Influence of Adding Different Amounts of Super Plasticizers and Macro Polypropylene Fiber on the Mechanical Properties and Microstructure of Roller Compacted Concrete

Influence of Adding Different Amounts of Super Plasticizers and Macro Polypropylene Fiber on the Mechanical Properties and Microstructure of Roller Compacted 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 Influence of Adding Different Amounts of Super Plasticizers and Macro Polypropylene Fiber on the Mechanical Properties and Microstructure of Roller Compacted Concrete Mohammed Hazim Yaseen, Syed Fuad, Eethar Thanon Dawood, Megat Azmi This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6143187/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 Laboratory experiments were conducted to assess the influence of incorporating varying quantities of superplasticizers and Macro PP Fiber on the mechanical properties and microstructure of roller-compacted concrete. The investigation comprised nine concrete mixtures, including a baseline mixture (C1) representing conventional concrete without superplasticizers and fiber. Additionally, five mixtures (C2, C3, C4, C5, and C6) incorporated different concentrations of superplasticizers (0.7%, 1.0%, 1.5%, 2.0%, and 2.5% of the cement content). In comparison, the remaining three mixtures (C7, C8, and C9) included varying amounts of Macro PP fiber (1, 3, and 5 kg/m 3 of concrete, respectively). The findings reveal a direct correlation between the superplasticizer content and both compressive and tensile strengths Additionally, the results indicate that the inclusion of polypropylene fibers in roller-compacted concrete yielded satisfactory mechanical strength outcomes. The PP fibers were strategically positioned about the cracks, enhancing the overall durability and resilience of the concrete. Roller Compacted Concrete (RCC) Super Plasticizers Macro Polypropylene Fiber Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Introduction Roller compacted concrete derives its name from the distinctive casting and placing method, involving the use of robust vibratory rollers [1]. In recent decades, experts and researchers have endorsed the utilization of Roller Compacted Concrete Pavement (RCCP) due to its economic, operational, and environmental advantages [2]. In terms of both operational and economic considerations, Roller Compacted Concrete Pavement (RCCP) features a lower cement content compared to conventional concrete [3]. Furthermore, Roller Compacted Concrete Pavement (RCCP) eliminates the requirement for tie bars and steel reinforcement. [4], Moreover, on-site placement of Roller Compacted Concrete Pavement (RCCP) is straightforward and uncomplicated [5]. Moreover, Roller Compacted Concrete Pavement (RCCP) demands fewer maintenance efforts and can withstand heavy loads more rapidly, thanks to its ability to achieve early high compressive, flexural, and shear strengths [6]. Hence, it is deemed a fitting option for emergency situations [7]. Moreover, Roller Compacted Concrete Pavement (RCCP) necessitates minimal labor. [8]. Likewise, the environmental benefit stems from the diminished cement content, mitigating the demand for manufacturing and utilizing this environmentally impactful material. Significantly, it aids in alleviating issues arising from the heat-induced hydration of cement, leading to a reduction in both cement consumption and CO2 emissions during production [3, 4]. Roller Compacted Concrete Pavement (RCCP) has the flexibility to incorporate increased proportions of waste and natural materials, including fly ash, silica fume, and rice husk ash. These materials can serve as substitutes for fine aggregates or cement. [9]. Utilizing fly ash, for example, enhances both the fresh and hardened properties of the concrete while concurrently lowering its overall cost [10]. Moreover, it aids in identifying appropriate applications for the utilization of fly ash, a byproduct generated in significant quantities on a global scale [9]. Importance of the Research for International Studies The research on the influence of superplasticizers and Macro Polypropylene Fiber on roller-compacted concrete (RCC) holds significant relevance for international research in several ways: Global Construction Practices: Roller-compacted concrete is increasingly being adopted worldwide due to its economic and operational advantages. This study provides insights into enhancing the mechanical properties of RCC, which can be beneficial for countries looking to improve their construction materials and methods . Sustainability and Environmental Impact: The research highlights the potential for reducing cement content through the use of superplasticizers and fibers, which can lead to lower CO2 emissions during production. This aligns with global sustainability goals and the need for environmentally friendly construction practices, making it relevant for international audiences focused on sustainable development . Material Performance in Diverse Conditions: By examining the mechanical properties and microstructure of RCC under various conditions, the findings can inform international standards and practices. This is particularly important for regions with different environmental challenges, such as extreme weather or heavy load requirements . Innovation in Construction Materials: The incorporation of advanced materials like Macro PP Fiber represents a shift towards innovative solutions in concrete technology. This research can inspire further studies and applications in other countries, promoting the exchange of knowledge and techniques in the field of construction materials . Standardization and Guidelines: The findings can contribute to the development of international standards for RCC, particularly in terms of material composition and performance criteria. This can help unify practices across different countries, facilitating international collaboration in construction projects . In summary, this research not only addresses local construction challenges but also contributes to the global discourse on sustainable and efficient building practices, making it highly relevant for international research communities. Objective of the Study The study's primary objective is to investigate how varying quantities of superplasticizers and Macro Polypropylene (PP) Fiber affect the mechanical properties and microstructure of roller-compacted concrete (RCC). The specific goals of the study include: Assessment of Mechanical Properties: The study aims to evaluate the compressive and tensile strengths of RCC when different concentrations of superplasticizers (ranging from 0.7% to 2.5% of cement content) and varying amounts of Macro PP Fiber (1, 3, and 5 kg/m³) are incorporated into the concrete mixtures. This assessment helps understand the performance enhancements provided by these additives. Microstructural Analysis: Another objective is to analyze the microstructure of the concrete mixtures using techniques such as X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). This analysis aims to reveal how adding superplasticizers and fibers influences the internal structure of the concrete, which is crucial for understanding durability and resilience. Comparison with Conventional Concrete: The study includes a baseline mixture (C1) representing conventional concrete without additives. By comparing the performance of the modified mixtures (C2 to C9) against this baseline, the research seeks to quantify the improvements in mechanical properties and durability achieved through superplasticizers and Macro PP Fiber. Guidance for Future Applications: Ultimately, the findings aim to provide valuable insights and guidelines for the construction industry regarding the optimal use of superplasticizers and fibers in RCC, which can lead to enhanced material performance and longevity in various applications. In summary, the study's objectives are to enhance our understanding of how specific additives can improve the mechanical and microstructural properties of roller-compacted concrete, thereby contributing to more effective construction practices. Specific problem or gap addressed by the paper The paper addresses several specific problems and gaps in the field of roller-compacted concrete (RCC) research, particularly concerning the use of superplasticizers and Macro Polypropylene (PP) Fiber. The key issues identified include: Limited Understanding of Additive Effects: There is a gap in knowledge regarding how different amounts of superplasticizers and Macro PP Fiber influence the mechanical properties of RCC. The study aims to fill this gap by systematically investigating the effects of varying concentrations of these additives on compressive and tensile strengths, which are critical for the performance of concrete in construction applications. Need for Enhanced Durability: The research highlights the necessity for improved durability and resilience in concrete structures. By incorporating Macro PP Fiber, the study seeks to address the problem of crack formation and propagation, which can significantly affect the longevity of concrete structures. The findings indicate that the strategic placement of fibers can enhance the overall durability of RCC. Microstructural Insights: Another gap addressed is the limited microstructural analysis of RCC with additives. The study employs X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) to explore how the addition of superplasticizers and fibers affects the internal structure of concrete. This microstructural perspective is crucial for understanding the mechanisms behind the observed improvements in mechanical properties. In summary, the paper effectively addresses the gaps in understanding the effects of superplasticizers and Macro PP Fiber on the mechanical properties and microstructure of roller-compacted concrete, providing valuable insights for future research and practical applications in the construction industry. Reasons for choosing MPP-type plastic The study highlights several reasons for selecting Macro Polypropylene (MPP) Fiber as an additive in roller-compacted concrete (RCC). These reasons include: High Performance: MPP Fiber is characterized as a high-performance monofilament polypropylene fiber specifically designed to enhance the mechanical properties of concrete. Its unique composition effectively reduces plastic shrinkage cracking, a common issue in concrete applications. Alkali Resistance: The MPP Fiber exhibits excellent alkali resistance, making it suitable for use in concrete exposed to harsh environmental conditions. This property helps maintain the integrity of the concrete over time, contributing to its durability and longevity. Impermeability and Non-Corrosive Properties: MPP Fiber is impermeable and non-corrosive, so it does not react adversely with the concrete matrix. This characteristic is crucial for preventing deterioration and enhancing the overall performance of the concrete, especially in applications where moisture exposure is a concern. Superior Alternative to Steel Reinforcement: The study suggests that MPP Fiber is superior to traditional reinforcement methods, such as steel mesh. By incorporating MPP Fiber, the concrete can achieve improved mechanical properties without the complications associated with steel reinforcement, such as corrosion and the need for additional support structures. Enhanced Durability: The inclusion of MPP Fiber in RCC is shown to enhance the overall durability and mechanical properties of the concrete. The fibers are strategically positioned around cracks, which helps to improve the resilience of the concrete under stress and reduces the likelihood of crack propagation. In summary, the study's choice of MPP-type plastic is driven by its high performance, resistance to environmental factors, and ability to enhance the durability and mechanical properties of roller-compacted concrete, making it a valuable additive in modern concrete applications. Ensuring uniformity of MPP fibers in concrete mixtures Achieving uniformity of Macro Polypropylene (MPP) fibers in concrete mixtures is crucial for optimizing the mechanical properties and overall roller-compacted concrete (RCC) performance. Here are several strategies and considerations based on the study: Dosage Control: The dosage of MPP fibers should be carefully controlled. The study indicates that the typical dosage ranges from 1.0 to 5.0 kg/m³ of concrete. Maintaining this range helps balance fiber distribution and the mechanical properties of the concrete, as excessive fiber content can lead to reduced strength due to overcrowding. Pre-Mixing with Dry Ingredients: A common practice is to pre-mix the MPP fibers with the dry ingredients (cement and aggregates) before adding water. This method helps achieve a more uniform distribution of fibers throughout the mixture, as they are less likely to clump together when combined with the dry materials. Use of Superplasticizers: Incorporating superplasticizers in the mixture can improve the workability of the concrete, allowing for better fiber distribution. The study shows that different concentrations of superplasticizers were tested, which can enhance the flowability of the concrete and facilitate a more uniform mix. In conclusion, ensuring the uniformity of MPP fibers in concrete mixtures involves proper mixing techniques, dosage control, and the use of additives like superplasticizers. These practices contribute to the overall effectiveness of MPP fibers in enhancing the mechanical properties of roller-compacted concrete. Methodology of the Study The methodology employed in this study on roller-compacted concrete (RCC) involved a systematic approach to assess the influence of superplasticizers and Macro Polypropylene (MPP) fibers on the mechanical properties and microstructure of the concrete. Here are the key steps outlined in the methodology: · Two-Stage Experimental Process: · The