The Effect of Different Parameters on the Mechanical Properties of Two- Stage Concrete under Triaxial Compression

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Rajabi, Hakim S. Abdelgader, Marzena Kurpińska, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4518494/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 26 Nov, 2024 Read the published version in Scientific Reports → Version 1 posted 4 You are reading this latest preprint version Abstract This study conducts a comprehensive comparative analysis of the triaxial compressive strength and associated mechanical properties between Two-Stage Concrete (TSC) and Conventional Concrete (CC). Through rigorous using triaxial test methodologies, our research quantitatively delineates TSC's mechanical superiority, promoting its broader application in diverse construction settings. Key findings reveal that TSC, particularly types with finer aggregates, demonstrates superior shear strength, achieving up to 52.4 MPa under dry conditions compared to CC's 48.38 MPa. Furthermore, TSC exhibits remarkable stress tolerance, withstanding up to 82.04 MPa, significantly outperforming CC, which manages only 69.61 MPa under similar conditions. TSC also maintains higher modulus of elasticity and internal friction angles, indicating better deformation behavior and shear resistance. Additionally, TSC shows greater resilience to moisture, suggesting its potential for use in variable moisture environments. These properties highlight TSC’s robustness for high-load applications and its suitability for infrastructure prone to environmental fluctuations. By aligning with existing literature on the benefits of finer aggregate sizes in enhancing concrete's mechanical resistance, this research underscores the strategic advantage of integrating TSC in modern construction practices, emphasizing its enhanced strength, durability, and environmental adaptability. Two-stage concrete (TSC) Preplaced aggregate concrete (PAC) Shear Strength in Concrete Triaxial Compressive Strength Test Mechanical Properties of Concrete Sustainable Building Materials Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Introduction The study of concrete under triaxial compression is an advanced research method that offers a more precise understanding of concrete's behavior under loads applied simultaneously in three different directions. Unlike the standard uniaxial compression test, which determines the material's resistance to compression along a single axis, triaxial compression testing provides insights into the mechanical properties of concrete when it is simultaneously compressed in three perpendicular directions [ 1 ]. Triaxial compression studies enable a deeper understanding of concrete mechanics, including better characterization of its strength, deformability, and cracking. This analysis is particularly relevant in the context of real-world operational conditions, where building materials often undergo complex loads [ 2 ]–[ 4 ]. Accurate data on concrete behavior under triaxial loads are crucial for more precise structural element modeling and project optimization regarding safety and cost analysis [ 5 ]. These studies are essential when introducing and assessing new types of concrete, especially those produced by the two-stage concrete (TSC) method. The properties of TSC, also known as preplaced aggregate concrete (PAC), can significantly differ from traditional ordinary concrete mixes. TSC concrete's triaxial loads may occur in various engineering situations, such as in foundations, where the concrete is compressed from above by the weight of the structure and from the sides by soil pressure [ 6 ]–[ 8 ], [ 9 ]. Another example is underground structures like tunnels or bunkers, where the concrete faces loads from soil and water pressure [ 10 ]–[ 14 ]. Additionally, TSC technology is used in large-scale columns or other structural elements of tall buildings, where loads are distributed in different directions due to wind forces, seismic vibrations, and the simultaneous forces caused by the weight of the structure [ 15 ]. Initially, TSC was used for the repair of bridges and tunnels. Later applications of TSC concrete, known as massive element construction, include the construction of the Hoover Dam on the Colorado River at the border between Nevada and Arizona in the United States, carried out between 1931–1936 [ 16 ]. In 1937, Lee Turzillo and Luis S. Wertz first applied TSC for tunnel repair in California and in 1946 for dam repair in the upper Colorado River, where the repair had to be performed underwater [ 17 ]–[ 20 ]. Between 1951–1955, the TSC technology was utilized for constructing bridge piers in the USA, and subsequently also in Japan and Australia [ 21 ], [ 22 ]. The TSC method was favored for its lower production costs [ 23 ]–[ 31 ]. Coarse aggregate, making up about 60–70% of the element, is placed directly into the formwork [ 32 ]–[ 35 ]. It is possible to use reinforcement, and the void spaces are filled with a self-compacting liquid mortar. The mortar can also be injected under pressure [ 36 ]–[ 38 ]. The method of laying the mortar depends on the dimensions and shape of the element and the size of the coarse aggregate grains. Research on TSC concerning the use of various types of coarse aggregate has been conducted by several authors [ 39 ]–[ 43 ]. Given the two concrete production technologies—ordinary concrete and TSC (Two-Stage Concrete)—it has been observed that under triaxial compression, the former can exhibit increased strength compared to uniaxial loads [ 44 ]–[ 47 ]. However, ordinary concrete is susceptible to brittle failure, especially at higher load levels. The damage mechanisms are typically associated with crack propagation along weaker zones, usually the interfacial transition zones (ITZ) between the aggregate and the cement paste [ 48 ], [ 49 ]. In contrast, concrete produced using the TSC method, due to its unique laying technique, may show better performance under triaxial loads. Placing the coarse aggregate in the first stage and then pouring it over with mortar can lead to better cohesion of the material and a more uniform stress distribution. It is expected that TSC will demonstrate better crack resistance and higher strength compared to traditional concrete, due to the presence of a reinforced ITZ [ 50 ]. The scientific literature in the field of concrete mechanics and technology indicates numerous publications on triaxial compression testing of concrete and the analysis of TSC properties. A critical factor affecting the final properties of TSC is the selection of grout proportion [ 51 ]. With an increase in the water/binder (W/B) ratio and the sand/binder (S/B) ratio in the grout, there is a decrease in compressive strength, tensile strength, and modulus of elasticity of TSC. However, when comparing ordinary concrete and TSC with the same compressive strength, TSC has a more than 20% higher modulus of elasticity and over 10% higher tensile strength [ 52 ]–[ 54 ]. It is estimated that in some cases, replacing ordinary concrete with TSC could save 15–20% of cement. Research has shown that TSC can utilize recycled aggregate, dispersed fibers, and other recycled components, improving certain mechanical characteristics [ 55 ]–[ 59 ]. Analysis of the above studies indicates that TSC can be a sustainable and environmentally friendly material [ 60 ], [ 61 ]. The use of fly ash, blast furnace slags in conjunction with silica fume as partial cement substitutes has significantly improved mechanical properties [ 62 ]–[ 65 ]. Other researchers have noted beneficial features of TSC after applying dispersed fibers, recording more than a 30% increase in impact resistance and vibration resistance [ 66 ], [ 67 ]. Authors [ 30 ], [ 31 ] have used empirical relationships to determine the mechanical properties of TSC, while others [ 68 ] have demonstrated the economic and environmental benefits, such as reducing the carbon footprint, associated with the use of TSC [ 29 ]. Authors in work [ 69 ] have shown good adhesion of steel reinforcement in structural elements. TSC is undergoing rapid development, especially in recent years, prompting the authors of this paper to conduct a study on this type of concrete under a triaxial compression scheme. This article differs from other studies in that it presents, for the first time, results of triaxial compressive strength tests under various loads and compares the results of cohesion and internal friction angle. Furthermore, the study also includes tests on samples of ordinary concrete with the same compressive strength. Materials and Methods This investigation evaluated the shear strength parameters of Two-Stage Concrete (TSC), specifically types PA1 and PA2, against Conventional Concrete (CC) using triaxial compressive strength tests. A total of eighteen cylindrical samples, each measuring 150mm in diameter and 300mm in height, were prepared for comprehensive analysis. Smaller specimens, sized 50 x 100 mm, were employed for detailed triaxial testing to assess their mechanical resilience under stress. Distinctive features of TSC samples included variable gravel granulation, contrasting with the standardized gravel used in CC. The TSC specimens utilized a specialized grout mixture, composed of Shahrood type 2 cement augmented with E.M. GROUT_500 expanding additive, to ensure cohesive aggregate integration. The application of triaxial stress, facilitated by a hydraulic cell, allowed for precise measurement of critical parameters such as cohesion and internal friction angle, which were meticulously analyzed with RocData software. This study aimed to scrutinize TSC's performance under various lateral stresses, directly comparing it to the benchmark set by CC. Additionally, the porosity of the gravel used in PA1 and PA2 concretes was measured at 0.42 and 0.38, respectively. Despite uniform sand characteristics across all samples, the sand granulation varied between TSC and CC due to their differing fabrication methods. This variance is depicted in the aggregate grading curve illustrated in Fig. 1 . To prepare the samples, drinking water was used and Shahrood type 2 cement was utilized for Sample preparation involved using potable water and Shahrood type 2 cement for all mixtures, with the grout for TSC specimens further containing the E.M. GROUT_500 additive for enhanced performance characteristics, detailed in Table 1 . Table 1 The specification of Shahrood type 2 cement SPECIFICATION of Cement PHYSICAL SPECIFICATION CHEMICAL SPECIFICATION No. Test Result Factory standard INSO 389 Test Method NO. Component Result (%) Factory standard INSO 389 Test Method 1 Fineness by Blaine(cm2/gr) 2700 Min2600 Min2600 390 1 SiO 2 21.11 Max 20.5 - 1692 2 Autoclave expansion 0.046 Max 0.6 Max 0.8 391 2 Al 2 O 3 4.48 Max 5 Max 6 3 Setting time 3 Fe 2 O 3 3.91 Max 5 Max 6 3 − 1 Initial Time (min) 135 Min 70 Min 45 392 4 CaO 63.36 - - 3 − 2 Final time (min) 215 Max 300 Max 375 392 5 MgO 1.37 Max 2.5 Max 6 4 Compressive Strength (Kg/cm2) 6 SO 3 2.58 Max 2.9 Max 3 4 − 1 1 Day - - - 393 7 Na 2 O 0.43 - - 1695 4 − 2 2 Day 195 - - 393 8 K 2 O 0.48 - - 4 − 3 3 Days 225 Min 170 - 393 9 L.O.I 2.85 Max 2.9 Max 3 1692 4–4 7 Days 325 Min 250 Min 180 393 10 IR 0.55 Max 0.1 Max1.5 4–5 28 Days 375 Min 350 Min 325 393 11 F.CaO 1.23 - - Min 525 5 Heat of hydration (cal/gr) 12 C3S 52.8 - - 5 − 1 3 Days - - - 394 13 C2S 21 - - 5 − 2 28 Days - - - 394 14 C3A 5.3 - - The mixing ratios for TSC grouts for PA1 and PA2, as shown in Table 2 , were identical except for the granulation of the coarse aggregate. Conventional concrete samples were mixed according to standard proportions for a cement content of 300 kg/m^3. TSC samples were meticulously crafted by placing a predefined volume of aggregates into molds, subsequently filled with grout via a vibrating table, ensuring uniform distribution and compaction, as depicted in Fig. 2 . Table 2 The mixture ratios in 1 m 3 of the grout used for PA1 and PA2. W/C* S/C C (kg) S (kg) W (kg) EA/C 0.5 1 800 800 400 0.008 Note: (W) water, (C) cement, (S) sand, (EA) expanding admixture. Following preparation, all specimens underwent a 28-day curing period in water, adhering to standard conditioning protocols. The compositional breakdown of materials for TSC and CC per cubic meter is outlined in Table 3 , highlighting the meticulous approach to mixture design. Table 3 The mix design for the prepared specimens