Case Studies in Construction Materials最新文献

{"title":"Synergistic effect of textile ratio, grid configuration, and hybrid mortar composition on the tensile behaviour of basalt textile reinforced composites","authors":"T.N.S. Bhagyasri,&nbsp;D. Ravi Prasad","doi":"10.1016/j.cscm.2025.e05727","DOIUrl":"10.1016/j.cscm.2025.e05727","url":null,"abstract":"<div><div>Over time, critical infrastructure deteriorates due to operational demands and extreme events, necessitating innovative approaches for rehabilitation and retrofitting. Textile-reinforced composites (TRCs) have emerged as a promising solution for strengthening and repairing existing structures. Since conventional cement composites possess limited tensile capacity, different reinforcement strategies are employed to enhance their performance. This study focuses on the development and evaluation of tensile behaviour of Basalt Textile-Reinforced Hybrid Composites (BTRC) under direct tension in accordance with ACI 434 guidelines. Thirty groups of specimens were tested to evaluate the influence of different types of mortar, including non-fibrous, mono AR glass, mono basalt, and hybrid fiber reinforced mortar, on tensile behaviour, along with the effects of textile configuration (unidirectional B5 and bi-directional B25 Fabrics) and textile reinforcement ratio. The results revealed that fiber hybridization significantly enhanced the ultimate tensile capacity from 3.45 to 5.10 MPa, an improvement of 47.83 % for the composite with B5 fabric and improved from 5.59 to 9.32 MPa, enhanced by 66.73 % for the composite with B25 Fabric compared to control specimens. Composite with B25 fabric showed the highest improvement in strength is attributed to the greater textile area and superior stiffness of yarn. The strength utilization coefficient (K) improved from 0.44 to 0.65 for B5 and improved from 0.38 to 0.64 for B25 hybrid composites compared to the reference composite, Hybrid fibers consistently enhanced the K value compared to mono and non-fibrous composites. Furthermore, increasing the number of fabric layers (textile ratio) enhanced both ultimate tensile capacity and strain, owing to improved fabric-matrix bonding. Distinct failure modes were identified: unidirectional fabrics exhibited wide single cracks that predominantly failed by fabric rupture, whereas bi-directional fabrics exhibited multiple cracking before failure. Composite reinforced with Hybrid fiber (B25–3-A10HY) showed finer crack patterns, with the number of cracks increasing from 4 to 6 and crack spacing reducing from 6 to 3 cm compared to the reference composite (B25–3-A0) due to improved ductility, and a stronger matrix–fabric bond. Based on regression analysis of the experimental results, an empirical formula was developed to calculate the ultimate tensile strength of BTRC based on the strength utilization coefficient (K), considering the combined effects of textile reinforcing ratio and short fibers, showing good agreement with experimental results, thereby providing valuable insight into the tensile behaviour of textile-reinforced composites for retrofitting applications. Future studies are recommended to investigate the durability, long-term performance, and large-scale structural applicability of BTRC systems to further validate and extend the proposed findings.</div></div>","PeriodicalId":9641,"journal":{"name":"Case Studies in Construction Materials","volume":"24 ","pages":"Article e05727"},"PeriodicalIF":6.6,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145921563","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing tensile strength and microstructural properties of solidified high-moisture dredged sediment through solid waste-based binder stabilization and basalt fiber reinforcement","authors":"Hongwei Wang ,&nbsp;Jiahui Zhang ,&nbsp;Longjun Dong ,&nbsp;Rachid Zentar ,&nbsp;Ying Shi ,&nbsp;Daoyuan Sun","doi":"10.1016/j.cscm.2025.e05752","DOIUrl":"10.1016/j.cscm.2025.e05752","url":null,"abstract":"<div><div>The study of materials with good mechanical properties for backfilling Urban Underground Spaces (UUS), such as abandoned underground spaces and ground subsidence, has important practical significance for achieving urban safety. A binder developed with solid waste materials was employed to solidify dredged sediment, transforming it into a Liquefied Stabilized Backfill Material (LSBM) for UUS. This study investigates the reinforcing effect of Basalt Fibers (BF) on the Splitting Tensile Strength (STS) behavior of solidified dredged sediment treated with a waste-based binder. A comprehensive experimental program was conducted to assess the influence of BF content, BF length, curing time, initial moisture content, and binder dosage on both STS and stress-strain responses. The results indicate that the optimal BF contents for maximizing STS at 3, 7, and 28 days were 0.1%, 0.1%, and 0.2%, respectively. Meanwhile, the corresponding STS values were 182.20 kPa, 191.98 kPa, and 242.74 kPa, representing STS increases of 120.9%, 65.2%, and 31.3% compared to the solidified sediment without BF. A fiber length of 3 mm yielded the best reinforcing effect on the tensile strength behavior of LSBM, with the STS reaching peak values of 104.47 kPa, 183.12 kPa, and 260.89 kPa at the curing times of 3, 7, and 28 days, respectively. Moreover, BF incorporation significantly improved the ductility of the solidified matrix. A regression model with a high coefficient of determination (R²=0.947) was developed, enabling effective analysis and estimation of STS from the given parameters under comparable conditions. Additionally, a strong linear relationship between the STS and Unconfined Compressive Strength (UCS) for the LSBM samples was established. Microstructural analysis revealed that the BF enhances tensile performance by increasing interfacial friction and filling pores via associated hydration products, thereby facilitating a broader stress distribution within the dense matrix. Additionally, a simplified economic and environmental benefit analysis demonstrated that per 100 kPa of STS, the 28d solidified sediment with 0.2% BF exhibited a 7.3% reduction in cost and a 15.7% reduction in CO₂ emissions per ton compared with the solidified sediment backfill material without BF. Overall, the findings of this study demonstrate that BF-reinforced, waste binder-treated dredged sediment presents a technically viable and environmentally sustainable solution for UUS backfilling.</div></div>","PeriodicalId":9641,"journal":{"name":"Case Studies in Construction Materials","volume":"24 ","pages":"Article e05752"},"PeriodicalIF":6.6,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145921752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of Sugarcane Bagasse Ash on the sustainable performance of hot-mix asphalt: A case study of experimental and numerical analysis","authors":"Udeme Udo Imoh ,&nbsp;Adeyemi Oluwaseun Adeboje ,&nbsp;Ebunlomo Ruth Adekola ,&nbsp;Rauf Hassan ,&nbsp;Majid Movahedi Rad","doi":"10.1016/j.cscm.2026.e05769","DOIUrl":"10.1016/j.cscm.2026.e05769","url":null,"abstract":"<div><div>The growing demand for sustainable road infrastructure has intensified the interest in alternative mineral fillers that reduce natural resource consumption and environmental impacts. This study investigates the use of Sugarcane Bagasse Ash (SBA), an abundant agricultural by-product in sub-Saharan Africa, as a partial replacement for conventional mineral fillers in hot-mix asphalt (HMA). Unlike previous studies that considered SBA primarily as a minor additive, this study provides a systematic evaluation across a wide replacement range (0–16 %), combined with experimental testing and numerical validation. Marshall and indirect tensile strength (ITS) tests were conducted on HMA mixtures produced using locally sourced Nigerian aggregates and 60/70 penetration-grade bitumen. A three-dimensional finite element model (FEM) of the ITS configuration was developed to corroborate the experimental response and identify stress concentration zones. results indicate that SBA improves both mechanical and volumetric performance within an optimal replacement range of 6–10 %, with peak performance of approximately 8 % SBA. Within this range, Marshall stability increased from 7.6 kN to 9.0 kN, the Marshall quotient reached 3.3 kN/mm, bulk density increased to 2.51 g/cm³, and air voids decreased from 4.9 % to 3.5 %, remaining within standard design limits. Microstructural analyses confirmed the predominance of amorphous silica and porous SBA morphology, which promoted enhanced filler–binder interactions and mixture densification. FEM predictions of peak tensile stress agreed with laboratory ITS results within 10 % and successfully reproduced observed crack initiation zones. Excessive SBA content (&gt; 10 %) led to reduced stability and density owing to over-filling effects. The findings demonstrate that 6–10 % SBA is a technically viable and sustainable filler replacement for HMA, particularly in sugarcane-producing regions, offering improved performance alongside waste valorization and reduced reliance on quarry-derived fillers.