study was conducted in two stages. The first stage involved preparing a reference mixture of RCC based on the ACI 211.3R guidelines, which served as a baseline for comparison. This reference mixture was designed to meet specific strength requirements. · Mixture Proportions: · The second stage focused on preparing various RCC mixtures by incorporating different amounts of superplasticizers and MPP fibers. The mixtures included a baseline (C1) without additives and several others (C2 to C6) with varying concentrations of superplasticizers (0.7%, 1.0%, 1.5%, 2.0%, and 2.5% of cement content) and additional mixtures (C7 to C9) with different amounts of MPP fibers (1, 3, and 5 kg/m³). · Material Selection: · Ordinary Portland Cement Type 1 (OPC) was used as the primary binder, with its physical and chemical properties assessed according to Iraqi specifications. The aggregates were selected to ensure they were well-graded and met the prescribed limits. · Determination of Optimum Moisture Content: · The study involved determining the Optimum Moisture Content (OMC) and Maximum Dry Density using ASTM D 1557. Various cement contents (ranging from 10% to 17% of the dry aggregates' mass) were tested to establish the OMC for each mixture. · Casting and Curing: · Four RCC mixtures were cast using the selected cement content of 14% and corresponding OMC. The mixtures were cured for 28 days, after which their compressive and flexural strengths were measured to evaluate performance. · Microstructural Analysis: · X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) analyses were conducted on both the reference mixture and the Green Roller Compacted Concrete (GRCC) samples after 28 days of curing to assess the microstructural characteristics . This comprehensive methodology allowed for a detailed investigation into how varying amounts of superplasticizers and MPP fibers affect the mechanical properties and microstructure of roller-compacted concrete, providing valuable insights into its performance and potential applications. Materials used: 1. Cement: In this study, Ordinary Portland cement Type 1 (OPC) was chosen as the primary cement. The physical and chemical attributes of the OPC utilized in this investigation were assessed in alignment with Iraqi specifications. [11]. The results are outlined in Tables (1) and (2) for convenient reference Table 1. Physical and mechanical properties of OPC Properties Test results Iraqi specification No.5/1984 limits Specific surface area (Blain’s method), m²/kg 263.6 ≥ 230 Soundness (Autoclave’s Method), % 0.14 < 0.8 Setting time (Vicat’s method) Initial setting, hr:min Final setting, hr:min 1:13 3:15 ≥ 45 min ≤ 10 hours Compressive strength 3 days, N/mm² 7 days, N/mm² 21 29 ≥ 15 ≥ 23 Table 2 . Chemical compositions of OPC used Oxide Composition (% by weight) Test result of cement used Limits of IQS : 5/1984 SiO 2 21.31 ----- Al 2 O 3 5.89 ----- Fe 2 O 3 2.67 ----- CaO 62.2 ----- MgO 3.62 ≤ 5% SO 3 2.6 ≤ 2.80 % (if C3A ≥ 5 %) Loss of ignition 1.59 ≤ 4% Insoluble residue 0.24 ≤ 0.15% Main Component C 3 S 40.388 ----- C 2 S 30.835 ----- C 3 A 11.09 ----- C 4 AF 8.12 ----- 2. Coarse aggregate In this investigation, gravel with a maximum aggregate size of 19 mm was employed, adhering to the specifications stipulated in the ACI 211 3R standard [12]. The sieve analysis outcomes for the gravel are detailed in Table (3) for clarity and ease of reference. Table 3 . Sieve analysis of the used coarse aggregate Sieve size (mm) Cumulative passing(%) Limits of ACI 211.3R , 25 100 100 19 93 82-100 12.5 84 72-93 9.5 74 66-85 3. Fine aggregate . In this study, fine natural sand obtained from the Kanhash region was utilized, meeting the specified criteria outlined in the ACI 211.3R standard. The sieve analysis results for this sand are presented in Table (4) for convenient reference Table 4 . Sieve analysis of the used fine aggregate Sieve size (mm) Cumulative passing (%) Limits of ACI 211.3R 4.75 54 51-69 2.36 38 38-56 1.18 29 28-46 0.6 22 18-36 0.3 17 11-27 0.15 7 6-18 0.075 2 2-8 4. Macro PP Fiber : Macro PP Fiber, a high-performance monofilament polypropylene macro fiber, is a synthetic material composed of 100% polypropylene fibers. It contains no reprocessed olefin materials and exhibits excellent alkali resistance, impermeability, and non-corrosive properties. The distinctive composition of Macro PP Fiber makes it a superior alternative to traditional reinforcement steel mesh, effectively reducing plastic shrinkage cracking and enhancing the durability and mechanical properties of cementitious mixes. Dosage: The dosage of Macro PP Fiber is contingent upon the application area and the desired properties of concrete mixes. The usual dosage falls within the range of 1.0 to 5.0 kg/m³ of concrete. The characteristics of the polypropylene fibers are illustrated in Table (5) and Figure (1) Table (5): Properties of glass fibers Fiber properties Quantity Color White Shape Monofilaments macro fiber Specific gravity 0.95 ± 0.05 Modulus of elasticity 3.4 - 4.0 GPa Tensile Strength ≥450 MPa Chemical Resistance Very high Electrical Conductivity Very low Melting point 160˚C Ignition point 580˚C Chloride content Nil Sulphate content Nil Alkali content Nil Acid & Alkali Resistance Strong 5. Super plasticizer : Hyperplast PC175, a high-performance superplasticizing admixture, is formulated with polycarboxylic polymers featuring extended chains. Specifically designed to enhance the efficiency of water content in concrete, it conforms to the standards for superplasticizers outlined in ASTM C 494 Types G and F and BS EN 934 Part 2: 2001. [13]. Table 6 and Figure 2 illustrate the key characteristics of the employed superplasticizers. Table 6: Properties of superplasticizers (Hyperplast PC175) Property Constitution Chloride content Aqueous solution of modified Polycarboxylate Density 1.08 ± 0.02Kg/lt pH Value 6 ± 1.0 Colour Yellowish liquid Dosage ( 0.40 - 2.50 ) liters per 100 kg of cementitious materials in the mix, including GGBFS, PFA or microsilica. 6. Water: All the concrete mixtures were prepared using tap water. Experimental work: This study involved a two-stage process. Initially, the first stage encompassed the preparation of a mixture proportion of Roller Compacted Concrete (RCC) based on ACI 211.3R guidelines, serving as the reference mixture. Subsequently, the second stage entailed the preparation of mixtures of Roller Compacted Concrete (RCC) by adding different amounts of superplasticiser and PP fiber The outcomes of the second stage were assessed by comparing them with the reference mixture. Below, we comprehensively explain the mix proportions, mixing procedure, sample preparation, curing methods, and test procedures employed in this study. The procedure for designating the mixture proportions of reference mixtures is as follows: 1. Select well-graded dry coarse and fine aggregates that fall within the prescribed limits of ACI 211.3R (2002) . 2. Determine the Optimum Moisture Content and Maximum Dry Density using ASTM D 1557. 3. Determine the Optimum moisture content and maximum dry density of roller-compacted concrete mixtures by casting various quantities of cement, ranging from 10% to 17% of the dry aggregates ‘mass. For each cement content, Four mixtures were cast , with varying water content ranging from 3% to 9% of the dry aggregate's weight, The Optimum Moisture Content (OMC) for cement contents of 10%, 13%, 14%, and 17% resulted in values of 6.23%, 6.86%, 7.1%, and 8.56% respectively. 4. Four roller-compacted concrete mixtures were cast using cement content from 10% to 17 corresponding optimum moisture content determined from stage 2, saving the water quantity for the mix. Each mixture's compressive strength and flexural strength were measured after 28 days. Based on the desired flexural strength range of 4-5 MPa, a cement content of 14% was selected, which was used for casting all the mixtures discussed in this paper. 5. a mixture proportion of 1: 3.23: 2.63, w/c= 0.47 was used as a reference mixture (C1) to meet the desired strength requirements. The procedure for designation the mixtures of Roller Compacted Concrete (RPC) is as follows: 1. Mixtures C1 comprise a reference mix representing normal concrete without superplasticizers and fiber. 2. Mixtures C2 to C6 were prepared by adding different levels of superplasticizers (0.7,1.0,1.5%, 2.0%, and 2.5% of the cement content) 3. Mixtures C7 to C9 were prepared by incorporating varying amounts of Macro PP fiber (1, 3, and 5 ) kg/m 3 of concrete. Table 7 presents the detailed composition of the mixtures used in this paper. Table 7: Mix proportion of reference and green mixtures Mix Cement Kg/m 3 Sand Kg/m 3 Gravel Kg/m 3 Water Kg/m 3 S.P Kg PP Kg/m 3 C1 327 1058 861 154 ------ ------ C2 327 1058 861 151.71 2.29 ------ C3 327 1058 861 150.73 3.27 ------ C4 327 1058 861 149.1 4.90 ------ C5 327 1058 861 147.46 6.54 ------ C6 327 1058 861 145.825 8.175 ------ C7 327 1058 861 154 ------ 1 C8 327 1058 861 154 ------ 3 C9 327 1058 861 154 ------ 5 Results and discussions In this study, the following experiments were performed: 1- Compressive strength: Table 8 and figure 3 display the results of RCC mixes compressive strength Table 8: Compressive strength test results Mixture 7-day compressive strength (MPa) 28day compressive strength (MPa) Percentage increase in 28day compressive strength C1 26 33.8 Reference mixture C2 28.8 37.5 11%* C3 30.5 39.9 18% C4 33.65 43.6 28.9% C5 32.8 42.7 26.3% C6 26.7 34.1 0.9% C7 27.2 39.4 16.5% C8 30.73 43.9 29.9% C9 24.82 31.55 -6% * Percentage increase in 28daycompressive strength= ((37.5 – 33.8 )/33.8) = 11% Table 8 and Figure 3 display the compressive strength values for Roller Compacted Concrete (RCC). Table 8 and Figure 3 indicate that the compressive strength of mixture C1 (without superplasticizer) was the lowest compared to the other mixtures. The highest strength was observed in mixture C4, which had 1.5% superplasticizer content among the five mixtures (C2 to C6). The compressive strength of the mixtures C2, C3,C4,C5 and C6 were increased by 11%, 18%,28.9%, 26.3% and 0.9% from that in mixture C1, respectively. Compressive strength increased 0.9% in mixture C6 compared to mixture C1. However, exceeding a superplasticizer percentage of 1.5% has an adverse impact on compressive strength. The 7-day compressive strength in C4 closely approached the standard compressive strength of the reference mixture C1 on the 28th day, as per Khayat and Libre [14]. This implies that Roller Compacted Concrete Pavement (RCCP) with a substantial volume of fly ash and superplasticizer content achieved early high compressive strength comparable to the later-age compressive strength in conventional RCCP. In summary, the addition of a superplasticizer led to a general increase in compressive strength across all ages considered in the experiment. In terms of compressive strength, as illustrated in Table 8, the influence of polypropylene fiber proves advantageous for concrete at 1 and 3 kg per m³ [15]. Topçu and Canbaz [16] demonstrated that fibers can mitigate crack formation and development, contributing to increased compressive strength. However, beyond 3 kg per m³, mixture C9 exhibits a decline in resistance. This reduction is attributed to an excess of fibers in the mixture, leading to a strength reduction. 2- Tensile strength : Table 9 and figure 4 displays the results of RCC mixes Splitting strength Table 9: Splitting strength test results Mixture 7day Splitting Tensile strength (MPa) 28day Splitting Tensile strength (MPa) Percentage increase in 28day Splitting Tensile strength C1 2.2 2.95 Reference Mixture C2 2.45 3.4 15.25% C3 3.1 3.95 33.9% C4 3.8 4.9 66.1% C5 3.8 4.9 66.1% C6 3.2 4.1 39% C7 2.4 3.15 6.8% C8 3.6 5.27 78.6% C9 3.3 4.6 55.9% Table 9 and Figure 4 depict the tensile strengths for various percentages of superplasticizers and macro polypropylene in RCC. RCC with elevated percentages of superplasticizers and macro polypropylene achieved high tensile strength, consistently within the typical range from the seventh day onwards. Mixture C4 exhibited the highest tensile strength (4.9 MPa), while the lowest was observed in mixture C1. The increase in tensile strength correlated with the rise in superplasticizer content, with mixtures C2, C3, C4, C5, and C6 experiencing increases of 15.25%, 33.9%, 66.1%, and 39% compared to mixture C1, respectively. Referring to Table 9 and Figure 4, which illustrates the changes in tensile strength through the splitting of different types of RCC, it is evident that the incorporation of polypropylene fiber in RCC with 1, 3, and 5 kg/m³ yields a positive impact on tensile strength by splitting. A notable increase of 78.6% is observed in C8 compared to C1. Moreover, a reduction in tensile strength by splitting is observed in C9 with 5 kg/m³ compared to C8, attributable to an excessive proportion of fibers in the mix. 3- .Micro-structural analysis : X-ray Diffraction analysis (XRD) and Scanning Electron Microscope (SEM) images were acquired from both the reference mixture and the Green Roller Compacted Concrete (GRCC) samples after a 28-day immersion in tap water. 3.1 X-ray diffraction analysis (XRD) : The outcomes of XRD analysis of the reference mixture and the roller compacted concrete RCC samples are shown in figure 5 , 6 and 7 respectively. The XRD analysis of the chosen RCC samples discloses comparable peaks with differing intensities for the primary phases, specifically quartz, calcite, and graphite 2H. Quartz, among these phases, predominates in the observed peaks. 