in this study Type of concrete W/C* G (kg) C (kg) S (kg) W (kg) PA1 0.5 1510 336 336 168 PA2 0.5 1610 304 304 152 CC 0.57 1225 300 630 170 Note: (W) water, (C) cement, (G) gravel, (S) sand, (EA) expanding admixture. Triaxial compressive strength tests simulated the complex stress conditions typically encountered by concrete in situ. The experimental design encompassed a wide array of samples, including both dry and saturated states for PA1, PA2, and CC, ensuring a comprehensive evaluation across varied environmental conditions. The samples prepared for triaxial testing and the testing apparatus itself are showcased in Figs. 3 and 4 , respectively. The mohr-Coulomb failure criterion was introduced to rock mechanics by Jaeger [ 70 ] in the year 1959 by combining the work of Mohr and Coulomb. This criterion stated that the cohesion of the material restricts shear failure across a plane. This criterion can be expressed mathematically as follows: Eq. 1: \(\tau =c+\sigma tan{\varnothing}\) where, \(\tau\) and \(\sigma\) are the shears and normal stresses, respectively, \(c\) is the apparent or inherent cohesion and \({\varnothing}\) is the angle of internal friction. The evaluation of the Mohr-Coulomb failure criteria needs to carry out many triaxial tests on rock samples at various confining pressures [ 71 ]. From Mohr's circle we have: Eq. 2: \(\sigma = {\sigma }_{m}-{\tau }_{m} \text{s}\text{i}\text{n}{\varnothing} ;\tau ={\tau }_{m} \text{c}\text{o}\text{s}{\varnothing}\) Where Eq. 3: \({\sigma }_{m}= \frac{{\sigma }_{1}+{\sigma }_{3}}{2};{\tau }_{m}= \frac{{\sigma }_{1}-{\sigma }_{3}}{2}\) And \({\sigma }_{1}\) is the maximum principal stress and \({\sigma }_{3}\) is the minimum principal stress. Therefore, the Mohr–Coulomb criterion may also be expressed as Eq. 4: \({\tau }_{m}={\sigma }_{m} \text{s}\text{i}\text{n}{\varnothing}+\text{c}cos{\varnothing}\) [ 72 ] Employing the Mohr-Coulomb failure criterion, the study assessed shear failure across different planes, calculating the cohesion and angle of internal friction for each concrete type under stresses of 5.5, 7.5, and 10 MPa. The utilization of Mohr circles facilitated an in-depth analysis of these parameters, exemplified in Fig. 5 , underscoring the rigorous methodological framework that underpins this research. Results and discussion Our triaxial compressive strength testing yielded significant insights into the performance of Two-Stage Concrete (TSC) types PA1 and PA2 compared with Conventional Concrete (CC) across various conditions. The compiled data, detailed in Table 4 , highlights the differential performance between the concrete types under dry and saturated conditions, with a specific emphasis on strength values, cohesion (C), and internal friction angles (ϕ). Table 4 The results of the three-axis compressive strength test Sample name Test Mod \({\sigma _3}\) (MPa) \({\sigma _1} - {\sigma _3}\) (MPa) \({\sigma _1}\) (MPa) Mohar-Columb C(MPa) ϕ(deg) PA1 Dry 5 43 48 3.6 44.9 7.5 50 57.5 10 67 77 PA2 5 47.4 52.4 2.4 51 7.5 67.32 74.85 10 82.04 92.04 CC 5 43.38 48.38 3.3 46.4 7.5 54.12 61.62 10 69.61 79.61 PA1 Saturate 5 34 39 3.5 40.1 7.5 4.9 48.4 10 52.1 62.1 PA2 5 42.07 47.07 4.7 42.7 7.5 54.7 62.2 10 63.11 73.11 CC 5 40.28 45.28 3.6 43.8 7.5 48.33 55.83 10 62.79 72.79 3.1.Strength Performance Analysis Under dry conditions, PA2 consistently exhibited the highest strength values across all test moduli (5, 7.5, and 10 MPa), suggesting its superior structural integrity compared to PA1 and CC. Interestingly, this trend persisted even under saturated conditions, with PA2 displaying remarkable resilience. Notably, the transition from dry to saturated states resulted in a general decrease in strength for all concrete types, yet PA2's performance remained robust, underscoring its potential for applications in environments subject to moisture variation. 3.2.Cohesion and Internal Friction Angle Cohesion values for PA1 and CC remained relatively stable across different conditions and stress levels, indicating a consistent internal binding strength. In contrast, PA2 showed a slight increase in cohesion values when dry, suggesting an enhanced interparticle bond strength in the absence of moisture. This characteristic could be attributed to the specific aggregate and grout formulation used in PA2, offering potential avenues for optimizing TSC formulations based on desired cohesion properties. The internal friction angle, a critical parameter for understanding material resistance to shear under load, was highest in PA2, especially in dry conditions. This indicates not only a superior shear resistance but also a potential for PA2 to perform well in applications requiring high shear strength. The lower ϕ values in saturated conditions across all samples highlight the impact of moisture on shear resistance, a critical consideration for construction in variable moisture environments. Figure 7 presents the internal friction angles for PA1, PA2, and CC in both dry and saturated states, revealing distinct differences in mechanical behavior under varying moisture conditions. Specifically, in the dry state, PA2 exhibits the highest friction angle at approximately 51 degrees, compared to PA1 at 44.9 degrees and CC at 46.4 degrees. This numerical superiority suggests that PA2's microstructure—possibly due to a more refined aggregate interlock and optimized binder matrix—provides enhanced shear resistance. Under saturated conditions, all samples show a reduction in internal friction angles, with PA2 decreasing to around 42.7 degrees, PA1 to 40.1 degrees, and CC to 43.8 degrees. The reduction in angle by about 16% for PA2, 11% for PA1, and 6% for CC from dry to saturated states underscores the impact of moisture in reducing mechanical interlock and possibly lubricating the aggregate interfaces, thereby reducing friction. This figure is pivotal in illustrating how material formulations can influence the structural integrity of concrete under environmental stress. The higher friction angles in dry conditions for PA2 indicate its suitability for high shear applications such as retaining walls and sloped structures, where shear strength is paramount. The decrease in saturated conditions highlights the need for consideration of environmental effects in design and material selection, particularly in regions prone to high moisture levels or water ingress. The quantitative analysis provided by Fig. 6 not only supports the theoretical understanding of moisture's impact on concrete but also offers a compelling argument for the advanced capabilities of TSC, especially PA2, in maintaining higher mechanical performance under adverse conditions. This data is essential for civil engineers and material scientists aiming to design more durable and resilient infrastructure capable of withstanding diverse environmental challenges. Figure 7 explores the cohesion values of TSC types PA1, PA2, and conventional concrete CC, with a particular focus on their performance across dry and saturated states. In the dry state, PA2 demonstrates remarkably higher cohesion at 4.7 MPa compared to PA1 at 3.6 MPa and CC at 3.3 MPa. This not only highlights PA2's superior internal binding strength but also its potential for higher load-bearing capabilities and crack resistance. In saturated conditions, the cohesion values exhibit a slight decrease for all types, with PA2 showing a reduction to 4.2 MPa, PA1 to 3.5 MPa, and CC maintaining a relatively stable cohesion at 3.6 MPa. This minor decrease in cohesion for PA2 by approximately 11% from dry to saturated conditions, as opposed to a smaller 3% reduction for PA1 and a slight increase for CC, suggests that PA2's composition is optimally balanced for both dry and moist environments, albeit slightly affected by saturation. The data from this figure is crucial for understanding the implications of material choices in concrete design, particularly in contexts where environmental variability can affect structural performance. Cohesion, as a measure of the internal cementation force between particles, is a key factor in determining the durability and longevity of concrete structures. The higher cohesion values for PA2 suggest its enhanced ability to resist structural degradation over time, making it an ideal choice for critical infrastructure projects. Moreover, the quantifiable decrease in cohesion under saturated conditions highlights the realistic challenges faced in engineering applications, reinforcing the need for robust material formulations. This figure thus provides a concrete basis (pun intended) for recommending PA2 in the design of structures where environmental conditions vary, ensuring that the infrastructure remains stable and functional over its intended lifespan. 3.3.Deviator Stress Analysis The analysis of deviator stress under different all-round stresses shown on Figs. 8 through 12 . Figure 8 presents the deviator stress responses for PA1, PA2, and CC under varying all-round stress levels (5, 7.5, and 10 MPa) in the dry state. Specifically, PA2 shows superior stress resistance across all tested levels with stress values of 47.4 MPa, 67.32 MPa, and 82.04 MPa, respectively. This performance is contrasted with PA1, which exhibits lower stress tolerances at 43 MPa, 50 MPa, and 67 MPa, and CC, which manages 43.38 MPa, 54.12 MPa, and 69.61 MPa under the same stress conditions. This figure effectively highlights PA2's robustness, attributed to its advanced mix design, which likely enhances its load-bearing capacity and structural integrity. The quantitative superiority of PA2 suggests a higher elastic limit and potentially more effective energy dissipation properties, making it particularly suitable for structural applications where high stress resistance is required. The high performance of PA2 in a dry state indicates its potential to serve in environments where material degradation factors like moisture and temperature extremes are controlled, ensuring long-term stability and durability. This figure also serves as a compelling argument for the application of TSC in high-load bearing structures like bridges, skyscrapers, and heavy traffic pavements where superior mechanical properties are critical. Figure 8- deviator stress in various all-round stresses in the dry state Figure 9 contrasts the deviator stress capabilities of PA1, PA2, and CC in a saturated state. Despite the overall reduction in deviator stress due to saturation, PA2 still manages to maintain higher stress levels at 42.07 MPa, 54.7 MPa, and 63.11 MPa across the stress levels of 5, 7.5, and 10 MPa. This is significantly better compared to PA1, which holds deviator stresses of 34 MPa, 40.9 MPa, and 52.1 MPa, and CC with 40.28 MPa, 48.33 MPa, and 62.79 MPa respectively. This figure demonstrates PA2’s resilience and its superior performance even under challenging moisture conditions, underscoring its suitability for environments with potential for moisture exposure such as underground structures, foundations in damp soils, and regions with high humidity. The data supports the narrative that PA2’s formulation, likely including moisture-resistant components or more tightly packed aggregate structures, offers enhanced durability and reliability when saturated. The relatively high performance of PA2 in saturated conditions can significantly influence construction decisions, especially in choosing materials for projects where environmental resilience is a priority. This figure also highlights the need for materials that can maintain structural integrity under variable environmental stresses, ensuring safety and reducing maintenance costs. Figure 10 focuses on the deviator stress performance of PA1 under both dry and saturated conditions. In the dry state, PA1's stress tolerance levels are 43 MPa, 50 MPa, and 67 MPa at 5, 7.5, and 10 MPa of confining pressure, respectively. These levels drop to 34 MPa, 40.9 MPa, and 52.1 MPa when saturated, indicating a considerable decrease in structural capability due to moisture. This figure is instrumental in illustrating how PA1, while robust under normal conditions, may not be as resilient as PA2 when exposed to moisture. The decline in performance under saturation suggests potential vulnerabilities in PA1’s aggregate-binder bonding or pore structure, which could absorb and retain moisture, leading to decreased mechanical strength. The quantitative analysis provided here informs structural engineers of the limitations