</div></div>","PeriodicalId":9641,"journal":{"name":"Case Studies in Construction Materials","volume":"24 ","pages":"Article e05769"},"PeriodicalIF":6.6,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145921819","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on sulphate erosion resistance of damaged concrete specimens reinforced with sprayed glass fibre-epoxy mortar","authors":"Jianhui Si ,&nbsp;Hanyue Li ,&nbsp;Shibo Qiao ,&nbsp;Xiaoyu Niu ,&nbsp;Junpeng Ju ,&nbsp;Lizhe He ,&nbsp;Junlin Xiang","doi":"10.1016/j.cscm.2026.e05768","DOIUrl":"10.1016/j.cscm.2026.e05768","url":null,"abstract":"<div><div>Sulfate erosion has been identified as a primary factor contributing to the reduction in durability of concrete, particularly in the salt lakes of western China and the saline-alkali regions of North China. Consequently, enhancing the sulfate erosion resistance of damaged concrete structures is of paramount importance for prolonging the service life of building structures. The paper goes on to address the drawbacks of existing reinforcement methods, such as complex construction processes and the tendency of coatings to age and peel off, requiring frequent replacement. The study proposes the use of sprayed glass fibre-epoxy mortar reinforcement layers. The present study aims to elucidate the reinforcement mechanism through performance evolution studies of three groups of specimens (unreinforced undamaged concrete specimens, reinforced undamaged concrete specimens, and reinforced damaged concrete specimens) under 5 % Na₂SO₄ solution corrosion and coupled dry-wet cycling environments. The findings indicate that following 120 cycles in a sulfate erosion-dry-wet alternating multi-cycle coupled environment, there was a 66 % decrease in the mass loss rate of the reinforced damaged concrete specimen, from 0.62 % to 0.21 %, while the compressive strength increased from 19.87 MPa to 25.93 MPa, an increase of 23.37 %, in comparison to the unreinforced undamaged concrete specimen. The application of a glass fibre-epoxy mortar reinforcement layer around damaged concrete has been shown to enhance the performance of the concrete in terms of its resistance to sulphate, thus demonstrating a positive effect on the concrete's capacity to resist sulphate.</div></div>","PeriodicalId":9641,"journal":{"name":"Case Studies in Construction Materials","volume":"24 ","pages":"Article e05768"},"PeriodicalIF":6.6,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145921822","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Calcium leaching resistance and mechanism of early-age mortar with combined incorporation of glass powder and nano-silica under leaching conditions","authors":"Yuyang Liu ,&nbsp;Taifeng Zhong ,&nbsp;Wei Li ,&nbsp;Yeda Li ,&nbsp;Liping Jin ,&nbsp;Likang Qiu ,&nbsp;Liangjun Gu ,&nbsp;Yueyue Ling","doi":"10.1016/j.cscm.2025.e05681","DOIUrl":"10.1016/j.cscm.2025.e05681","url":null,"abstract":"<div><div>After application, shotcrete is immediately subjected to erosion by surrounding rock water, and calcium leaching is prone to occur in early-age concrete under leaching conditions. The combined incorporation of glass powder (GP) and nano-silica (NS) is expected to enhance the calcium leaching resistance of shotcrete; however, the improvement effect and mechanism of GP-NS incorporation in early-age concrete under leaching conditions remain unclear. In this study, leaching tests were conducted on early-age mortar specimens with GP-NS incorporation. Calcium leaching resistance was analyzed through measurements of leached calcium, soluble calcium, and leaching depth, and its mechanism was elucidated using TGA, MIP, SEM, and EDS. Finally, compressive strength tests were conducted to determine the optimal mix ratio. Results show that GP-NS incorporation improves the calcium leaching resistance of early-age mortar throughout the 28d leaching process, with the concentration of leached calcium ions in the 40 % GP-9 % NS group being 30.97 % lower than that of the control group at 28d. The dilution and pozzolanic effects of GP and NS act synergistically to reduce soluble calcium sources. Compared with the control group, the 40 % GP-9 % NS group exhibited a 68.66 % reduction in soluble calcium per unit mass at 28d, and the 25 % GP-9 % NS group showed a 6.04 % lower total CH content