3.2 Scanning electron microscopy (SEM) : Figure 8, 9 and 10 show the SEM morphology of reference mixture and the roller compacted concrete RCC respectively. Figures 8, 9, and 10 depict the formation of C-S-H, a byproduct of secondary hydration reactions. A minimal amount of calcium hydroxide Ca(OH)2 platelets can also be observed. Figure 10 also demonstrates that the mixture incorporating PP reveals the presence of fibers that seamlessly integrate into the cement matrix. CONCLUSION The test results indicate a positive correlation between the superplasticizer content and both compressive and tensile strengths. Across all ages of the mixtures, those containing superplasticizer consistently demonstrated higher strength compared to the control mixture (C1). Specifically, on day 28, the compressive strength increased by 11%, 18%, and 28.9% in mixtures with 0.7%, 1%, and 1.5% superplasticizer content, respectively, as opposed to the control mixture. Similarly, for tensile strength, these percentages were 15.25%, 33.9%, and 66.1%. The inclusion of polypropylene fibers in roller compacted concrete yielded satisfactory results in terms of mechanical strength. The PP fibers were positioned across the width of the crack, enhancing the resilience of the concrete. The visual examination of the concrete under an optical microscope reveals the clear positioning of polypropylene fibers within the matrix of the roller compacted concrete. It is evident that the cement paste effectively envelops the PP fibers. Comparison with Existing Literature The study on the influence of adding different amounts of superplasticizers and Macro Polypropylene (MPP) fibers on the mechanical properties and microstructure of roller-compacted concrete (RCC) provides valuable insights that can be compared with existing literature in the field. Here are some key points of comparison: · Mechanical Properties: · The findings of this study indicate a direct correlation between the superplasticizer content and the compressive and tensile strengths of the concrete mixtures. This aligns with existing literature suggesting that adding superplasticizers enhances the workability and strength of concrete by improving the dispersion of particles and reducing water content. · Fiber Reinforcement: · The study highlights that the inclusion of MPP fibers significantly contributes to the mechanical strength of RCC. This is consistent with previous research that has shown polypropylene fibers can improve the toughness and ductility of concrete, reducing crack propagation and enhancing durability. The strategic positioning of fibers around cracks, as noted in the study, is also supported by literature emphasizing the role of fibers in controlling crack formation and improving resilience. · Mix Design and Proportions: · The mix design used in this study, mainly the reference mixture with a cement content of 14% and a water-to-cement ratio of 0.47, is comparable to other studies exploring optimal mix designs for RCC. Many researchers advocate for similar proportions to achieve desired strength and durability outcomes, reinforcing the validity of the chosen mix design in this study. · Curing Methods: · While the study does not delve deeply into curing methods, existing literature emphasizes the importance of proper curing in achieving the desired mechanical properties of concrete. Curing affects hydration and strength development, and studies have shown that inadequate curing can lead to significant reductions in strength and durability, which is a critical consideration in the context of RCC . · Environmental and Economic Benefits: · The study mentions RCC's economic and operational advantages, which is supported by literature highlighting the lower cement content and simplified placement methods of RCC compared to conventional concrete. This aspect is increasingly relevant in discussions about sustainable construction practices and reducing the carbon footprint of concrete production. In summary, this study's findings are well-aligned with existing literature, reinforcing the understanding of how superplasticizers and MPP fibers can enhance the mechanical properties of roller-compacted concrete. The study contributes to the body of knowledge by providing empirical data that supports established theories and practices in concrete technology. Declarations Ethics declaration : Not applicable. Ethics, Consent to Participate, and Consent to Publish declarations: Not applicable. Consent to Publish declaration: Not applicable . Consent to Participate declaration: Not applicable Funding information: The authors state that no funding is involved. AUTHOR CONTRIBUTION: Acknowledgement that all authors accepted the responsibility for the manuscript's content and consented to its submission, reviewed all the results, and approved the final version. Author contribution: All authors have accepted responsibility for the entire content of this manuscript and consented to its submission to the journal, reviewed all the results, and approved the final version. S.F. S and M.H. designed the experiments and M.A carried them out. E.T prepared the manuscript with contributions from all co-authors. Acknowledgements : The authors thank Northern Technical University for generously providing all the facilities and essential scientific support required to complete this work. Conflict of interest : The authors state no conflict of interest. Data Availability Statement: All data generated or analyzed during this study are included in this published article. References S. D. Tayabji, T. W. Sherman, O. Keifer, A. Nanni, R. W. Piggott, D. Pittman, et al., "State-of-the-art report on roller-compacted concrete pavements," 1995. S. A. Ghahari, A. Mohammadi, and A. A. Ramezanianpour, "Performance assessment of natural pozzolan roller compacted concrete pavements," Case studies in construction materials, vol. 7, pp. 82-90, 2017. A. A. Ramezanianpour, A. Mohammadi, E. R. Dehkordi, and Q. B. Chenar, "Mechanical properties and durability of roller compacted concrete pavements in cold regions," Construction and Building Materials, vol. 146, pp. 260-266, 2017/08/15/ 2017. C. Chhorn, S. J. Hong, and S.-W. Lee, "A study on performance of roller-compacted concrete for pavement," Construction and Building Materials, vol. 153, pp. 535-543, 2017/10/30/ 2017. M. Pigeon and V. M. Malhotra, "Frost Resistance of Roller-Compacted High-Volume Fly Ash Concrete," Journal of Materials in Civil Engineering, vol. 7, pp. 208-211, 1995/11/01 1995. D. Harrington, F. Abdo, W. Adaska, C. V. Hazaree, H. Ceylan, and F. Bektas, "Guide for roller-compacted concrete pavements," 2010. ACI, "Roller-compacted Mass Concrete," 1999. D. W. Pittman and S. A. Ragan, "Drying shrinkage of roller-compacted concrete for pavement applications," Materials Journal, vol. 95, pp. 19-26, 1998. A. Yerramala and K. G. Babu, "Transport properties of high volume fly ash roller compacted concrete," Cement and Concrete composites, vol. 33, pp. 1057-1062, and 2011. D. P. Bentz and C. F. Ferraris, "Rheology and setting of high volume fly ash mixtures," Cement and Concrete Composites, vol. 32, pp. 265-270, 2010. Iraqi Organization Standardization and Quality Control, No. 5, “Standard Specifications for Portland Cement”, Baghdad, Iraq (2019). American Concrete Institute Committee ACI 211.3R, Guide for Selecting Proportions for No-Slump Concrete. ASTM C494/C494 M, "Standard Specifications for Chemical Admixtures for Concrete", The American Society for Testing and Materials, Philadelphia, (2015). K. H. Khayat and N. A. Libre, "Roller compacted concrete: field evaluation and mixture optimization," Missouri University of Science and Technology. Center for Transportation Infrastructure and Safety2014. P.S. Songa, S. Hwangb, B.C. Sheub “Strength properties of nylon- and polypropylene-fiber-reinforced concretes” Cement and Concrete Research 35 (2005) 1546–1550 June 2004 Topçu B, Canbaz M. Effect of different fibers on the mechanical properties of concrete containing fly ash. Constr Build Mater 2007; 21:1486–91. Additional Declarations No competing interests reported. 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Yaseen","email":"data:image/png;base64,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","orcid":"","institution":"Universiti Sains Malaysia","correspondingAuthor":true,"prefix":"","firstName":"Mohammed","middleName":"Hazim","lastName":"Yaseen","suffix":""},{"id":435204388,"identity":"266287b8-5889-4f39-866f-30bf7e1b0fda","order_by":1,"name":"Syed Fuad","email":"","orcid":"","institution":"Universiti Sains 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06:28:21","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6143187/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6143187/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":79785594,"identity":"888f3eb0-3db3-4bbd-897b-0f61433fc9b1","added_by":"auto","created_at":"2025-04-02 16:28:37","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":192009,"visible":true,"origin":"","legend":"\u003cp\u003eShape of polypropylene fibers\u003cstrong\u003e \u003c/strong\u003eused.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-6143187/v1/262d0189747b120f18efffbc.png"},{"id":79785027,"identity":"f5e401a3-6fa2-4efa-a013-70a6752e5200","added_by":"auto","created_at":"2025-04-02 16:12:37","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":139044,"visible":true,"origin":"","legend":"\u003cp\u003eShape of \u003cstrong\u003esuperplasticizers \u0026nbsp;\u003c/strong\u003eused\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-6143187/v1/e4e08bcc09c7453088ebf981.png"},{"id":79785025,"identity":"33aae074-b0fe-45a7-8a43-237ef9bcb23b","added_by":"auto","created_at":"2025-04-02 16:12:37","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":34509,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eCompressive Strength test results\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-6143187/v1/8430545b219fef4c4c096a81.png"},{"id":79785121,"identity":"619f0789-6a63-472e-b803-ff72b5ee5610","added_by":"auto","created_at":"2025-04-02 16:20:37","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":34903,"visible":true,"origin":"","legend":"\u003cp\u003eSplitting strength test results\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-6143187/v1/86420523b98ecdda06bb5669.png"},{"id":79785123,"identity":"273cb296-7cb6-40fd-b061-4c33e64b685f","added_by":"auto","created_at":"2025-04-02 16:20:37","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":356124,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eXRD pattern for Reference mixture C1at 28days .\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-6143187/v1/8fa903ffef0b9289350be80c.png"},{"id":79785032,"identity":"93ee4edd-2742-4604-bde8-059d9a8c6c47","added_by":"auto","created_at":"2025-04-02 16:12:37","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":307636,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eXRD pattern for mixture C4 at 28days .\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"6.png","url":"https://assets-eu.researchsquare.com/files/rs-6143187/v1/403895b2baf89053a02b0cdb.png"},{"id":79785036,"identity":"31c0f1f5-4c56-4317-a53a-d3c36ed57cbb","added_by":"auto","created_at":"2025-04-02 16:12:37","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":381734,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eXRD pattern for mixture C8 at 28days\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"7.png","url":"https://assets-eu.researchsquare.com/files/rs-6143187/v1/34eff765f75cb665b5bb078d.png"},{"id":79785040,"identity":"c96e8a3c-0ca5-4d00-93ac-3156554b734c","added_by":"auto","created_at":"2025-04-02 16:12:37","extension":"png","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":1013044,"visible":true,"origin":"","legend":"\u003cp\u003eSEM image of reference mixture C1\u003c/p\u003e","description":"","filename":"8.png","url":"https://assets-eu.researchsquare.com/files/rs-6143187/v1/63578bffdea79460ff683762.png"},{"id":79785056,"identity":"c12e4739-2989-43fd-aad7-13911fdad562","added_by":"auto","created_at":"2025-04-02 16:12:38","extension":"png","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":1026685,"visible":true,"origin":"","legend":"\u003cp\u003eSEM image of mixture C4\u003c/p\u003e","description":"","filename":"9.png","url":"https://assets-eu.researchsquare.com/files/rs-6143187/v1/9e2b7aa63c5703503b8809e7.png"},{"id":79785053,"identity":"75988a22-a390-4e16-b76a-ce1e705755a9","added_by":"auto","created_at":"2025-04-02 16:12:38","extension":"png","order_by":10,"title":"Figure 10","display":"","copyAsset":false,"role":"figure","size":741743,"visible":true,"origin":"","legend":"\u003cp\u003eSEM image of reference mixture C8\u003c/p\u003e","description":"","filename":"10.png","url":"https://assets-eu.researchsquare.com/files/rs-6143187/v1/7cfb18e35eac7ed3f9009f7c.png"},{"id":80534892,"identity":"0fd6e315-75bb-4108-bdb0-0b37d5d8edc7","added_by":"auto","created_at":"2025-04-14 11:47:06","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":5618521,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6143187/v1/dc7ea56d-07a6-4da7-8d2f-0446174c0f36.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Influence of Adding Different Amounts of Super Plasticizers and Macro Polypropylene Fiber on the Mechanical Properties and Microstructure of Roller Compacted Concrete","fulltext":[{"header":"Introduction","content":"\u003cp\u003eRoller compacted concrete derives its name from the distinctive casting and placing method, involving the use of robust vibratory rollers [1]. In recent decades, experts and researchers have endorsed the utilization of Roller Compacted Concrete Pavement (RCCP) due to its economic, operational, and environmental advantages [2]. In terms of both operational and economic considerations, Roller Compacted Concrete Pavement (RCCP) features a lower cement content compared to conventional concrete [3]. Furthermore, Roller Compacted Concrete Pavement (RCCP) eliminates the requirement for tie bars and steel reinforcement. [4], Moreover, on-site placement of Roller Compacted Concrete Pavement (RCCP) is straightforward and uncomplicated [5].