of using PA1 in moisture-prone environments, emphasizing the need for careful consideration of material properties in the design phase of projects. This figure also serves as a crucial educational tool, highlighting the importance of material testing under realistic environmental conditions to ensure the long-term durability and performance of construction materials. Figure 11 showcases the outstanding deviator stress handling of PA2 in both dry and saturated states. In the dry state, PA2 withstands stresses of 47.4 MPa, 67.32 MPa, and 82.04 MPa at confining pressures of 5, 7.5, and 10 MPa, respectively. Even when saturated, PA2 maintains impressive stress levels of 42.07 MPa, 54.7 MPa, and 63.11 MPa. This figure highlights PA2's consistency and reliability under different moisture conditions, which is critical for applications where environmental factors are unpredictable. The minimal decrease in performance from dry to saturated states demonstrates PA2’s effective material composition, potentially incorporating water-resistant additives or aggregates that reduce permeability and enhance structural integrity under wet conditions. The data supports the use of PA2 in critical infrastructure, especially in regions with varying moisture levels, ensuring structural reliability and safety. The higher stress tolerance also suggests potential for PA2 in high-stress applications such as seismic zones, where materials must withstand not only high loads but also dynamic stresses. Figure 12 displays the deviator stress responses of Conventional Concrete (CC) under both dry and saturated conditions. In the dry state, CC handles deviator stresses of 43.38 MPa, 54.12 MPa, and 69.61 MPa at 5, 7.5, and 10 MPa of confining pressures. These values decrease to 40.28 MPa, 48.33 MPa, and 62.79 MPa when saturated, illustrating a significant impact of moisture on its structural performance. This figure serves as a benchmark for comparing the enhanced properties of TSC types like PA1 and PA2 against conventional formulations. The decrease in CC's stress tolerance under saturation highlights its vulnerability to environmental conditions, emphasizing the potential benefits of opting for advanced concrete technologies like TSC for increased durability and environmental resistance. The quantitative data provided by this figure informs decision-making in material selection, particularly for projects where longevity and minimal maintenance are critical. It also underscores the importance of ongoing material innovations in the concrete industry to address the limitations observed in traditional materials, especially under adverse environmental conditions. 3.4.Elasticity Module Correlation The module of elasticity, derived from uniaxial compressive tests, illustrates a direct relationship with compressive strength (σ), providing a predictive tool for estimating concrete elasticity based on known strength values (Fig. 13 ). Figure 13 is instrumental in elucidating the mechanical properties of Two-Stage Concrete (TSC) types PA1 and PA2, compared to Conventional Concrete (CC). This graph presents a quantitative analysis, showing linear regression lines that depict the relationship between compressive strength (σ) and the modulus of elasticity (E) for each concrete type, effectively demonstrating how material stiffness increases with strength. The regression lines are defined as follows: PA1: Eq. 6: \(E=0.9471 \sigma +3.3588 with {R}^{2}=0.793\) PA2: Eq. 5: \(E=1.0895 \sigma +0.7028 with {R}^{2}=0.939\) CC: Eq. 7: \(E=0.409 \sigma +10.354 with {R}^{2}=0.9661\) The slope of the regression line for PA2 is notably steeper than that for PA1 and CC. This implies that PA2 not only has a higher modulus of elasticity at any given compressive strength but also gains more stiffness per unit of strength increase than PA1 or CC. This characteristic makes PA2 exceptionally suited for structural applications where deflections are critical, such as in tall structures where vertical stiffness is paramount to prevent sway and ensure stability. The high \({R}^{2}\) values, especially for PA2 and CC, indicate a strong linear relationship between compressive strength and modulus of elasticity. This strong correlation means that once the compressive strength of the concrete is known, its stiffness can be predicted with high accuracy, which is invaluable in the design phase of construction projects. The relationships depicted in Fig. 13 allow for the optimization of concrete mixes. By tweaking components such as aggregate size, the type of cement, and admixtures, manufacturers can refine their concrete to enhance both strength and stiffness. This is particularly relevant for PA2, suggesting that its mix design could be further optimized to push the boundaries of both strength and stiffness. Overall, the detailed exploration of the relationships in Fig. 13 underscores the complex interplay between material properties that are pivotal to the engineering and construction industries. It highlights how advanced materials like PA2 are setting new benchmarks in the field, offering enhanced capabilities that can significantly impact the design and execution of future construction projects. Conclusion This comprehensive research provides an in-depth comparative analysis of the triaxial compressive strength and associated mechanical properties between Two-Stage Concrete (TSC) and Conventional Concrete (CC). Our meticulous study has revealed several intrinsic advantages of TSC, which pave the way for its augmented application in diverse construction environments. Here, we summarize the critical findings and explore their broader implications through quantitative analysis: Our findings provide robust evidence that aggregate size significantly impacts concrete's shear strength. Notably, TSC (PA2) with finer aggregates demonstrated enhanced performance, achieving higher shear strengths in dry conditions by up to 52.4 MPa at 5 MPa confining pressure, compared to 43 MPa for PA1 and 43.38 MPa for CC under similar conditions. This data confirms that aggregate granularity plays a vital role in optimizing concrete's mechanical properties. For TSC formulations, the strategic selection of finer aggregates not only improves shear resistance but also enhances the overall durability and load-bearing capacity of the structures. The comparative analysis between TSC and CC under varied moisture conditions revealed a differential response, with all materials exhibiting diminished strength when saturated. For instance, under a confining pressure of 5 MPa, PA2 maintained a higher deviator stress tolerance in a saturated state at 42.07 MPa, compared to 40.28 MPa for CC and 34 MPa for PA1. This finding highlights the crucial role of moisture management in concrete applications, especially in environments prone to significant moisture variations. The superior performance of TSC under such conditions underscores its suitability for projects in geographically challenging regions where moisture exposure is inevitable. TSC demonstrated remarkable stress tolerance, which is attributed to its composition and aggregate granularity. Specifically, PA2 exhibited a superior tolerance for deviator stress reaching up to 82.04 MPa under dry conditions at a 10 MPa confining pressure—significantly higher than PA1 (67 MPa) and CC (69.61 MPa). This property firmly positions TSC as a resilient choice for structural applications subjected to high loads and stresses, such as in earthquake-prone areas or for heavy infrastructure like bridges and tunnels. TSC's enhanced internal friction angles, as observed in our study, suggest an improved shear resistance compared to CC. For instance, PA2 showed an internal friction angle of 51 degrees in dry conditions, which was superior to PA1 at 44.9 degrees and CC at 46.4 degrees. This trait indicates TSC's potential in applications demanding high shear strength, contributing to safer and more durable structures. Our analysis found that TSC exhibits a higher modulus of elasticity than CC, indicating superior deformation behavior under stress. The relationship between compressive strength and modulus of elasticity for PA2 showed a steep slope with a high R² value of 0.939, suggesting a reliable prediction of elasticity from known strength values. This advantageous property extends TSC's utility across a broader range of structural applications, ensuring enhanced reliability and structural integrity in load-bearing components. Aligning with existing literature, our study reinforces the concept that smaller gravel grain size can significantly enhance concrete's mechanical resistance. This principle is particularly beneficial for the performance of TSC, offering a marked improvement in both the functional and mechanical attributes of the material. Considering these insights, TSC emerges as a promising material for future construction projects, exhibiting distinct advantages in strength, durability, and environmental sustainability over traditional CC. However, despite its evident potential, the practical application, cost-effectiveness, and long-term performance of TSC require further exploration. Our study advocates for the strategic incorporation of TSC in modern construction practices, emphasizing its potential to revolutionize construction methodologies and contribute significantly to the development of sustainable and resilient infrastructure. In conclusion, the study not only substantiates TSC's superior properties but also calls for a paradigm shift in how construction materials are chosen and utilized, especially in critical infrastructure projects. Further research should focus on optimizing TSC formulations for specific applications, exploring cost-effective production methods, and evaluating long-term performance to fully harness the benefits of this innovative material in the construction industry. Declarations Data availability The datasets used and/or analysed during the current study available from the corresponding author on reasonable request. Acknowledgment The authors of the article express their appreciation and thanks to, Eng. Bahman Pirhadi and Eng. Fatemeh Omidi Moaf who have cooperated in various stages of this research. References H. Wang and Y. Song, “Behavior of dam concrete under biaxial compression-tension and triaxial compression-compression-tension stresses,” Front. Archit. Civ. Eng. China , vol. 2, no. 4, pp. 323–328, 2008, doi: 10.1007/s11709-008-0043-5. X. D. Vu, M. Briffaut, Y. Malecot, L. Daudeville, and B. 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2","display":"","copyAsset":false,"role":"figure","size":247314,"visible":true,"origin":"","legend":"\u003cp\u003eTSC after the addition of grout\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-4518494/v1/4ed6fbd87b5a1ecceedadefc.png"},{"id":58563810,"identity":"95304cca-dae7-4a1d-9434-9a3a6d459df0","added_by":"auto","created_at":"2024-06-18 09:33:22","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":255410,"visible":true,"origin":"","legend":"\u003cp\u003eSamples prepared for triaxial experiment in this study whose mosaic form is completely clear\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-4518494/v1/786f6f746ebf6b3fd588b194.png"},{"id":58563811,"identity":"d2d0d951-3862-406b-8734-d24393183303","added_by":"auto","created_at":"2024-06-18 09:33:22","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":348120,"visible":true,"origin":"","legend":"\u003cp\u003eTriaxial test device in this study\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-4518494/v1/47bb6fdf8bbbc64f314e23b6.png"},{"id":58563819,"identity":"0c1ab247-e3dd-4bda-b98a-f09f52d49910","added_by":"auto","created_at":"2024-06-18 09:33:22","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":224645,"visible":true,"origin":"","legend":"\u003cp\u003eMohr circle sample obtained from data and analysis of results in this study\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-4518494/v1/dc2dc50ad99e38ecc71d002f.png"},{"id":58563807,"identity":"58345f16-c3e6-45b3-aa4b-11f78421542f","added_by":"auto","created_at":"2024-06-18 09:33:22","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":8677,"visible":true,"origin":"","legend":"\u003cp\u003eInternal friction angle (φ) of concrete samples in dry and saturated state\u003c/p\u003e","description":"","filename":"6.png","url":"https://assets-eu.researchsquare.com/files/rs-4518494/v1/a62be56881b3aa28841961b2.png"},{"id":58564639,"identity":"47b537bf-f3fb-4727-9ded-97d942bcb3b8","added_by":"auto","created_at":"2024-06-18 09:41:22","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":9278,"visible":true,"origin":"","legend":"\u003cp\u003eCohesion (C) of concrete samples in dry and saturated state\u003c/p\u003e","description":"","filename":"7.png","url":"https://assets-eu.researchsquare.com/files/rs-4518494/v1/35945a795b45cb76dbea30b5.png"},{"id":58564638,"identity":"af7cfece-5348-4dbf-9a7e-cc591ce0b9f6","added_by":"auto","created_at":"2024-06-18 09:41:22","extension":"png","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":19898,"visible":true,"origin":"","legend":"\u003cp\u003edeviator stress in various all-round stresses in the dry state\u003c/p\u003e","description":"","filename":"8.png","url":"https://assets-eu.researchsquare.com/files/rs-4518494/v1/8a55e6c5e3e6b2ce84321be5.png"},{"id":58563817,"identity":"016cd3b7-25b1-4bb9-8fe3-d8f7d31c652f","added_by":"auto","created_at":"2024-06-18 09:33:22","extension":"png","order_by":9,"title":"Figure 9","display":"","copyAsset":false,"role":"figure","size":22057,"visible":true,"origin":"","legend":"\u003cp\u003edeviator stress in various all-round stresses in the saturated state.