methods of test for aggregates for concrete: Part 3 Specific gravity, density, voids, absorption and bulking. New Delhi, India: Bureau of Indian Standards.\u003c/li\u003e\n\u003cli\u003eBureau of Indian Standards. (2019). IS 10262:2019 \u0026ndash; Guidelines for concrete mix proportioning. New Delhi, India: Bureau of Indian Standards.\u003c/li\u003e\n\u003cli\u003eBureau of Indian Standards. (1959). IS 516: Method of tests for strength of concrete. Bureau of Indian Standards.\u003c/li\u003e\n\u003cli\u003eBureau of Indian Standards. (1959). IS 1199:1959 \u0026ndash; Methods of sampling and analysis of concrete. New Delhi, India: Bureau of Indian Standards.\u003c/li\u003e\n\u003cli\u003eASTM International. (n.d.). Standard test methods for specific gravity and absorption of fine aggregate (ASTM D854)\u003c/li\u003e\n\u003cli\u003eBureau of Indian Standards. (2016). IS 383:2016 \u0026ndash; Coarse and fine aggregate for concrete \u0026ndash; Specification (Third Revision). Bureau of Indian Standards.\u003c/li\u003e\n\u003cli\u003eASTM International. (2018). ASTM D1509-18: Standard test method for carbon black \u0026ndash; Heating loss. ASTM International.\u003c/li\u003e\n\u003cli\u003eBritish Standards Institution. (1992). BS 6699:1992 \u0026ndash; Specification for ground granulated blast-furnace slag for use with Portland cement. British Standards Institution.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Rubberized concrete, Mineral admixtures, Waste rubber, Sustainable concrete, Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR) Analysis","lastPublishedDoi":"10.21203/rs.3.rs-6264503/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6264503/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eWith the increasing demand for concrete, there are environmental concerns relating to the dwindling natural aggregates and high carbon footprint produced due to the cement industry. Current research, therefore, aims to determine if rubberized concretes can be made sustainable by \u0026lsquo;partial replacement of fine aggregates with waste\u0026rsquo; rubber along with 20% GGBS and 10% metakaolin for partial replacement of Portland cement. The experimental program intended to study the fresh and hardened properties, namely, slump, density, \u0026lsquo;compressive strength,\u0026rsquo; split tensile strength,\u0026rsquo; flexural strength,\u0026rsquo; microstructural and spectroscopic properties (SEM and FTIR). The results showed that slump decreases by 18.37% and density by 7.5% at 10% rubber replacement. While compressive strength improved by 8.8% with the addition of mineral admixtures and declined by 30.5% when 10% rubber was added. Likewise, split tensile and flexural strengths at 0% rubber showed improvements of 2.8% and 8.25%, respectively, while at 10% rubber showed reduction of 38.1% and 18.75%, respectively. In spite of these decrements in strength, microstructural analysis demonstrated that the GGBS and metakaolin enhanced the hydration process and densified the matrix, which mitigated strength losses. Thus, an optimum sustainability-structural balance was noted at 2.5% rubber replacement, thereby rendering rubberized concrete a promising eco-friendly alternative for construction uses.\u003c/p\u003e","manuscriptTitle":"Development of rubberized concrete with mineral admixtures for sustainable concrete","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-04-03 04:41:35","doi":"10.21203/rs.3.rs-6264503/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"dd7d8a27-5b1b-4e25-bf2c-7a6fa075ef85","owner":[],"postedDate":"April 3rd, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-04-13T08:53:32+00:00","versionOfRecord":[],"versionCreatedAt":"2025-04-03 04:41:35","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-6264503","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6264503","identity":"rs-6264503","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}