\u003c/p\u003e\n\u003cp\u003eMoreover, Roller Compacted Concrete Pavement (RCCP) demands fewer maintenance efforts and can withstand heavy loads more rapidly, thanks to its ability to achieve early high compressive, flexural, and shear strengths [6]. Hence, it is deemed a fitting option for emergency situations [7]. Moreover, Roller Compacted Concrete Pavement (RCCP) necessitates minimal labor. [8].\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eLikewise, the environmental benefit stems from the diminished cement content, mitigating the demand for manufacturing and utilizing this environmentally impactful material. Significantly, it aids in alleviating issues arising from the heat-induced hydration of cement, leading to a reduction in both cement consumption and CO2 emissions during production [3, 4]. Roller Compacted Concrete Pavement (RCCP) has the flexibility to incorporate increased proportions of waste and natural materials, including fly ash, silica fume, and rice husk ash. These materials can serve as substitutes for fine aggregates or cement. [9]. Utilizing fly ash, for example, enhances both the fresh and hardened properties of the concrete while concurrently lowering its overall cost [10]. Moreover, it aids in identifying appropriate applications for the utilization of fly ash, a byproduct generated in significant quantities on a global scale [9].\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eImportance of the Research for International Studies\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe research on the influence of superplasticizers and Macro Polypropylene Fiber on roller-compacted concrete (RCC) holds significant relevance for international research in several ways:\u003c/p\u003e\n\u003cul type=\"disc\"\u003e\n \u003cli\u003eGlobal Construction Practices:\u003cul type=\"disc\"\u003e\n \u003cli\u003eRoller-compacted concrete is increasingly being adopted worldwide due to its economic and operational advantages. This study provides insights into enhancing the mechanical properties of RCC, which can be beneficial for countries looking to improve their construction materials and methods\u0026nbsp;.\u003c/li\u003e\n \u003c/ul\u003e\n \u003c/li\u003e\n \u003cli\u003eSustainability and Environmental Impact:\u003cul type=\"disc\"\u003e\n \u003cli\u003eThe research highlights the potential for reducing cement content through the use of superplasticizers and fibers, which can lead to lower CO2 emissions during production. This aligns with global sustainability goals and the need for environmentally friendly construction practices, making it relevant for international audiences focused on sustainable development\u0026nbsp;.\u003c/li\u003e\n \u003c/ul\u003e\n \u003c/li\u003e\n \u003cli\u003eMaterial Performance in Diverse Conditions:\u003cul type=\"disc\"\u003e\n \u003cli\u003eBy examining the mechanical properties and microstructure of RCC under various conditions, the findings can inform international standards and practices. This is particularly important for regions with different environmental challenges, such as extreme weather or heavy load requirements\u0026nbsp;.\u003c/li\u003e\n \u003c/ul\u003e\n \u003c/li\u003e\n \u003cli\u003eInnovation in Construction Materials:\u003cul type=\"disc\"\u003e\n \u003cli\u003eThe incorporation of advanced materials like Macro PP Fiber represents a shift towards innovative solutions in concrete technology. This research can inspire further studies and applications in other countries, promoting the exchange of knowledge and techniques in the field of construction materials\u0026nbsp;.\u003c/li\u003e\n \u003c/ul\u003e\n \u003c/li\u003e\n \u003cli\u003eStandardization and Guidelines:\u003cul type=\"disc\"\u003e\n \u003cli\u003eThe findings can contribute to the development of international standards for RCC, particularly in terms of material composition and performance criteria. This can help unify practices across different countries, facilitating international collaboration in construction projects\u0026nbsp;.\u003c/li\u003e\n \u003c/ul\u003e\n \u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eIn summary, this research not only addresses local construction challenges but also contributes to the global discourse on sustainable and efficient building practices, making it highly relevant for international research communities.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eObjective of the Study\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study's primary objective is to investigate how varying quantities of superplasticizers and Macro Polypropylene (PP) Fiber affect the mechanical properties and microstructure of roller-compacted concrete (RCC). The specific goals of the study include:\u003c/p\u003e\n\u003cul type=\"disc\"\u003e\n \u003cli\u003eAssessment of Mechanical Properties:\u003cul type=\"disc\"\u003e\n \u003cli\u003eThe study aims to evaluate the compressive and tensile strengths of RCC when different concentrations of superplasticizers (ranging from 0.7% to 2.5% of cement content) and varying amounts of Macro PP Fiber (1, 3, and 5 kg/m³) are incorporated into the concrete mixtures. This assessment helps understand the performance enhancements provided by these additives.\u003c/li\u003e\n \u003c/ul\u003e\n \u003c/li\u003e\n \u003cli\u003eMicrostructural Analysis:\u003cul type=\"disc\"\u003e\n \u003cli\u003eAnother objective is to analyze the microstructure of the concrete mixtures using techniques such as X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). This analysis aims to reveal how adding superplasticizers and fibers influences the internal structure of the concrete, which is crucial for understanding durability and resilience.\u003c/li\u003e\n \u003c/ul\u003e\n \u003c/li\u003e\n \u003cli\u003eComparison with Conventional Concrete:\u003cul type=\"disc\"\u003e\n \u003cli\u003eThe study includes a baseline mixture (C1) representing conventional concrete without additives. By comparing the performance of the modified mixtures (C2 to C9) against this baseline, the research seeks to quantify the improvements in mechanical properties and durability achieved through superplasticizers and Macro PP Fiber.\u003c/li\u003e\n \u003c/ul\u003e\n \u003c/li\u003e\n \u003cli\u003eGuidance for Future Applications:\u003cul type=\"disc\"\u003e\n \u003cli\u003eUltimately, the findings aim to provide valuable insights and guidelines for the construction industry regarding the optimal use of superplasticizers and fibers in RCC, which can lead to enhanced material performance and longevity in various applications.\u003c/li\u003e\n \u003c/ul\u003e\n \u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eIn summary, the study's objectives are to enhance our understanding of how specific additives can improve the mechanical and microstructural properties of roller-compacted concrete, thereby contributing to more effective construction practices.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eSpecific problem or gap addressed by the paper\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe paper addresses several specific problems and gaps in the field of roller-compacted concrete (RCC) research, particularly concerning the use of superplasticizers and Macro Polypropylene (PP) Fiber. The key issues identified include:\u003c/p\u003e\n\u003cul type=\"disc\"\u003e\n \u003cli\u003eLimited Understanding of Additive Effects:\u003cul type=\"disc\"\u003e\n \u003cli\u003eThere is a gap in knowledge regarding how different amounts of superplasticizers and Macro PP Fiber influence the mechanical properties of RCC. The study aims to fill this gap by systematically investigating the effects of varying concentrations of these additives on compressive and tensile strengths, which are critical for the performance of concrete in construction applications.\u003c/li\u003e\n \u003c/ul\u003e\n \u003c/li\u003e\n \u003cli\u003eNeed for Enhanced Durability:\u003cul type=\"disc\"\u003e\n \u003cli\u003eThe research highlights the necessity for improved durability and resilience in concrete structures. By incorporating Macro PP Fiber, the study seeks to address the problem of crack formation and propagation, which can significantly affect the longevity of concrete structures. The findings indicate that the strategic placement of fibers can enhance the overall durability of RCC.\u003c/li\u003e\n \u003c/ul\u003e\n \u003c/li\u003e\n \u003cli\u003eMicrostructural Insights:\u003cul type=\"disc\"\u003e\n \u003cli\u003eAnother gap addressed is the limited microstructural analysis of RCC with additives. The study employs X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) to explore how the addition of superplasticizers and fibers affects the internal structure of concrete. This microstructural perspective is crucial for understanding the mechanisms behind the observed improvements in mechanical properties.\u003c/li\u003e\n \u003c/ul\u003e\n \u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eIn summary, the paper effectively addresses the gaps in understanding the effects of superplasticizers and Macro PP Fiber on the mechanical properties and microstructure of roller-compacted concrete, providing valuable insights for future research and practical applications in the construction industry.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eReasons for choosing MPP-type plastic\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study highlights several reasons for selecting Macro Polypropylene (MPP) Fiber as an additive in roller-compacted concrete (RCC). These reasons include:\u003c/p\u003e\n\u003cul type=\"disc\"\u003e\n \u003cli\u003eHigh Performance:\u003cul type=\"disc\"\u003e\n \u003cli\u003eMPP Fiber is characterized as a high-performance monofilament polypropylene fiber specifically designed to enhance the mechanical properties of concrete. Its unique composition effectively reduces plastic shrinkage cracking, a common issue in concrete applications.\u003c/li\u003e\n \u003c/ul\u003e\n \u003c/li\u003e\n \u003cli\u003eAlkali Resistance:\u003cul type=\"disc\"\u003e\n \u003cli\u003eThe MPP Fiber exhibits excellent alkali resistance, making it suitable for use in concrete exposed to harsh environmental conditions. This property helps maintain the integrity of the concrete over time, contributing to its durability and longevity.\u003c/li\u003e\n \u003c/ul\u003e\n \u003c/li\u003e\n \u003cli\u003eImpermeability and Non-Corrosive Properties:\u003cul type=\"disc\"\u003e\n \u003cli\u003eMPP Fiber is impermeable and non-corrosive, so it does not react adversely with the concrete matrix. This characteristic is crucial for preventing deterioration and enhancing the overall performance of the concrete, especially in applications where moisture exposure is a concern.\u003c/li\u003e\n \u003c/ul\u003e\n \u003c/li\u003e\n \u003cli\u003eSuperior Alternative to Steel Reinforcement:\u003cul type=\"disc\"\u003e\n \u003cli\u003eThe study suggests that MPP Fiber is superior to traditional reinforcement methods, such as steel mesh. By incorporating MPP Fiber, the concrete can achieve improved mechanical properties without the complications associated with steel reinforcement, such as corrosion and the need for additional support structures.\u003c/li\u003e\n \u003c/ul\u003e\n \u003c/li\u003e\n \u003cli\u003eEnhanced Durability:\u003cul type=\"disc\"\u003e\n \u003cli\u003eThe inclusion of MPP Fiber in RCC is shown to enhance the overall durability and mechanical properties of the concrete. The fibers are strategically positioned around cracks, which helps to improve the resilience of the concrete under stress and reduces the likelihood of crack propagation.\u003c/li\u003e\n \u003c/ul\u003e\n \u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eIn summary, the study's choice of MPP-type plastic is driven by its high performance, resistance to environmental factors, and ability to enhance the durability and mechanical properties of roller-compacted concrete, making it a valuable additive in modern concrete applications.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEnsuring uniformity of MPP fibers in concrete mixtures\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAchieving uniformity of Macro Polypropylene (MPP) fibers in concrete mixtures is crucial for optimizing the mechanical properties and overall roller-compacted concrete (RCC) performance. Here are several strategies and considerations based on the study:\u003c/p\u003e\n\u003cul type=\"disc\"\u003e\n \u003cli\u003eDosage Control:\u003cul type=\"disc\"\u003e\n \u003cli\u003eThe dosage of MPP fibers should be carefully controlled. The study indicates that the typical dosage ranges from 1.0 to 5.0 kg/m³ of concrete. Maintaining this range helps balance fiber distribution and the mechanical properties of the concrete, as excessive fiber content can lead to reduced strength due to overcrowding.\u003c/li\u003e\n \u003c/ul\u003e\n \u003c/li\u003e\n \u003cli\u003ePre-Mixing with Dry Ingredients:\u003cul type=\"disc\"\u003e\n \u003cli\u003eA common practice is to pre-mix the MPP fibers with the dry ingredients (cement and aggregates) before adding water. This method helps achieve a more uniform distribution of fibers throughout the mixture, as they are less likely to clump together when combined with the dry materials.\u003c/li\u003e\n \u003c/ul\u003e\n \u003c/li\u003e\n \u003cli\u003eUse of Superplasticizers:\u003cul type=\"disc\"\u003e\n \u003cli\u003eIncorporating superplasticizers in the mixture can improve the workability of the concrete, allowing for better fiber distribution. The study shows that different concentrations of superplasticizers were tested, which can enhance the flowability of the concrete and facilitate a more uniform mix.\u003c/li\u003e\n \u003c/ul\u003e\n \u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003eIn conclusion, ensuring the uniformity of MPP fibers in concrete mixtures involves proper mixing techniques, dosage control, and the use of additives like superplasticizers. These practices contribute to the overall effectiveness of MPP fibers in enhancing the mechanical properties of roller-compacted concrete.