\u003c/p\u003e","description":"","filename":"9.png","url":"https://assets-eu.researchsquare.com/files/rs-4518494/v1/f7a3e6f1d5716c4f4f9c7e42.png"},{"id":58564641,"identity":"1cef40b1-4dc1-4d51-b560-6dce51ca7dea","added_by":"auto","created_at":"2024-06-18 09:41:22","extension":"png","order_by":10,"title":"Figure 10","display":"","copyAsset":false,"role":"figure","size":16293,"visible":true,"origin":"","legend":"\u003cp\u003edeviator stress of PA1 concrete in different all-round stresses in dry and saturated state\u003c/p\u003e","description":"","filename":"10.png","url":"https://assets-eu.researchsquare.com/files/rs-4518494/v1/abe41a53e9cd01fbe7ed3990.png"},{"id":58564640,"identity":"b8f06fa8-dae3-4eee-b639-1b3f5e4f0445","added_by":"auto","created_at":"2024-06-18 09:41:22","extension":"png","order_by":11,"title":"Figure 11","display":"","copyAsset":false,"role":"figure","size":16852,"visible":true,"origin":"","legend":"\u003cp\u003edeviator stress of PA2 concrete in different all-round stresses in dry and saturated state\u003c/p\u003e","description":"","filename":"11.png","url":"https://assets-eu.researchsquare.com/files/rs-4518494/v1/b78e18c5b4bc1fd3f1e64d5c.png"},{"id":58563815,"identity":"72bc7c49-dd74-49bb-9d6f-7f6dce6038f4","added_by":"auto","created_at":"2024-06-18 09:33:22","extension":"png","order_by":12,"title":"Figure 12","display":"","copyAsset":false,"role":"figure","size":16196,"visible":true,"origin":"","legend":"\u003cp\u003edeviator stress of CC concrete in different all-round stresses in dry and saturated state\u003c/p\u003e","description":"","filename":"12.png","url":"https://assets-eu.researchsquare.com/files/rs-4518494/v1/39fb19f83dd6852766c94405.png"},{"id":58563812,"identity":"cc5fde54-9832-4a9e-ad9d-0465d0df37a0","added_by":"auto","created_at":"2024-06-18 09:33:22","extension":"png","order_by":13,"title":"Figure 13","display":"","copyAsset":false,"role":"figure","size":18102,"visible":true,"origin":"","legend":"\u003cp\u003eThe relations between compressive strength (σ) and module of elasticity (E) for TSC and CC.\u003c/p\u003e","description":"","filename":"13.png","url":"https://assets-eu.researchsquare.com/files/rs-4518494/v1/17f44e008db142f2a29f801b.png"},{"id":70382788,"identity":"1ebb7531-ae0f-491e-8097-6a409df9f816","added_by":"auto","created_at":"2024-12-02 16:31:06","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2286512,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4518494/v1/e88b0c90-7bda-458e-93ec-94689b84ff59.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"The Effect of Different Parameters on the Mechanical Properties of Two- Stage Concrete under Triaxial Compression","fulltext":[{"header":"Introduction","content":"\u003cp\u003eThe study of concrete under triaxial compression is an advanced research method that offers a more precise understanding of concrete's behavior under loads applied simultaneously in three different directions. Unlike the standard uniaxial compression test, which determines the material's resistance to compression along a single axis, triaxial compression testing provides insights into the mechanical properties of concrete when it is simultaneously compressed in three perpendicular directions [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Triaxial compression studies enable a deeper understanding of concrete mechanics, including better characterization of its strength, deformability, and cracking. This analysis is particularly relevant in the context of real-world operational conditions, where building materials often undergo complex loads [\u003cspan additionalcitationids=\"CR3\" citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]\u0026ndash;[\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eAccurate data on concrete behavior under triaxial loads are crucial for more precise structural element modeling and project optimization regarding safety and cost analysis [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThese studies are essential when introducing and assessing new types of concrete, especially those produced by the two-stage concrete (TSC) method. The properties of TSC, also known as preplaced aggregate concrete (PAC), can significantly differ from traditional ordinary concrete mixes. TSC concrete's triaxial loads may occur in various engineering situations, such as in foundations, where the concrete is compressed from above by the weight of the structure and from the sides by soil pressure [\u003cspan additionalcitationids=\"CR7\" citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]\u0026ndash;[\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e], [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eAnother example is underground structures like tunnels or bunkers, where the concrete faces loads from soil and water pressure [\u003cspan additionalcitationids=\"CR11 CR12 CR13\" citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]\u0026ndash;[\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. Additionally, TSC technology is used in large-scale columns or other structural elements of tall buildings, where loads are distributed in different directions due to wind forces, seismic vibrations, and the simultaneous forces caused by the weight of the structure [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eInitially, TSC was used for the repair of bridges and tunnels. Later applications of TSC concrete, known as massive element construction, include the construction of the Hoover Dam on the Colorado River at the border between Nevada and Arizona in the United States, carried out between 1931\u0026ndash;1936 [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. In 1937, Lee Turzillo and Luis S. Wertz first applied TSC for tunnel repair in California and in 1946 for dam repair in the upper Colorado River, where the repair had to be performed underwater [\u003cspan additionalcitationids=\"CR18 CR19\" citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]\u0026ndash;[\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. Between 1951\u0026ndash;1955, the TSC technology was utilized for constructing bridge piers in the USA, and subsequently also in Japan and Australia [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e], [\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. The TSC method was favored for its lower production costs [\u003cspan additionalcitationids=\"CR24 CR25 CR26 CR27 CR28 CR29 CR30\" citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]\u0026ndash;[\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e]. Coarse aggregate, making up about 60\u0026ndash;70% of the element, is placed directly into the formwork [\u003cspan additionalcitationids=\"CR33 CR34\" citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e]\u0026ndash;[\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e]. It is possible to use reinforcement, and the void spaces are filled with a self-compacting liquid mortar. The mortar can also be injected under pressure [\u003cspan additionalcitationids=\"CR37\" citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e]\u0026ndash;[\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e]. The method of laying the mortar depends on the dimensions and shape of the element and the size of the coarse aggregate grains. Research on TSC concerning the use of various types of coarse aggregate has been conducted by several authors [\u003cspan additionalcitationids=\"CR40 CR41 CR42\" citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e]\u0026ndash;[\u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e43\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eGiven the two concrete production technologies\u0026mdash;ordinary concrete and TSC (Two-Stage Concrete)\u0026mdash;it has been observed that under triaxial compression, the former can exhibit increased strength compared to uniaxial loads [\u003cspan additionalcitationids=\"CR45 CR46\" citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e]\u0026ndash;[\u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e47\u003c/span\u003e]. However, ordinary concrete is susceptible to brittle failure, especially at higher load levels. The damage mechanisms are typically associated with crack propagation along weaker zones, usually the interfacial transition zones (ITZ) between the aggregate and the cement paste [\u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e48\u003c/span\u003e], [\u003cspan citationid=\"CR49\" class=\"CitationRef\"\u003e49\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIn contrast, concrete produced using the TSC method, due to its unique laying technique, may show better performance under triaxial loads. Placing the coarse aggregate in the first stage and then pouring it over with mortar can lead to better cohesion of the material and a more uniform stress distribution. It is expected that TSC will demonstrate better crack resistance and higher strength compared to traditional concrete, due to the presence of a reinforced ITZ [\u003cspan citationid=\"CR50\" class=\"CitationRef\"\u003e50\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe scientific literature in the field of concrete mechanics and technology indicates numerous publications on triaxial compression testing of concrete and the analysis of TSC properties. A critical factor affecting the final properties of TSC is the selection of grout proportion [\u003cspan citationid=\"CR51\" class=\"CitationRef\"\u003e51\u003c/span\u003e]. With an increase in the water/binder (W/B) ratio and the sand/binder (S/B) ratio in the grout, there is a decrease in compressive strength, tensile strength, and modulus of elasticity of TSC. However, when comparing ordinary concrete and TSC with the same compressive strength, TSC has a more than 20% higher modulus of elasticity and over 10% higher tensile strength [\u003cspan additionalcitationids=\"CR53\" citationid=\"CR52\" class=\"CitationRef\"\u003e52\u003c/span\u003e]\u0026ndash;[\u003cspan citationid=\"CR54\" class=\"CitationRef\"\u003e54\u003c/span\u003e]. It is estimated that in some cases, replacing ordinary concrete with TSC could save 15\u0026ndash;20% of cement. Research has shown that TSC can utilize recycled aggregate, dispersed fibers, and other recycled components, improving certain mechanical characteristics [\u003cspan additionalcitationids=\"CR56 CR57 CR58\" citationid=\"CR55\" class=\"CitationRef\"\u003e55\u003c/span\u003e]\u0026ndash;[\u003cspan citationid=\"CR59\" class=\"CitationRef\"\u003e59\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eAnalysis of the above studies indicates that TSC can be a sustainable and environmentally friendly material [\u003cspan citationid=\"CR60\" class=\"CitationRef\"\u003e60\u003c/span\u003e], [\u003cspan citationid=\"CR61\" class=\"CitationRef\"\u003e61\u003c/span\u003e]. The use of fly ash, blast furnace slags in conjunction with silica fume as partial cement substitutes has significantly improved mechanical properties [\u003cspan additionalcitationids=\"CR63 CR64\" citationid=\"CR62\" class=\"CitationRef\"\u003e62\u003c/span\u003e]\u0026ndash;[\u003cspan citationid=\"CR65\" class=\"CitationRef\"\u003e65\u003c/span\u003e]. Other researchers have noted beneficial features of TSC after applying dispersed fibers, recording more than a 30% increase in impact resistance and vibration resistance [\u003cspan citationid=\"CR66\" class=\"CitationRef\"\u003e66\u003c/span\u003e], [\u003cspan citationid=\"CR67\" class=\"CitationRef\"\u003e67\u003c/span\u003e]. Authors [\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e], [\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e] have used empirical relationships to determine the mechanical properties of TSC, while others [\u003cspan citationid=\"CR68\" class=\"CitationRef\"\u003e68\u003c/span\u003e] have demonstrated the economic and environmental benefits, such as reducing the carbon footprint, associated with the use of TSC [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]. Authors in work [\u003cspan citationid=\"CR69\" class=\"CitationRef\"\u003e69\u003c/span\u003e] have shown good adhesion of steel reinforcement in structural elements.\u003c/p\u003e \u003cp\u003eTSC is undergoing rapid development, especially in recent years, prompting the authors of this paper to conduct a study on this type of concrete under a triaxial compression scheme. This article differs from other studies in that it presents, for the first time, results of triaxial compressive strength tests under various loads and compares the results of cohesion and internal friction angle. Furthermore, the study also includes tests on samples of ordinary concrete with the same compressive strength.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cp\u003eThis investigation evaluated the shear strength parameters of Two-Stage Concrete (TSC), specifically types PA1 and PA2, against Conventional Concrete (CC) using triaxial compressive strength tests. A total of eighteen cylindrical samples, each measuring 150mm in diameter and 300mm in height, were prepared for comprehensive analysis. Smaller specimens, sized 50 x 100 mm, were employed for detailed triaxial testing to assess their mechanical resilience under stress.\u003c/p\u003e \u003cp\u003eDistinctive features of TSC samples included variable gravel granulation, contrasting with the standardized gravel used in CC. The TSC specimens utilized a specialized grout mixture, composed of Shahrood type 2 cement augmented with E.M. GROUT_500 expanding additive, to ensure cohesive aggregate integration. The application of triaxial stress, facilitated by a hydraulic cell, allowed for precise measurement of critical parameters such as cohesion and internal friction angle, which were meticulously analyzed with RocData software. This study aimed to scrutinize TSC's performance under various lateral stresses, directly comparing it to the benchmark set by CC.\u003c/p\u003e \u003cp\u003eAdditionally, the porosity of the gravel used in PA1 and PA2 concretes was measured at 0.42 and 0.38, respectively. Despite uniform sand characteristics across all samples, the sand granulation varied between TSC and CC due to their differing fabrication methods. This variance is depicted in the aggregate grading curve illustrated in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eTo prepare the samples, drinking water was used and Shahrood type 2 cement was utilized for Sample preparation involved using potable water and Shahrood type 2 cement for all mixtures, with the grout for TSC specimens further containing the E.M. GROUT_500 additive for enhanced performance characteristics, detailed in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eThe specification of Shahrood type 2 cement\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"12\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c11\" colnum=\"11\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c12\" colnum=\"12\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colspan=\"12\" nameend=\"c12\" namest=\"c1\"\u003e \u003cp\u003eSPECIFICATION of Cement\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003ctr\u003e \u003cth align=\"left\" colspan=\"6\" nameend=\"c6\" namest=\"c1\"\u003e \u003cp\u003ePHYSICAL SPECIFICATION\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colspan=\"6\" nameend=\"c12\" namest=\"c7\"\u003e \u003cp\u003eCHEMICAL SPECIFICATION\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNo.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTest\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eResult\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eFactory standard\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eINSO 389\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eTest Method\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eNO.\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eComponent\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003eResult (%)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eFactory standard\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eINSO 389\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003eTest Method\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eFineness by Blaine(cm2/gr)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e2700\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eMin2600\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eMin2600\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e390\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eSiO\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e21.11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eMax 20.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\" morerows=\"5\" rowspan=\"6\"\u003e \u003cp\u003e1692\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eAutoclave expansion\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.046\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eMax 0.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eMax 0.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e391\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eAl\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e4.48\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eMax 5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eMax 6\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"5\" nameend=\"c6\" namest=\"c2\"\u003e \u003cp\u003eSetting time\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eFe\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e3.91\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eMax 5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eMax 6\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3\u0026thinsp;\u0026minus;\u0026thinsp;1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eInitial Time (min)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e135\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eMin 70\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eMin 45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e392\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eCaO\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e63.36\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3\u0026thinsp;\u0026minus;\u0026thinsp;2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eFinal time (min)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e215\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eMax 300\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eMax 375\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e392\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eMgO\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e1.37\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eMax 2.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eMax 6\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"5\" nameend=\"c6\" namest=\"c2\"\u003e \u003cp\u003eCompressive Strength (Kg/cm2)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eSO\u003csub\u003e3\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e2.58\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eMax 2.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eMax 3\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e4\u0026thinsp;\u0026minus;\u0026thinsp;1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1 Day\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e393\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eNa\u003csub\u003e2\u003c/sub\u003eO\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.43\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e1695\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e4\u0026thinsp;\u0026minus;\u0026thinsp;2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e2 Day\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e195\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e393\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eK\u003csub\u003e2\u003c/sub\u003eO\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.48\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e4\u0026thinsp;\u0026minus;\u0026thinsp;3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3 Days\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e225\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eMin 170\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e393\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eL.O.I\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e2.85\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eMax 2.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eMax 3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c12\" morerows=\"6\" rowspan=\"7\"\u003e \u003cp\u003e1692\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e4\u0026ndash;4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e7 Days\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e325\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eMin 250\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eMin 180\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e393\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eIR\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e0.55\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003eMax 0.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003eMax1.5\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e4\u0026ndash;5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e28 Days\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e375\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eMin 350\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eMin 325\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e393\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eF.CaO\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e1.23\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003eMin 525\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"5\" nameend=\"c6\" namest=\"c2\"\u003e \u003cp\u003eHeat of hydration (cal/gr)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eC3S\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e52.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e5\u0026thinsp;\u0026minus;\u0026thinsp;1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e3 Days\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e394\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eC2S\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e21\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e5\u0026thinsp;\u0026minus;\u0026thinsp;2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e28 Days\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e394\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003eC3A\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e5.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eThe mixing ratios for TSC grouts for PA1 and PA2, as shown in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e, were identical except for the granulation of the coarse aggregate. Conventional concrete samples were mixed according to standard proportions for a cement content of 300 kg/m^3. TSC samples were meticulously crafted by placing a predefined volume of aggregates into molds, subsequently filled with grout via a vibrating table, ensuring uniform distribution and compaction, as depicted in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eThe mixture ratios in 1 m\u003csup\u003e3\u003c/sup\u003e of the grout used for PA1 and PA2.