\u003c/p\u003e"},{"header":"Methodology of the Study","content":"\u003cp\u003eThe methodology employed in this study on roller-compacted concrete (RCC) involved a systematic approach to assess the influence of superplasticizers and Macro Polypropylene (MPP) fibers on the mechanical properties and microstructure of the concrete. Here are the key steps outlined in the methodology:\u003c/p\u003e\n\u003cp\u003e\u0026middot; Two-Stage Experimental Process:\u003c/p\u003e\n\u003cp\u003e\u0026middot; The study was conducted in two stages. The first stage involved preparing a reference mixture of RCC based on the ACI 211.3R guidelines, which served as a baseline for comparison. This reference mixture was designed to meet specific strength requirements.\u003c/p\u003e\n\u003cp\u003e\u0026middot; Mixture Proportions:\u003c/p\u003e\n\u003cp\u003e\u0026middot; The second stage focused on preparing various RCC mixtures by incorporating different amounts of superplasticizers and MPP fibers. The mixtures included a baseline (C1) without additives and several others (C2 to C6) with varying concentrations of superplasticizers (0.7%, 1.0%, 1.5%, 2.0%, and 2.5% of cement content) and additional mixtures (C7 to C9) with different amounts of MPP fibers (1, 3, and 5 kg/m\u0026sup3;).\u003c/p\u003e\n\u003cp\u003e\u0026middot; Material Selection:\u003c/p\u003e\n\u003cp\u003e\u0026middot; Ordinary Portland Cement Type 1 (OPC) was used as the primary binder, with its physical and chemical properties assessed according to Iraqi specifications. The aggregates were selected to ensure they were well-graded and met the prescribed limits.\u003c/p\u003e\n\u003cp\u003e\u0026middot; Determination of Optimum Moisture Content:\u003c/p\u003e\n\u003cp\u003e\u0026middot; The study involved determining the Optimum Moisture Content (OMC) and Maximum Dry Density using ASTM D 1557. Various cement contents (ranging from 10% to 17% of the dry aggregates\u0026apos; mass) were tested to establish the OMC for each mixture.\u003c/p\u003e\n\u003cp\u003e\u0026middot; Casting and Curing:\u003c/p\u003e\n\u003cp\u003e\u0026middot; Four RCC mixtures were cast using the selected cement content of 14% and corresponding OMC. The mixtures were cured for 28 days, after which their compressive and flexural strengths were measured to evaluate performance.\u003c/p\u003e\n\u003cp\u003e\u0026middot; Microstructural Analysis:\u003c/p\u003e\n\u003cp\u003e\u0026middot; X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) analyses were conducted on both the reference mixture and the Green Roller Compacted Concrete (GRCC) samples after 28 days of curing to assess the microstructural characteristics\u0026nbsp;.\u003c/p\u003e\n\u003cp\u003eThis comprehensive methodology allowed for a detailed investigation into how varying amounts of superplasticizers and MPP fibers affect the mechanical properties and microstructure of roller-compacted concrete, providing valuable insights into its performance and potential applications.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cu\u003eMaterials used:\u003c/u\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e1. Cement: In this study, Ordinary Portland cement Type 1 (OPC) was chosen as the primary cement. The physical and chemical attributes of the OPC utilized in this investigation were assessed in alignment with Iraqi specifications. [11]. The results are outlined in Tables (1) and (2) for convenient reference\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 1.\u0026nbsp;\u003c/strong\u003ePhysical and mechanical properties of OPC\u003c/p\u003e\n\u003cdiv align=\"center\"\u003e\n \u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 253px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eProperties\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 105px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eTest results\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 177px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eIraqi specification No.5/1984 limits\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 253px;\"\u003e\n \u003cp\u003eSpecific surface area\u003c/p\u003e\n \u003cp\u003e(Blain\u0026rsquo;s method), m\u0026sup2;/kg\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 105px;\"\u003e\n \u003cp\u003e263.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 177px;\"\u003e\n \u003cp\u003e\u0026ge; 230\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 253px;\"\u003e\n \u003cp\u003eSoundness (Autoclave\u0026rsquo;s Method), %\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 105px;\"\u003e\n \u003cp\u003e0.14\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 177px;\"\u003e\n \u003cp\u003e\u0026lt; 0.8\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 253px;\"\u003e\n \u003cp\u003eSetting time (Vicat\u0026rsquo;s method)\u003c/p\u003e\n \u003cp\u003eInitial setting, hr:min\u003c/p\u003e\n \u003cp\u003eFinal setting, hr:min\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 105px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e1:13\u003c/p\u003e\n \u003cp\u003e3:15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 177px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u0026ge; 45 min\u003c/p\u003e\n \u003cp\u003e\u0026le; 10 hours\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 253px;\"\u003e\n \u003cp\u003eCompressive strength\u003c/p\u003e\n \u003cp\u003e3 days, N/mm\u0026sup2;\u003c/p\u003e\n \u003cp\u003e7 days, N/mm\u0026sup2;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 105px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e21\u003c/p\u003e\n \u003cp\u003e29\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 177px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u0026ge; 15\u003c/p\u003e\n \u003cp\u003e\u0026ge; 23\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003e\u003cstrong\u003eTable 2\u003c/strong\u003e. Chemical compositions of OPC used\u003c/p\u003e\n\u003cdiv align=\"center\"\u003e\n \u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 166px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eOxide Composition\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e(% by weight)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 189px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eTest result of\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003ecement used\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 182px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eLimits of\u003c/strong\u003e\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003eIQS\u003c/strong\u003e\u003cstrong\u003e\u0026nbsp;: 5/1984\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 166px;\"\u003e\n \u003cp\u003eSiO\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003e21.31\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 182px;\"\u003e\n \u003cp\u003e-----\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 166px;\"\u003e\n \u003cp\u003eAl\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003e5.89\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 182px;\"\u003e\n \u003cp\u003e-----\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 166px;\"\u003e\n \u003cp\u003eFe\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003e2.67\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 182px;\"\u003e\n \u003cp\u003e-----\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 166px;\"\u003e\n \u003cp\u003eCaO\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003e62.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 182px;\"\u003e\n \u003cp\u003e-----\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 166px;\"\u003e\n \u003cp\u003eMgO\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003e3.62\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 182px;\"\u003e\n \u003cp\u003e\u0026le; 5%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 166px;\"\u003e\n \u003cp\u003eSO\u003csub\u003e3\u003c/sub\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003e2.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 182px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026le; 2.80 % (if C3A \u0026ge; 5 %)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 166px;\"\u003e\n \u003cp\u003eLoss of ignition\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003e1.59\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 182px;\"\u003e\n \u003cp\u003e\u0026le; 4%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 166px;\"\u003e\n \u003cp\u003eInsoluble residue\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003e0.24\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 182px;\"\u003e\n \u003cp\u003e\u0026le; 0.15%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"3\" style=\"width: 537px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eMain Component\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 166px;\"\u003e\n \u003cp\u003eC\u003csub\u003e3\u003c/sub\u003eS\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003e40.388\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 182px;\"\u003e\n \u003cp\u003e-----\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 166px;\"\u003e\n \u003cp\u003eC\u003csub\u003e2\u003c/sub\u003eS\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003e30.835\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 182px;\"\u003e\n \u003cp\u003e-----\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 166px;\"\u003e\n \u003cp\u003eC\u003csub\u003e3\u003c/sub\u003eA\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003e11.09\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 182px;\"\u003e\n \u003cp\u003e-----\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 166px;\"\u003e\n \u003cp\u003eC\u003csub\u003e4\u003c/sub\u003eAF\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 189px;\"\u003e\n \u003cp\u003e8.12\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 182px;\"\u003e\n \u003cp\u003e-----\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003e\u003cstrong\u003e2. Coarse aggregate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn this investigation, gravel with a maximum aggregate size of 19 mm was employed, adhering to the specifications stipulated in the ACI 211 3R standard [12]. The sieve analysis outcomes for the gravel are detailed in Table (3) for clarity and ease of reference.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 3\u003c/strong\u003e. Sieve analysis of the used coarse aggregate\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 49px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 144px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eSieve size \u0026nbsp;(mm)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 186px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eCumulative passing(%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 186px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eLimits of\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eACI 211.3R\u003c/strong\u003e,\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 49px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 144px;\"\u003e\n \u003cp\u003e25\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003e100\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003e100\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 49px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 144px;\"\u003e\n \u003cp\u003e19\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003e93\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003e82-100\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 49px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 144px;\"\u003e\n \u003cp\u003e12.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003e84\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003e72-93\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 49px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 144px;\"\u003e\n \u003cp\u003e9.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003e74\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003e66-85\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003e3. Fine aggregate\u003c/strong\u003e\u003cem\u003e.\u0026nbsp;\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eIn this study, fine natural sand obtained from the Kanhash region was utilized, meeting the specified criteria outlined in the ACI 211.3R standard. The sieve analysis results for this sand are presented in Table (4) for convenient reference\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 4\u003c/strong\u003e. Sieve analysis of the used fine aggregate\u003c/p\u003e\n\u003cdiv align=\"center\"\u003e\n \u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 12px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 181px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eSieve size (mm)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 186px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eCumulative passing (%)\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 186px;\"\u003e\n \u003cp\u003e\u003cstrong\u003eLimits of\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eACI 211.3R\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 12px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 181px;\"\u003e\n \u003cp\u003e4.75\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003e54\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003e51-69\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 12px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 181px;\"\u003e\n \u003cp\u003e2.36\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003e38\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003e38-56\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 12px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 181px;\"\u003e\n \u003cp\u003e1.18\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003e29\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003e28-46\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 12px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 181px;\"\u003e\n \u003cp\u003e0.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003e22\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003e18-36\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 12px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 181px;\"\u003e\n \u003cp\u003e0.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003e17\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003e11-27\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 12px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 181px;\"\u003e\n \u003cp\u003e0.15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003e6-18\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 12px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 181px;\"\u003e\n \u003cp\u003e0.075\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 186px;\"\u003e\n \u003cp\u003e2-8\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003e\u003cstrong\u003e4.\u0026nbsp;\u003c/strong\u003e\u003cstrong\u003eMacro PP Fiber\u003c/strong\u003e:\u003c/p\u003e\n\u003cp\u003eMacro PP Fiber, a high-performance monofilament polypropylene macro fiber, is a synthetic material composed of 100% polypropylene fibers. It contains no reprocessed olefin materials and exhibits excellent alkali resistance, impermeability, and non-corrosive properties. The distinctive composition of Macro PP Fiber makes it a superior alternative to traditional reinforcement steel mesh, effectively reducing plastic shrinkage cracking and enhancing the durability and mechanical properties of cementitious mixes.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDosage:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe dosage of Macro PP Fiber is contingent upon the application area and the desired properties of concrete mixes. The usual dosage falls within the range of 1.0 to 5.0 kg/m\u0026sup3; of concrete. The characteristics of the polypropylene fibers are illustrated in Table (5) and Figure (1)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable (5):\u003c/strong\u003e Properties of glass fibers\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 274px;\"\u003e\n \u003cp\u003eFiber properties\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 293px;\"\u003e\n \u003cp\u003eQuantity\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 274px;\"\u003e\n \u003cp\u003eColor\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 293px;\"\u003e\n \u003cp\u003eWhite\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 274px;\"\u003e\n \u003cp\u003eShape\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 293px;\"\u003e\n \u003cp\u003eMonofilaments macro fiber\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 274px;\"\u003e\n \u003cp\u003eSpecific gravity\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 293px;\"\u003e\n \u003cp\u003e0.95 \u0026plusmn; 0.05\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 274px;\"\u003e\n \u003cp\u003eModulus of elasticity\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 293px;\"\u003e\n \u003cp\u003e3.4 - 4.0 GPa\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 274px;\"\u003e\n \u003cp\u003eTensile Strength\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 293px;\"\u003e\n \u003cp\u003e\u0026ge;450 MPa\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 274px;\"\u003e\n \u003cp\u003eChemical Resistance\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 293px;\"\u003e\n \u003cp\u003eVery high\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 274px;\"\u003e\n \u003cp\u003eElectrical Conductivity\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 293px;\"\u003e\n \u003cp\u003eVery low\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 274px;\"\u003e\n \u003cp\u003eMelting point\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 293px;\"\u003e\n \u003cp\u003e160˚C\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 274px;\"\u003e\n \u003cp\u003eIgnition point\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 293px;\"\u003e\n \u003cp\u003e580˚C\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 274px;\"\u003e\n \u003cp\u003eChloride content\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 293px;\"\u003e\n \u003cp\u003eNil\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 274px;\"\u003e\n \u003cp\u003eSulphate content\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 293px;\"\u003e\n \u003cp\u003eNil\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 274px;\"\u003e\n \u003cp\u003eAlkali content\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 293px;\"\u003e\n \u003cp\u003eNil\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 274px;\"\u003e\n \u003cp\u003eAcid \u0026amp; Alkali Resistance\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 293px;\"\u003e\n \u003cp\u003eStrong\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003e5. Super plasticizer :\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eHyperplast PC175, a high-performance superplasticizing admixture, is formulated with polycarboxylic polymers featuring extended chains. Specifically designed to enhance the efficiency of water content in concrete, it conforms to the standards for superplasticizers outlined in ASTM C 494 Types G and F and BS EN 934 Part 2: 2001. [13]. Table 6 and Figure 2 illustrate the key characteristics of the employed superplasticizers.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 6: Properties of \u0026nbsp;superplasticizers (Hyperplast PC175)\u003c/strong\u003e\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"576\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 145px;\"\u003e\n \u003cp\u003eProperty\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 431px;\"\u003e\n \u003cp\u003eConstitution\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 145px;\"\u003e\n \u003cp\u003eChloride content\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 431px;\"\u003e\n \u003cp\u003eAqueous solution of modified Polycarboxylate\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 145px;\"\u003e\n \u003cp\u003eDensity\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 431px;\"\u003e\n \u003cp\u003e1.08 \u0026plusmn; 0.02Kg/lt\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 145px;\"\u003e\n \u003cp\u003epH Value\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 431px;\"\u003e\n \u003cp\u003e6 \u0026plusmn; 1.0\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 145px;\"\u003e\n \u003cp\u003eColour\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 431px;\"\u003e\n \u003cp\u003eYellowish liquid\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 145px;\"\u003e\n \u003cp\u003eDosage\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 431px;\"\u003e\n \u003cp\u003e( 0.40 - 2.50 ) liters per 100 kg of cementitious materials in the mix, \u0026nbsp;including GGBFS, PFA or microsilica.\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u0026nbsp;\u003cstrong\u003e6. Water:\u0026nbsp;\u003c/strong\u003eAll the concrete mixtures were prepared using tap water.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cu\u003eExperimental work:\u003c/u\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study involved a two-stage process. Initially, the first stage encompassed the preparation of a mixture proportion of Roller Compacted Concrete (RCC) based on ACI 211.3R guidelines, serving as the reference mixture. Subsequently, the second stage entailed the preparation of mixtures of Roller Compacted Concrete (RCC) by adding different amounts of superplasticiser and PP fiber\u003c/p\u003e\n\u003cp\u003eThe outcomes of the second stage were assessed by comparing them with the reference mixture. \u0026nbsp;\u003cbr\u003e\u0026nbsp;Below, we comprehensively explain the mix proportions, mixing procedure, sample preparation, curing methods, and test procedures employed in this study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eThe procedure for designating the mixture proportions of reference mixtures is as follows:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e1. Select well-graded dry coarse and fine aggregates that fall within the prescribed limits of ACI 211.3R (2002) .\u003c/p\u003e\n\u003cp\u003e2. Determine the Optimum Moisture Content and Maximum Dry Density using ASTM D 1557.\u003c/p\u003e\n\u003cp\u003e3. Determine the Optimum moisture content and maximum dry density of roller-compacted concrete mixtures by casting various quantities of cement, ranging from 10% to 17% \u0026nbsp;of the dry aggregates \u0026lsquo;mass. For each cement content, Four mixtures were cast , with varying water content ranging from \u0026nbsp;3% to 9% \u0026nbsp; of the dry aggregate\u0026apos;s weight, The Optimum Moisture Content (OMC) for cement contents of 10%, 13%, 14%, and 17% resulted in values of 6.23%, 6.86%, 7.1%, and 8.56% respectively.\u003c/p\u003e\n\u003cp\u003e4. Four roller-compacted concrete mixtures were cast using cement content from 10% to 17 corresponding optimum moisture content determined from stage 2, saving the water quantity for the mix. Each mixture\u0026apos;s compressive strength and flexural strength were measured after 28 days. Based on the desired flexural strength range of 4-5 MPa, a cement content of 14% was selected, which was used for casting all the mixtures discussed in this paper.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e5. a mixture proportion of 1: 3.23: 2.63, w/c= 0.47 was used as a reference mixture (C1) to meet the desired strength requirements.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eThe procedure for designation \u0026nbsp;the mixtures of Roller Compacted Concrete (RPC) is as follows:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1.\u0026nbsp; \u0026nbsp;\u003c/strong\u003eMixtures C1\u0026nbsp;comprise a reference mix representing normal concrete without superplasticizers and fiber.\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2. \u0026nbsp;\u0026nbsp;\u003c/strong\u003eMixtures C2 to C6 were prepared by adding different levels of superplasticizers (0.7,1.0,1.5%, 2.0%, and 2.5% of the cement content)\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3. \u0026nbsp;\u003c/strong\u003eMixtures C7 to C9 were prepared by\u0026nbsp;incorporating varying amounts of Macro PP fiber (1, 3, and 5 ) kg/m\u003cstrong\u003e\u003csup\u003e3\u003c/sup\u003e\u003c/strong\u003e of concrete.\u003c/p\u003e\n\u003cp\u003eTable 7 presents the detailed composition of the mixtures\u0026nbsp;used in this paper.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 7:\u003c/strong\u003e Mix proportion of \u0026nbsp;reference and green mixtures\u0026nbsp;\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 80px;\"\u003e\n \u003cp\u003eMix\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 80px;\"\u003e\n \u003cp\u003eCement\u003c/p\u003e\n \u003cp\u003eKg/m\u003csup\u003e3\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 80px;\"\u003e\n \u003cp\u003eSand Kg/m\u003csup\u003e3\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 80px;\"\u003e\n \u003cp\u003eGravel Kg/m\u003csup\u003e3\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 80px;\"\u003e\n \u003cp\u003eWater Kg/m\u003csup\u003e3\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 80px;\"\u003e\n \u003cp\u003eS.P\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;Kg\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 80px;\"\u003e\n \u003cp\u003ePP\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;Kg/m\u003csup\u003e3\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 80px;\"\u003e\n \u003cp\u003eC1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 80px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e327\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 80px;\"\u003e\n \u003cp\u003e1058\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 80px;\"\u003e\n \u003cp\u003e861\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 80px;\"\u003e\n \u003cp\u003e154\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 80px;\"\u003e\n \u003cp\u003e------\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 80px;\"\u003e\n \u003cp\u003e------\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 80px;\"\u003e\n \u003cp\u003eC2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e327\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 80px;\"\u003e\n \u003cp\u003e1058\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 80px;\"\u003e\n \u003cp\u003e861\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e151.71\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 80px;\"\u003e\n \u003cp\u003e2.29\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e------\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 80px;\"\u003e\n \u003cp\u003eC3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e327\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 80px;\"\u003e\n \u003cp\u003e1058\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 80px;\"\u003e\n \u003cp\u003e861\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e150.73\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 80px;\"\u003e\n \u003cp\u003e3.27\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e------\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003eC4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e327\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 80px;\"\u003e\n \u003cp\u003e1058\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 80px;\"\u003e\n \u003cp\u003e861\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e149.