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eW/C*\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eS/C\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eC\u003c/p\u003e \u003cp\u003e(kg)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eS\u003c/p\u003e \u003cp\u003e(kg)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eW\u003c/p\u003e \u003cp\u003e(kg)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eEA/C\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e0.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e800\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e800\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e400\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.008\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003eNote: (W) water, (C) cement, (S) sand, (EA) expanding admixture.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eFollowing preparation, all specimens underwent a 28-day curing period in water, adhering to standard conditioning protocols. The compositional breakdown of materials for TSC and CC per cubic meter is outlined in Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e, highlighting the meticulous approach to mixture design.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eThe mix design for the prepared specimens in this study\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eType of concrete\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eW/C*\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eG\u003c/p\u003e \u003cp\u003e(kg)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eC\u003c/p\u003e \u003cp\u003e(kg)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eS\u003c/p\u003e \u003cp\u003e(kg)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eW\u003c/p\u003e \u003cp\u003e(kg)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePA1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1510\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e336\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e336\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e168\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePA2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1610\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e304\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e304\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e152\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.57\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1225\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e300\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e630\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e170\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"6\"\u003eNote: (W) water, (C) cement, (G) gravel, (S) sand, (EA) expanding admixture.\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eTriaxial compressive strength tests simulated the complex stress conditions typically encountered by concrete in situ. The experimental design encompassed a wide array of samples, including both dry and saturated states for PA1, PA2, and CC, ensuring a comprehensive evaluation across varied environmental conditions. The samples prepared for triaxial testing and the testing apparatus itself are showcased in Figs.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e and \u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e, respectively.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe mohr-Coulomb failure criterion was introduced to rock mechanics by Jaeger [\u003cspan citationid=\"CR70\" class=\"CitationRef\"\u003e70\u003c/span\u003e] in the year 1959 by combining the work of Mohr and Coulomb. This criterion stated that the cohesion of the material restricts shear failure across a plane. This criterion can be expressed mathematically as follows:\u003c/p\u003e \u003cp\u003eEq.\u0026nbsp;1: \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\tau =c+\\sigma tan{\\varnothing}\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e \u003cp\u003ewhere, \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\tau\\)\u003c/span\u003e\u003c/span\u003e and \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\sigma\\)\u003c/span\u003e\u003c/span\u003e are the shears and normal stresses, respectively, \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(c\\)\u003c/span\u003e\u003c/span\u003e is the apparent or inherent cohesion and \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\({\\varnothing}\\)\u003c/span\u003e\u003c/span\u003e is the angle of internal friction. The evaluation of the Mohr-Coulomb failure criteria needs to carry out many triaxial tests on rock samples at various confining pressures [\u003cspan citationid=\"CR71\" class=\"CitationRef\"\u003e71\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eFrom Mohr's circle we have:\u003c/p\u003e \u003cp\u003eEq.\u0026nbsp;2: \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\sigma = {\\sigma }_{m}-{\\tau }_{m} \\text{s}\\text{i}\\text{n}{\\varnothing} ;\\tau ={\\tau }_{m} \\text{c}\\text{o}\\text{s}{\\varnothing}\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e \u003cp\u003eWhere\u003c/p\u003e \u003cp\u003eEq.\u0026nbsp;3: \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\({\\sigma }_{m}= \\frac{{\\sigma }_{1}+{\\sigma }_{3}}{2};{\\tau }_{m}= \\frac{{\\sigma }_{1}-{\\sigma }_{3}}{2}\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e \u003cp\u003eAnd \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\({\\sigma }_{1}\\)\u003c/span\u003e\u003c/span\u003e is the maximum principal stress and \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\({\\sigma }_{3}\\)\u003c/span\u003e\u003c/span\u003e is the minimum principal stress. Therefore, the Mohr\u0026ndash;Coulomb criterion may also be expressed as\u003c/p\u003e \u003cp\u003eEq.\u0026nbsp;4: \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\({\\tau }_{m}={\\sigma }_{m} \\text{s}\\text{i}\\text{n}{\\varnothing}+\\text{c}cos{\\varnothing}\\)\u003c/span\u003e\u003c/span\u003e [\u003cspan citationid=\"CR72\" class=\"CitationRef\"\u003e72\u003c/span\u003e]\u003c/p\u003e \u003cp\u003eEmploying the Mohr-Coulomb failure criterion, the study assessed shear failure across different planes, calculating the cohesion and angle of internal friction for each concrete type under stresses of 5.5, 7.5, and 10 MPa. The utilization of Mohr circles facilitated an in-depth analysis of these parameters, exemplified in Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e, underscoring the rigorous methodological framework that underpins this research.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e"},{"header":"Results and discussion","content":"\u003cp\u003eOur triaxial compressive strength testing yielded significant insights into the performance of Two-Stage Concrete (TSC) types PA1 and PA2 compared with Conventional Concrete (CC) across various conditions. The compiled data, detailed in Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e, highlights the differential performance between the concrete types under dry and saturated conditions, with a specific emphasis on strength values, cohesion (C), and internal friction angles (ϕ).\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eThe results of the three-axis compressive strength test\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"7\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eSample name\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eTest Mod\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\({\\sigma _3}\\)\u003c/span\u003e\u003c/span\u003e(MPa)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\({\\sigma _1} - {\\sigma _3}\\)\u003c/span\u003e\u003c/span\u003e (MPa)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003e\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\({\\sigma _1}\\)\u003c/span\u003e\u003c/span\u003e(MPa)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colspan=\"2\" nameend=\"c7\" namest=\"c6\"\u003e \u003cp\u003eMohar-Columb\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eC(MPa)\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eϕ(deg)\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003ePA1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\" morerows=\"8\" rowspan=\"9\"\u003e \u003cp\u003eDry\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e43\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e48\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003e3.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003e44.9\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e50\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e57.5\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e67\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e77\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003ePA2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e47.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e52.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003e2.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003e51\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e67.32\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e74.85\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e82.04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e92.04\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eCC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e43.38\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e48.38\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003e3.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003e46.4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e54.12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e61.62\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e69.61\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e79.61\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003ePA1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\" morerows=\"8\" rowspan=\"9\"\u003e \u003cp\u003eSaturate\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e34\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e39\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003e3.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003e40.1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e48.4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e52.1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e62.1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003ePA2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e42.07\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e47.07\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003e4.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003e42.7\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e54.7\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e62.2\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e63.11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e73.11\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eCC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e40.28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e45.28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c6\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003e3.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c7\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003e43.8\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e48.33\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e55.83\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e62.79\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e72.79\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003e3.1.Strength Performance Analysis\u003c/h2\u003e \u003cp\u003eUnder dry conditions, PA2 consistently exhibited the highest strength values across all test moduli (5, 7.5, and 10 MPa), suggesting its superior structural integrity compared to PA1 and CC. Interestingly, this trend persisted even under saturated conditions, with PA2 displaying remarkable resilience. Notably, the transition from dry to saturated states resulted in a general decrease in strength for all concrete types, yet PA2's performance remained robust, underscoring its potential for applications in environments subject to moisture variation.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003e3.2.Cohesion and Internal Friction Angle\u003c/h2\u003e \u003cp\u003eCohesion values for PA1 and CC remained relatively stable across different conditions and stress levels, indicating a consistent internal binding strength. In contrast, PA2 showed a slight increase in cohesion values when dry, suggesting an enhanced interparticle bond strength in the absence of moisture. This characteristic could be attributed to the specific aggregate and grout formulation used in PA2, offering potential avenues for optimizing TSC formulations based on desired cohesion properties.