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 80px;\"\u003e\n \u003cp\u003e4.90\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e------\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003eC5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e327\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 80px;\"\u003e\n \u003cp\u003e1058\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 80px;\"\u003e\n \u003cp\u003e861\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e147.46\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 80px;\"\u003e\n \u003cp\u003e6.54\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e------\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003eC6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e327\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 80px;\"\u003e\n \u003cp\u003e1058\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 80px;\"\u003e\n \u003cp\u003e861\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e145.825\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e8.175\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e------\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003eC7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e327\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 80px;\"\u003e\n \u003cp\u003e1058\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 80px;\"\u003e\n \u003cp\u003e861\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e154\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e------\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 80px;\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003eC8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e327\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 80px;\"\u003e\n \u003cp\u003e1058\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 80px;\"\u003e\n \u003cp\u003e861\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e154\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e------\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 80px;\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003eC9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e327\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 80px;\"\u003e\n \u003cp\u003e1058\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 80px;\"\u003e\n \u003cp\u003e861\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e154\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e------\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 80px;\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e"},{"header":"Results and discussions","content":"\u003cp\u003eIn this study, the following experiments were performed:\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e1- \u0026nbsp;\u003c/strong\u003e\u003cstrong\u003e\u003cu\u003eCompressive strength:\u0026nbsp;\u003c/u\u003e\u003c/strong\u003eTable 8 and figure 3 display the results of\u0026nbsp;RCC mixes\u0026nbsp;compressive strength\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 8:\u003c/strong\u003e Compressive strength test results\u003c/p\u003e\n\u003cdiv align=\"center\"\u003e\n \u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 79px;\"\u003e\n \u003cp\u003eMixture\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 133px;\"\u003e\n \u003cp\u003e7-day compressive strength (MPa)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 137px;\"\u003e\n \u003cp\u003e28day\u003c/p\u003e\n \u003cp\u003ecompressive strength (MPa)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 155px;\"\u003e\n \u003cp\u003e\u003cstrong\u003ePercentage increase in\u0026nbsp;\u003c/strong\u003e28day\u003c/p\u003e\n \u003cp\u003ecompressive strength\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 79px;\"\u003e\n \u003cp\u003eC1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 133px;\"\u003e\n \u003cp\u003e26\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 137px;\"\u003e\n \u003cp\u003e33.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 155px;\"\u003e\n \u003cp\u003eReference mixture\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 79px;\"\u003e\n \u003cp\u003eC2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 133px;\"\u003e\n \u003cp\u003e28.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 137px;\"\u003e\n \u003cp\u003e37.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 155px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e11%*\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 79px;\"\u003e\n \u003cp\u003eC3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 133px;\"\u003e\n \u003cp\u003e30.5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 137px;\"\u003e\n \u003cp\u003e39.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 155px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e18%\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 79px;\"\u003e\n \u003cp\u003eC4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 133px;\"\u003e\n \u003cp\u003e33.65\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 137px;\"\u003e\n \u003cp\u003e43.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 155px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e28.9%\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 79px;\"\u003e\n \u003cp\u003eC5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 133px;\"\u003e\n \u003cp\u003e32.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 137px;\"\u003e\n \u003cp\u003e42.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 155px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e26.3%\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 79px;\"\u003e\n \u003cp\u003eC6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 133px;\"\u003e\n \u003cp\u003e26.7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 137px;\"\u003e\n \u003cp\u003e34.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 155px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e0.9%\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 79px;\"\u003e\n \u003cp\u003eC7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 133px;\"\u003e\n \u003cp\u003e27.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 137px;\"\u003e\n \u003cp\u003e39.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 155px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e16.5%\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 79px;\"\u003e\n \u003cp\u003eC8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 133px;\"\u003e\n \u003cp\u003e30.73\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 137px;\"\u003e\n \u003cp\u003e43.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 155px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e29.9%\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 79px;\"\u003e\n \u003cp\u003eC9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 133px;\"\u003e\n \u003cp\u003e24.82\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 137px;\"\u003e\n \u003cp\u003e31.55\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 155px;\"\u003e\n \u003cp\u003e\u003cstrong\u003e-6%\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003e\u003cstrong\u003e*\u0026nbsp;\u003c/strong\u003ePercentage increase in 28daycompressive strength= ((37.5 \u0026ndash; 33.8 )/33.8) = 11%\u003c/p\u003e\n\u003cp\u003eTable 8 and Figure 3 display the compressive strength values for Roller Compacted Concrete (RCC). Table 8 and Figure 3 indicate that the compressive strength of mixture C1 (without superplasticizer) was the lowest compared to the other mixtures. The highest strength was observed in mixture C4, which had 1.5% superplasticizer content among the five mixtures (C2 to C6).\u003c/p\u003e\n\u003cp\u003eThe compressive strength of the mixtures C2, C3,C4,C5 and C6 were increased by 11%, 18%,28.9%, 26.3% and 0.9% from that in mixture C1, respectively.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eCompressive strength increased 0.9% in mixture C6 compared to mixture C1. However, exceeding a superplasticizer percentage of 1.5% has an adverse impact on compressive strength.\u003c/p\u003e\n\u003cp\u003eThe 7-day compressive strength in C4 closely approached the standard compressive strength of the reference mixture C1 on the 28th day, as per Khayat and Libre [14]. This implies that Roller Compacted Concrete Pavement (RCCP) with a substantial volume of fly ash and superplasticizer content achieved early high compressive strength comparable to the later-age compressive strength in conventional RCCP.\u003c/p\u003e\n\u003cp\u003eIn summary, the addition of a superplasticizer led to a general increase in compressive strength across all ages considered in the experiment.\u003c/p\u003e\n\u003cp\u003eIn terms of compressive strength, as illustrated in Table 8, the influence of polypropylene fiber proves advantageous for concrete at 1 and 3 kg per m\u0026sup3; [15]. Top\u0026ccedil;u and Canbaz [16] demonstrated that fibers can mitigate crack formation and development, contributing to increased compressive strength. However, beyond 3 kg per m\u0026sup3;, mixture C9 exhibits a decline in resistance. This reduction is attributed to an excess of fibers in the mixture, leading to a strength reduction.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e2- \u0026nbsp;\u003c/strong\u003e\u003cstrong\u003e\u003cu\u003eTensile strength\u003c/u\u003e\u003c/strong\u003e\u003cstrong\u003e:\u003c/strong\u003e Table 9 and figure 4 displays the results of RCC mixes Splitting strength\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 9:\u003c/strong\u003e Splitting strength test results\u003c/p\u003e\n\u003cdiv align=\"center\"\u003e\n \u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 79px;\"\u003e\n \u003cp\u003eMixture\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 155px;\"\u003e\n \u003cp\u003e7day\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eSplitting Tensile \u0026nbsp;strength (MPa)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 162px;\"\u003e\n \u003cp\u003e28day\u003c/p\u003e\n \u003cp\u003eSplitting Tensile \u0026nbsp;strength (MPa)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003ePercentage increase in 28day\u003c/p\u003e\n \u003cp\u003eSplitting Tensile \u0026nbsp;strength\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 79px;\"\u003e\n \u003cp\u003eC1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 155px;\"\u003e\n \u003cp\u003e2.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 162px;\"\u003e\n \u003cp\u003e2.95\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 156px;\"\u003e\n \u003cp\u003eReference Mixture\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 79px;\"\u003e\n \u003cp\u003eC2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 155px;\"\u003e\n \u003cp\u003e2.45\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 162px;\"\u003e\n \u003cp\u003e3.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 156px;\"\u003e\n \u003cp\u003e15.25%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 79px;\"\u003e\n \u003cp\u003eC3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 155px;\"\u003e\n \u003cp\u003e3.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 162px;\"\u003e\n \u003cp\u003e3.95\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 156px;\"\u003e\n \u003cp\u003e33.9%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 79px;\"\u003e\n \u003cp\u003eC4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 155px;\"\u003e\n \u003cp\u003e3.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 162px;\"\u003e\n \u003cp\u003e4.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 156px;\"\u003e\n \u003cp\u003e66.1%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 79px;\"\u003e\n \u003cp\u003eC5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 155px;\"\u003e\n \u003cp\u003e3.8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 162px;\"\u003e\n \u003cp\u003e4.9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 156px;\"\u003e\n \u003cp\u003e66.1%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 79px;\"\u003e\n \u003cp\u003eC6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 155px;\"\u003e\n \u003cp\u003e3.2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 162px;\"\u003e\n \u003cp\u003e4.1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 156px;\"\u003e\n \u003cp\u003e39%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 79px;\"\u003e\n \u003cp\u003eC7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 155px;\"\u003e\n \u003cp\u003e2.4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 162px;\"\u003e\n \u003cp\u003e3.15\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 156px;\"\u003e\n \u003cp\u003e6.8%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 79px;\"\u003e\n \u003cp\u003eC8\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 155px;\"\u003e\n \u003cp\u003e3.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 162px;\"\u003e\n \u003cp\u003e5.27\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 156px;\"\u003e\n \u003cp\u003e78.6%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd style=\"width: 79px;\"\u003e\n \u003cp\u003eC9\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 155px;\"\u003e\n \u003cp\u003e3.3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd style=\"width: 162px;\"\u003e\n \u003cp\u003e4.6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 156px;\"\u003e\n \u003cp\u003e55.9%\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003eTable 9 and Figure 4 depict the tensile strengths for various percentages of superplasticizers and macro polypropylene in RCC. RCC with elevated percentages of superplasticizers and macro polypropylene achieved high tensile strength, consistently within the typical range from the seventh day onwards. Mixture C4 exhibited the highest tensile strength (4.9 MPa), while the lowest was observed in mixture C1. The increase in tensile strength correlated with the rise in superplasticizer content, with mixtures C2, C3, C4, C5, and C6 experiencing increases of 15.25%, 33.9%, 66.1%, and 39% compared to mixture C1, respectively.\u003c/p\u003e\n\u003cp\u003eReferring to Table 9 and Figure 4, which illustrates the changes in tensile strength through the splitting of different types of RCC, it is evident that the incorporation of polypropylene fiber in RCC with 1, 3, and 5 kg/m\u0026sup3; yields a positive impact on tensile strength by splitting. A notable increase of 78.6% is observed in C8 compared to C1.\u003c/p\u003e\n\u003cp\u003eMoreover, a reduction in tensile strength by splitting is observed in C9 with 5 kg/m\u0026sup3; compared to C8, attributable to an excessive proportion of fibers in the mix.\u003c/p\u003e\n\u003cp\u003e3- \u003cstrong\u003e\u003cu\u003e.Micro-structural analysis :\u003c/u\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eX-ray Diffraction analysis (XRD) and Scanning Electron Microscope (SEM) images were acquired from both the reference mixture and the Green Roller Compacted Concrete (GRCC) samples after a 28-day immersion in tap water.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cu\u003e3.1 X-ray diffraction analysis (XRD)\u003c/u\u003e\u003c/strong\u003e\u003cstrong\u003e:\u003c/strong\u003e The outcomes of XRD analysis of the reference mixture and the roller compacted concrete RCC samples are shown in figure 5 , 6 and 7 respectively.\u003c/p\u003e\n\u003cp\u003eThe XRD analysis of the chosen RCC samples discloses comparable peaks with differing intensities for the primary phases, specifically quartz, calcite, and graphite 2H. Quartz, among these phases, predominates in the observed peaks.\u003c/p\u003e\n\u003cp\u003e\u003cu\u003e3.2 \u003cstrong\u003eScanning electron microscopy (SEM)\u003c/strong\u003e:\u003c/u\u003e Figure 8, 9 and 10 show the SEM morphology of reference mixture and the \u0026nbsp;roller compacted concrete RCC respectively.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eFigures 8, 9, and 10 depict the formation of C-S-H, a byproduct of secondary hydration reactions. A minimal amount of calcium hydroxide Ca(OH)2 platelets can also be observed.\u003c/p\u003e\n\u003cp\u003eFigure 10 also demonstrates that the mixture incorporating PP reveals the presence of fibers that seamlessly integrate into the cement matrix.\u003c/p\u003e"},{"header":"CONCLUSION","content":"\u003cp\u003eThe test results indicate a positive correlation between the superplasticizer content and both compressive and tensile strengths. Across all ages of the mixtures, those containing superplasticizer consistently demonstrated higher strength compared to the control mixture (C1). Specifically, on day 28, the compressive strength increased by 11%, 18%, and 28.9% in mixtures with 0.7%, 1%, and 1.5% superplasticizer content, respectively, as opposed to the control mixture. Similarly, for tensile strength, these percentages were 15.25%, 33.9%, and 66.1%.\u003c/p\u003e\n\u003cp\u003eThe inclusion of polypropylene fibers in roller compacted concrete yielded satisfactory results in terms of mechanical strength. The PP fibers were positioned across the width of the crack, enhancing the resilience of the concrete.\u003c/p\u003e\n\u003cp\u003eThe visual examination of the concrete under an optical microscope reveals the clear positioning of polypropylene fibers within the matrix of the roller compacted concrete. It is evident that the cement paste effectively envelops the PP fibers.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eComparison with Existing Literature\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe study on the influence of adding different amounts of superplasticizers and Macro Polypropylene (MPP) fibers on the mechanical properties and microstructure of roller-compacted concrete (RCC) provides valuable insights that can be compared with existing literature in the field. Here are some key points of comparison:\u003c/p\u003e\n\u003cp\u003e· Mechanical Properties:\u003c/p\u003e\n\u003cp\u003e· The findings of this study indicate a direct correlation between the superplasticizer content and the compressive and tensile strengths of the concrete mixtures. This aligns with existing literature suggesting that adding superplasticizers enhances the workability and strength of concrete by improving the dispersion of particles and reducing water content.\u003c/p\u003e\n\u003cp\u003e· Fiber Reinforcement:\u003c/p\u003e\n\u003cp\u003e· The study highlights that the inclusion of MPP fibers significantly contributes to the mechanical strength of RCC. This is consistent with previous research that has shown polypropylene fibers can improve the toughness and ductility of concrete, reducing crack propagation and enhancing durability. The strategic positioning of fibers around cracks, as noted in the study, is also supported by literature emphasizing the role of fibers in controlling crack formation and improving resilience.\u003c/p\u003e\n\u003cp\u003e· Mix Design and Proportions:\u003c/p\u003e\n\u003cp\u003e· The mix design used in this study, mainly the reference mixture with a cement content of 14% and a water-to-cement ratio of 0.47, is comparable to other studies exploring optimal mix designs for RCC. Many researchers advocate for similar proportions to achieve desired strength and durability outcomes, reinforcing the validity of the chosen mix design in this study.\u003c/p\u003e\n\u003cp\u003e· Curing Methods:\u003c/p\u003e\n\u003cp\u003e· While the study does not delve deeply into curing methods, existing literature emphasizes the importance of proper curing in achieving the desired mechanical properties of concrete. Curing affects hydration and strength development, and studies have shown that inadequate curing can lead to significant reductions in strength and durability, which is a critical consideration in the context of RCC\u0026nbsp;.\u003c/p\u003e\n\u003cp\u003e· Environmental and Economic Benefits:\u003c/p\u003e\n\u003cp\u003e· The study mentions RCC's economic and operational advantages, which is supported by literature highlighting the lower cement content and simplified placement methods of RCC compared to conventional concrete. This aspect is increasingly relevant in discussions about sustainable construction practices and reducing the carbon footprint of concrete production.\u003c/p\u003e\n\u003cp\u003eIn summary, this study's findings are well-aligned with existing literature, reinforcing the understanding of how superplasticizers and MPP fibers can enhance the mechanical properties of roller-compacted concrete. The study contributes to the body of knowledge by providing empirical data that supports established theories and practices in concrete technology.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics declaration\u003c/strong\u003e:\u0026nbsp;Not applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics, Consent to Participate, and Consent to Publish declarations:\u0026nbsp;\u003c/strong\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent to Publish declaration:\u0026nbsp;\u003c/strong\u003eNot applicable\u003cstrong\u003e.\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent to Participate declaration:\u0026nbsp;\u003c/strong\u003eNot applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding information:\u0026nbsp;\u003c/strong\u003eThe authors state that no funding is involved.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAUTHOR CONTRIBUTION:\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAcknowledgement that all authors accepted the responsibility for the manuscript\u0026apos;s content and consented to its submission, reviewed all the results, and approved the final version.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eAuthor contribution: All authors have accepted responsibility for the entire content of this manuscript and consented to its submission to the journal, reviewed all the results, and approved the final version. S.F. S and M.H. designed the experiments and M.A carried them out. E.T prepared the manuscript with contributions from all co-authors.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements\u003c/strong\u003e: The authors thank Northern Technical University for generously providing all the facilities and essential scientific support required to complete this work.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of interest\u003c/strong\u003e: The authors state no conflict of interest.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData Availability Statement:\u0026nbsp;\u003c/strong\u003eAll data generated or analyzed during this study are included in this published article.\u0026nbsp;\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eS. D. Tayabji, T. W. Sherman, O. Keifer, A. Nanni, R. W. Piggott, D. Pittman, et al., \u0026quot;State-of-the-art report on roller-compacted concrete pavements,\u0026quot; 1995. \u003c/li\u003e\n\u003cli\u003eS. A. Ghahari, A. Mohammadi, and A. A. Ramezanianpour, \u0026quot;Performance assessment of natural pozzolan roller compacted concrete pavements,\u0026quot; Case studies in construction materials, vol. 7, pp. 82-90, 2017. \u003c/li\u003e\n\u003cli\u003eA. A. Ramezanianpour, A. Mohammadi, E. R. Dehkordi, and Q. B. Chenar, \u0026quot;Mechanical properties and durability of roller compacted concrete pavements in cold regions,\u0026quot; Construction and Building Materials, vol. 146, pp. 260-266, 2017/08/15/ 2017. \u003c/li\u003e\n\u003cli\u003eC. Chhorn, S. J. Hong, and S.-W. Lee, \u0026quot;A study on performance of roller-compacted concrete for pavement,\u0026quot; Construction and Building Materials, vol. 153, pp. 535-543, 2017/10/30/ 2017. \u003c/li\u003e\n\u003cli\u003eM. Pigeon and V. M. Malhotra, \u0026quot;Frost Resistance of Roller-Compacted High-Volume Fly Ash Concrete,\u0026quot; Journal of Materials in Civil Engineering, vol. 7, pp. 208-211, 1995/11/01 1995. \u003c/li\u003e\n\u003cli\u003eD. Harrington, F. Abdo, W. Adaska, C. V. Hazaree, H. Ceylan, and F. Bektas, \u0026quot;Guide for roller-compacted concrete pavements,\u0026quot; 2010. \u003c/li\u003e\n\u003cli\u003eACI, \u0026quot;Roller-compacted Mass Concrete,\u0026quot; 1999. \u003c/li\u003e\n\u003cli\u003eD. W. Pittman and S. A. Ragan, \u0026quot;Drying shrinkage of roller-compacted concrete for pavement applications,\u0026quot; Materials Journal, vol. 95, pp. 19-26, 1998. \u003c/li\u003e\n\u003cli\u003eA. Yerramala and K. G. Babu, \u0026quot;Transport properties of high volume fly ash roller compacted concrete,\u0026quot; Cement and Concrete composites, vol. 33, pp. 1057-1062, and 2011. \u003c/li\u003e\n\u003cli\u003eD. P. Bentz and C. F. Ferraris, \u0026quot;Rheology and setting of high volume fly ash mixtures,\u0026quot; Cement and Concrete Composites, vol. 32, pp. 265-270, 2010. \u003c/li\u003e\n\u003cli\u003eIraqi Organization Standardization and Quality Control, No. 5, \u0026ldquo;Standard Specifications for Portland Cement\u0026rdquo;, Baghdad, Iraq (2019).\u003c/li\u003e\n\u003cli\u003eAmerican Concrete Institute Committee ACI 211.3R, Guide for Selecting Proportions for No-Slump Concrete.\u003c/li\u003e\n\u003cli\u003eASTM C494/C494 M, \u0026quot;Standard Specifications for Chemical Admixtures for Concrete\u0026quot;, The American Society for Testing and Materials, Philadelphia, (2015).\u003c/li\u003e\n\u003cli\u003eK. H. Khayat and N. A. Libre, \u0026quot;Roller compacted concrete: field evaluation and mixture optimization,\u0026quot; Missouri University of Science and Technology. Center for Transportation Infrastructure and Safety2014. \u003c/li\u003e\n\u003cli\u003eP.S. Songa, S. Hwangb, B.C. Sheub \u0026ldquo;Strength properties of nylon- and polypropylene-fiber-reinforced concretes\u0026rdquo; Cement and Concrete Research 35 (2005) 1546\u0026ndash;1550 June 2004\u003c/li\u003e\n\u003cli\u003eTop\u0026ccedil;u B, Canbaz M. Effect of different fibers on the mechanical properties of concrete containing fly ash. Constr Build Mater 2007; 21:1486\u0026ndash;91.\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":"Roller Compacted Concrete (RCC), Super Plasticizers, Macro Polypropylene Fiber","lastPublishedDoi":"10.21203/rs.3.rs-6143187/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6143187/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eLaboratory experiments were conducted to assess the influence of incorporating varying quantities of superplasticizers and Macro PP Fiber on the mechanical properties and microstructure of roller-compacted concrete. The investigation comprised nine concrete mixtures, including a baseline mixture (C1) representing conventional concrete without superplasticizers and fiber. Additionally, five mixtures (C2, C3, C4, C5, and C6) incorporated different concentrations of superplasticizers (0.7%, 1.0%, 1.5%, 2.0%, and 2.5% of the cement content). In comparison, the remaining three mixtures (C7, C8, and C9) included varying amounts of Macro PP fiber (1, 3, and 5 kg/m\u003csup\u003e3\u003c/sup\u003e of concrete, respectively).\u003c/p\u003e\n\u003cp\u003eThe findings reveal a direct correlation between the superplasticizer content and both compressive and tensile strengths\u003c/p\u003e\n\u003cp\u003eAdditionally, the results indicate that the inclusion of polypropylene fibers in roller-compacted concrete yielded satisfactory mechanical strength outcomes. The PP fibers were strategically positioned about the cracks, enhancing the overall durability and resilience of the concrete.\u003c/p\u003e","manuscriptTitle":"Influence of Adding Different Amounts of Super Plasticizers and Macro Polypropylene Fiber on the Mechanical Properties and Microstructure of Roller Compacted Concrete","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-04-02 16:12:32","doi":"10.21203/rs.3.rs-6143187/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":"a1e7677e-9f8e-4c6a-8e93-077cb12fe00d","owner":[],"postedDate":"April 2nd, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-04-14T11:38:52+00:00","versionOfRecord":[],"versionCreatedAt":"2025-04-02 16:12:32","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-6143187","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6143187","identity":"rs-6143187","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}