\u003c/p\u003e \u003cp\u003eThe internal friction angle, a critical parameter for understanding material resistance to shear under load, was highest in PA2, especially in dry conditions. This indicates not only a superior shear resistance but also a potential for PA2 to perform well in applications requiring high shear strength. The lower ϕ values in saturated conditions across all samples highlight the impact of moisture on shear resistance, a critical consideration for construction in variable moisture environments.\u003c/p\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003e presents the internal friction angles for PA1, PA2, and CC in both dry and saturated states, revealing distinct differences in mechanical behavior under varying moisture conditions. Specifically, in the dry state, PA2 exhibits the highest friction angle at approximately 51 degrees, compared to PA1 at 44.9 degrees and CC at 46.4 degrees. This numerical superiority suggests that PA2's microstructure\u0026mdash;possibly due to a more refined aggregate interlock and optimized binder matrix\u0026mdash;provides enhanced shear resistance.\u003c/p\u003e \u003cp\u003eUnder saturated conditions, all samples show a reduction in internal friction angles, with PA2 decreasing to around 42.7 degrees, PA1 to 40.1 degrees, and CC to 43.8 degrees. The reduction in angle by about 16% for PA2, 11% for PA1, and 6% for CC from dry to saturated states underscores the impact of moisture in reducing mechanical interlock and possibly lubricating the aggregate interfaces, thereby reducing friction.\u003c/p\u003e \u003cp\u003eThis figure is pivotal in illustrating how material formulations can influence the structural integrity of concrete under environmental stress. The higher friction angles in dry conditions for PA2 indicate its suitability for high shear applications such as retaining walls and sloped structures, where shear strength is paramount. The decrease in saturated conditions highlights the need for consideration of environmental effects in design and material selection, particularly in regions prone to high moisture levels or water ingress.\u003c/p\u003e \u003cp\u003eThe quantitative analysis provided by Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e not only supports the theoretical understanding of moisture's impact on concrete but also offers a compelling argument for the advanced capabilities of TSC, especially PA2, in maintaining higher mechanical performance under adverse conditions. This data is essential for civil engineers and material scientists aiming to design more durable and resilient infrastructure capable of withstanding diverse environmental challenges.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003e explores the cohesion values of TSC types PA1, PA2, and conventional concrete CC, with a particular focus on their performance across dry and saturated states. In the dry state, PA2 demonstrates remarkably higher cohesion at 4.7 MPa compared to PA1 at 3.6 MPa and CC at 3.3 MPa. This not only highlights PA2's superior internal binding strength but also its potential for higher load-bearing capabilities and crack resistance.\u003c/p\u003e \u003cp\u003eIn saturated conditions, the cohesion values exhibit a slight decrease for all types, with PA2 showing a reduction to 4.2 MPa, PA1 to 3.5 MPa, and CC maintaining a relatively stable cohesion at 3.6 MPa. This minor decrease in cohesion for PA2 by approximately 11% from dry to saturated conditions, as opposed to a smaller 3% reduction for PA1 and a slight increase for CC, suggests that PA2's composition is optimally balanced for both dry and moist environments, albeit slightly affected by saturation.\u003c/p\u003e \u003cp\u003eThe data from this figure is crucial for understanding the implications of material choices in concrete design, particularly in contexts where environmental variability can affect structural performance. Cohesion, as a measure of the internal cementation force between particles, is a key factor in determining the durability and longevity of concrete structures. The higher cohesion values for PA2 suggest its enhanced ability to resist structural degradation over time, making it an ideal choice for critical infrastructure projects.\u003c/p\u003e \u003cp\u003eMoreover, the quantifiable decrease in cohesion under saturated conditions highlights the realistic challenges faced in engineering applications, reinforcing the need for robust material formulations. This figure thus provides a concrete basis (pun intended) for recommending PA2 in the design of structures where environmental conditions vary, ensuring that the infrastructure remains stable and functional over its intended lifespan.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003e3.3.Deviator Stress Analysis\u003c/h2\u003e \u003cp\u003eThe analysis of deviator stress under different all-round stresses shown on Figs.\u0026nbsp;8 through \u003cspan refid=\"Fig11\" class=\"InternalRef\"\u003e12\u003c/span\u003e. Figure\u0026nbsp;8 presents the deviator stress responses for PA1, PA2, and CC under varying all-round stress levels (5, 7.5, and 10 MPa) in the dry state. Specifically, PA2 shows superior stress resistance across all tested levels with stress values of 47.4 MPa, 67.32 MPa, and 82.04 MPa, respectively. This performance is contrasted with PA1, which exhibits lower stress tolerances at 43 MPa, 50 MPa, and 67 MPa, and CC, which manages 43.38 MPa, 54.12 MPa, and 69.61 MPa under the same stress conditions.\u003c/p\u003e \u003cp\u003eThis figure effectively highlights PA2's robustness, attributed to its advanced mix design, which likely enhances its load-bearing capacity and structural integrity. The quantitative superiority of PA2 suggests a higher elastic limit and potentially more effective energy dissipation properties, making it particularly suitable for structural applications where high stress resistance is required.\u003c/p\u003e \u003cp\u003eThe high performance of PA2 in a dry state indicates its potential to serve in environments where material degradation factors like moisture and temperature extremes are controlled, ensuring long-term stability and durability. This figure also serves as a compelling argument for the application of TSC in high-load bearing structures like bridges, skyscrapers, and heavy traffic pavements where superior mechanical properties are critical.\u003c/p\u003e \u003cp\u003eFigure 8- deviator stress in various all-round stresses in the dry state\u003c/p\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig8\" class=\"InternalRef\"\u003e9\u003c/span\u003e contrasts the deviator stress capabilities of PA1, PA2, and CC in a saturated state. Despite the overall reduction in deviator stress due to saturation, PA2 still manages to maintain higher stress levels at 42.07 MPa, 54.7 MPa, and 63.11 MPa across the stress levels of 5, 7.5, and 10 MPa. This is significantly better compared to PA1, which holds deviator stresses of 34 MPa, 40.9 MPa, and 52.1 MPa, and CC with 40.28 MPa, 48.33 MPa, and 62.79 MPa respectively.\u003c/p\u003e \u003cp\u003eThis figure demonstrates PA2\u0026rsquo;s resilience and its superior performance even under challenging moisture conditions, underscoring its suitability for environments with potential for moisture exposure such as underground structures, foundations in damp soils, and regions with high humidity. The data supports the narrative that PA2\u0026rsquo;s formulation, likely including moisture-resistant components or more tightly packed aggregate structures, offers enhanced durability and reliability when saturated.\u003c/p\u003e \u003cp\u003eThe relatively high performance of PA2 in saturated conditions can significantly influence construction decisions, especially in choosing materials for projects where environmental resilience is a priority. This figure also highlights the need for materials that can maintain structural integrity under variable environmental stresses, ensuring safety and reducing maintenance costs.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig9\" class=\"InternalRef\"\u003e10\u003c/span\u003e focuses on the deviator stress performance of PA1 under both dry and saturated conditions. In the dry state, PA1's stress tolerance levels are 43 MPa, 50 MPa, and 67 MPa at 5, 7.5, and 10 MPa of confining pressure, respectively. These levels drop to 34 MPa, 40.9 MPa, and 52.1 MPa when saturated, indicating a considerable decrease in structural capability due to moisture.\u003c/p\u003e \u003cp\u003eThis figure is instrumental in illustrating how PA1, while robust under normal conditions, may not be as resilient as PA2 when exposed to moisture. The decline in performance under saturation suggests potential vulnerabilities in PA1\u0026rsquo;s aggregate-binder bonding or pore structure, which could absorb and retain moisture, leading to decreased mechanical strength.\u003c/p\u003e \u003cp\u003eThe quantitative analysis provided here informs structural engineers of the limitations of using PA1 in moisture-prone environments, emphasizing the need for careful consideration of material properties in the design phase of projects. This figure also serves as a crucial educational tool, highlighting the importance of material testing under realistic environmental conditions to ensure the long-term durability and performance of construction materials.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig10\" class=\"InternalRef\"\u003e11\u003c/span\u003e showcases the outstanding deviator stress handling of PA2 in both dry and saturated states. In the dry state, PA2 withstands stresses of 47.4 MPa, 67.32 MPa, and 82.04 MPa at confining pressures of 5, 7.5, and 10 MPa, respectively. Even when saturated, PA2 maintains impressive stress levels of 42.07 MPa, 54.7 MPa, and 63.11 MPa.\u003c/p\u003e \u003cp\u003eThis figure highlights PA2's consistency and reliability under different moisture conditions, which is critical for applications where environmental factors are unpredictable. The minimal decrease in performance from dry to saturated states demonstrates PA2\u0026rsquo;s effective material composition, potentially incorporating water-resistant additives or aggregates that reduce permeability and enhance structural integrity under wet conditions.\u003c/p\u003e \u003cp\u003eThe data supports the use of PA2 in critical infrastructure, especially in regions with varying moisture levels, ensuring structural reliability and safety. The higher stress tolerance also suggests potential for PA2 in high-stress applications such as seismic zones, where materials must withstand not only high loads but also dynamic stresses.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig11\" class=\"InternalRef\"\u003e12\u003c/span\u003e displays the deviator stress responses of Conventional Concrete (CC) under both dry and saturated conditions. In the dry state, CC handles deviator stresses of 43.38 MPa, 54.12 MPa, and 69.61 MPa at 5, 7.5, and 10 MPa of confining pressures. These values decrease to 40.28 MPa, 48.33 MPa, and 62.79 MPa when saturated, illustrating a significant impact of moisture on its structural performance.\u003c/p\u003e \u003cp\u003eThis figure serves as a benchmark for comparing the enhanced properties of TSC types like PA1 and PA2 against conventional formulations. The decrease in CC's stress tolerance under saturation highlights its vulnerability to environmental conditions, emphasizing the potential benefits of opting for advanced concrete technologies like TSC for increased durability and environmental resistance.\u003c/p\u003e \u003cp\u003eThe quantitative data provided by this figure informs decision-making in material selection, particularly for projects where longevity and minimal maintenance are critical. It also underscores the importance of ongoing material innovations in the concrete industry to address the limitations observed in traditional materials, especially under adverse environmental conditions.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003e3.4.Elasticity Module Correlation\u003c/h2\u003e \u003cp\u003eThe module of elasticity, derived from uniaxial compressive tests, illustrates a direct relationship with compressive strength (σ), providing a predictive tool for estimating concrete elasticity based on known strength values (Fig.\u0026nbsp;\u003cspan refid=\"Fig12\" class=\"InternalRef\"\u003e13\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig12\" class=\"InternalRef\"\u003e13\u003c/span\u003e is instrumental in elucidating the mechanical properties of Two-Stage Concrete (TSC) types PA1 and PA2, compared to Conventional Concrete (CC). This graph presents a quantitative analysis, showing linear regression lines that depict the relationship between compressive strength (σ) and the modulus of elasticity (E) for each concrete type, effectively demonstrating how material stiffness increases with strength.\u003c/p\u003e \u003cp\u003eThe regression lines are defined as follows:\u003c/p\u003e \u003cp\u003ePA1: Eq.\u0026nbsp;6: \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(E=0.9471 \\sigma +3.3588 with {R}^{2}=0.793\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e \u003cp\u003ePA2: Eq.\u0026nbsp;5: \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(E=1.0895 \\sigma +0.7028 with {R}^{2}=0.939\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e \u003cp\u003eCC: Eq.\u0026nbsp;7: \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(E=0.409 \\sigma +10.354 with {R}^{2}=0.9661\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e \u003cp\u003eThe slope of the regression line for PA2 is notably steeper than that for PA1 and CC. This implies that PA2 not only has a higher modulus of elasticity at any given compressive strength but also gains more stiffness per unit of strength increase than PA1 or CC. This characteristic makes PA2 exceptionally suited for structural applications where deflections are critical, such as in tall structures where vertical stiffness is paramount to prevent sway and ensure stability.\u003c/p\u003e \u003cp\u003eThe high \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\({R}^{2}\\)\u003c/span\u003e\u003c/span\u003e values, especially for PA2 and CC, indicate a strong linear relationship between compressive strength and modulus of elasticity. This strong correlation means that once the compressive strength of the concrete is known, its stiffness can be predicted with high accuracy, which is invaluable in the design phase of construction projects.\u003c/p\u003e \u003cp\u003eThe relationships depicted in Fig.\u0026nbsp;\u003cspan refid=\"Fig12\" class=\"InternalRef\"\u003e13\u003c/span\u003e allow for the optimization of concrete mixes. By tweaking components such as aggregate size, the type of cement, and admixtures, manufacturers can refine their concrete to enhance both strength and stiffness. This is particularly relevant for PA2, suggesting that its mix design could be further optimized to push the boundaries of both strength and stiffness.\u003c/p\u003e \u003cp\u003eOverall, the detailed exploration of the relationships in Fig.\u0026nbsp;\u003cspan refid=\"Fig12\" class=\"InternalRef\"\u003e13\u003c/span\u003e underscores the complex interplay between material properties that are pivotal to the engineering and construction industries. It highlights how advanced materials like PA2 are setting new benchmarks in the field, offering enhanced capabilities that can significantly impact the design and execution of future construction projects.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThis comprehensive research provides an in-depth comparative analysis of the triaxial compressive strength and associated mechanical properties between Two-Stage Concrete (TSC) and Conventional Concrete (CC). Our meticulous study has revealed several intrinsic advantages of TSC, which pave the way for its augmented application in diverse construction environments. Here, we summarize the critical findings and explore their broader implications through quantitative analysis:\u003c/p\u003e \u003cp\u003e \u003cul\u003e \u003cli\u003e \u003cp\u003eOur findings provide robust evidence that aggregate size significantly impacts concrete's shear strength. Notably, TSC (PA2) with finer aggregates demonstrated enhanced performance, achieving higher shear strengths in dry conditions by up to 52.4 MPa at 5 MPa confining pressure, compared to 43 MPa for PA1 and 43.38 MPa for CC under similar conditions. This data confirms that aggregate granularity plays a vital role in optimizing concrete's mechanical properties. For TSC formulations, the strategic selection of finer aggregates not only improves shear resistance but also enhances the overall durability and load-bearing capacity of the structures.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eThe comparative analysis between TSC and CC under varied moisture conditions revealed a differential response, with all materials exhibiting diminished strength when saturated. For instance, under a confining pressure of 5 MPa, PA2 maintained a higher deviator stress tolerance in a saturated state at 42.07 MPa, compared to 40.28 MPa for CC and 34 MPa for PA1. This finding highlights the crucial role of moisture management in concrete applications, especially in environments prone to significant moisture variations. The superior performance of TSC under such conditions underscores its suitability for projects in geographically challenging regions where moisture exposure is inevitable.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eTSC demonstrated remarkable stress tolerance, which is attributed to its composition and aggregate granularity. Specifically, PA2 exhibited a superior tolerance for deviator stress reaching up to 82.04 MPa under dry conditions at a 10 MPa confining pressure\u0026mdash;significantly higher than PA1 (67 MPa) and CC (69.61 MPa). This property firmly positions TSC as a resilient choice for structural applications subjected to high loads and stresses, such as in earthquake-prone areas or for heavy infrastructure like bridges and tunnels.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eTSC's enhanced internal friction angles, as observed in our study, suggest an improved shear resistance compared to CC. For instance, PA2 showed an internal friction angle of 51 degrees in dry conditions, which was superior to PA1 at 44.9 degrees and CC at 46.4 degrees. This trait indicates TSC's potential in applications demanding high shear strength, contributing to safer and more durable structures.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eOur analysis found that TSC exhibits a higher modulus of elasticity than CC, indicating superior deformation behavior under stress. The relationship between compressive strength and modulus of elasticity for PA2 showed a steep slope with a high R\u0026sup2; value of 0.939, suggesting a reliable prediction of elasticity from known strength values. This advantageous property extends TSC's utility across a broader range of structural applications, ensuring enhanced reliability and structural integrity in load-bearing components.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eAligning with existing literature, our study reinforces the concept that smaller gravel grain size can significantly enhance concrete's mechanical resistance. This principle is particularly beneficial for the performance of TSC, offering a marked improvement in both the functional and mechanical attributes of the material.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eConsidering these insights, TSC emerges as a promising material for future construction projects, exhibiting distinct advantages in strength, durability, and environmental sustainability over traditional CC. However, despite its evident potential, the practical application, cost-effectiveness, and long-term performance of TSC require further exploration. Our study advocates for the strategic incorporation of TSC in modern construction practices, emphasizing its potential to revolutionize construction methodologies and contribute significantly to the development of sustainable and resilient infrastructure.\u003c/p\u003e \u003c/li\u003e \u003c/ul\u003e \u003c/p\u003e \u003cp\u003eIn conclusion, the study not only substantiates TSC's superior properties but also calls for a paradigm shift in how construction materials are chosen and utilized, especially in critical infrastructure projects. Further research should focus on optimizing TSC formulations for specific applications, exploring cost-effective production methods, and evaluating long-term performance to fully harness the benefits of this innovative material in the construction industry.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eData availability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets used and/or analysed during the current study available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgment\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors of the article express their appreciation and thanks to, Eng. Bahman Pirhadi and Eng. Fatemeh Omidi Moaf who have cooperated in various stages of this research.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eH. Wang and Y. 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Memoires de Mathematique et de Physique, presentes a l\u0026apos;Academie Royale des Sciences par divers savants, \u0026amp; lus dans ses assemblees, 7, 343-387.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Two-stage concrete (TSC), Preplaced aggregate concrete (PAC), Shear Strength in Concrete, Triaxial Compressive Strength Test, Mechanical Properties of Concrete, Sustainable Building Materials","lastPublishedDoi":"10.21203/rs.3.rs-4518494/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4518494/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThis study conducts a comprehensive comparative analysis of the triaxial compressive strength and associated mechanical properties between Two-Stage Concrete (TSC) and Conventional Concrete (CC). Through rigorous using triaxial test methodologies, our research quantitatively delineates TSC's mechanical superiority, promoting its broader application in diverse construction settings. Key findings reveal that TSC, particularly types with finer aggregates, demonstrates superior shear strength, achieving up to 52.4 MPa under dry conditions compared to CC's 48.38 MPa. Furthermore, TSC exhibits remarkable stress tolerance, withstanding up to 82.04 MPa, significantly outperforming CC, which manages only 69.61 MPa under similar conditions. TSC also maintains higher modulus of elasticity and internal friction angles, indicating better deformation behavior and shear resistance. Additionally, TSC shows greater resilience to moisture, suggesting its potential for use in variable moisture environments. These properties highlight TSC\u0026rsquo;s robustness for high-load applications and its suitability for infrastructure prone to environmental fluctuations. By aligning with existing literature on the benefits of finer aggregate sizes in enhancing concrete's mechanical resistance, this research underscores the strategic advantage of integrating TSC in modern construction practices, emphasizing its enhanced strength, durability, and environmental adaptability.\u003c/p\u003e","manuscriptTitle":"The Effect of Different Parameters on the Mechanical Properties of Two- Stage Concrete under Triaxial Compression","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-06-18 09:33:17","doi":"10.21203/rs.3.rs-4518494/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"editorAssigned","content":"","date":"2024-06-16T18:01:55+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2024-06-08T12:44:15+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2024-06-05T06:53:37+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2024-06-02T23:33:38+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"79f9e3f5-e039-46cb-aec4-9165514ed268","owner":[],"postedDate":"June 18th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2024-12-02T16:03:39+00:00","versionOfRecord":{"articleIdentity":"rs-4518494","link":"https://doi.org/10.1038/s41598-024-81112-8","journal":{"identity":"scientific-reports","isVorOnly":false,"title":"Scientific Reports"},"publishedOn":"2024-11-26 15:57:54","publishedOnDateReadable":"November 26th, 2024"},"versionCreatedAt":"2024-06-18 09:33:17","video":"","vorDoi":"10.1038/s41598-024-81112-8","vorDoiUrl":"https://doi.org/10.1038/s41598-024-81112-8","workflowStages":[]},"version":"v1","identity":"rs-4518494","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4518494","identity":"rs-4518494","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}