percentage. The incorporation of NS mitigates the deterioration of pore structure in early-age mortar under leaching conditions induced by GP, thereby blocking calcium ion leaching pathways. The porosity of the 25 % GP-9 % NS group was 7.11 % lower than that of the 25 % GP group. The activity stages of the externally incorporated materials are effectively connected in sequence: NS's secondary hydration occurs from 7 to 14d, while the pozzolanic effect of GP develops from 14 to 28d. The incorporation of NS effectively compensates for the deficiency in early strength of GP alone. The 40 % GP-9 % NS group showed a 34.75 % improvement in compressive strength at 7 d compared to the 40 % GP group. Under leaching conditions, the optimal mix ratio for the GP-NS incorporation is 25 % GP-6 % NS. The calcium leaching process increases mortar porosity, with pore morphology evolution characterized by pore enlargement, pathway extension, and the formation of numerous ink-bottle pores due to local pitting corrosion. These findings provide a reference for mitigating calcium leaching in tunnel shotcrete and promoting the resource utilization of glass solid waste.</div></div>","PeriodicalId":9641,"journal":{"name":"Case Studies in Construction Materials","volume":"24 ","pages":"Article e05681"},"PeriodicalIF":6.6,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145788587","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hyperspectral remote sensing for characterizing asphalt binders, mastics, and mixtures under aging conditions","authors":"Vatsal Dharmeshkumar Patel ,&nbsp;Ankush Kumar ,&nbsp;Rishikesh Bharti ,&nbsp;Rajan Choudhary","doi":"10.1016/j.cscm.2025.e05683","DOIUrl":"10.1016/j.cscm.2025.e05683","url":null,"abstract":"<div><div>Asphalt aging is a complex process that involves rheological, chemical, and mechanical changes affecting pavement durability. This research examines the aging behavior of asphalt binders, mastics, and mixtures using Viscosity Grade 30 (VG30), polymer-modified (PMB), and crumb rubber-modified (CRMB) binders. A multi-technique approach integrated rheological (MSCR, LAS), chemical (FTIR), and mechanical (IDEAL-CT) analyses with the hyperspectral remote sensing, under unaged (UA), short-term (STA), and long-term (LTA) aging conditions. RTFO/TFO and PAV were used to simulate STA and LTA for binders and mastics, and a forced-draft oven for mixtures. Results showed a 35–45 % increase in aging degree from short-term to long-term exposure across all materials, with VG30-based samples being the most vulnerable, while PMB and CRMB demonstrated enhanced oxidative stability. Hyperspectral similarity scores exhibited a strong negative correlation with both the rheological indices (R = −0.77 to −0.81) and chemical indices (R = −0.72 to −0.79), as well as a strong positive correlation (R = 0.77) with mechanical indices. These findings demonstrate the potential of hyperspectral sensing as a rapid, non-destructive tool for asphalt aging assessment. This integrated assessment furthers understanding of material behavior and advanced pavement performance monitoring.</div></div>","PeriodicalId":9641,"journal":{"name":"Case Studies in Construction Materials","volume":"24 ","pages":"Article e05683"},"PeriodicalIF":6.6,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145735771","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design and evaluation of restoration strategies for a fractured ancient stone stele (618–907 CE): Experimental characterization, numerical simulation and theoretical analysis","authors":"Zhuofeng Chen ,&nbsp;Chen Wu ,&nbsp;Wanqian Feng ,&nbsp;Pengcheng Zhou ,&nbsp;Jing Cao ,&nbsp;Wenqiang Dong ,&nbsp;Mara Camaiti ,&nbsp;Yijian Cao","doi":"10.1016/j.cscm.2025.e05657","DOIUrl":"10.1016/j.cscm.2025.e05657","url":null,"abstract":"<div><div>The rational and non-destructive design of restoration strategies for large and precious stone artworks remains a great challenge worldwide. To study the restoration of a severely fractured ancient stone stele, experimental characterization of the physicochemical and mechanical properties, numerical and theoretical analyses of virtually restored models were conducted. In the study, five different restoration methods were proposed, combining epoxy adhesive with various types of pin materials. Based on the experimental characterization, the basic parameters for model creation were obtained. Through the in-depth analysis of the simulation results (e.g., the first principal stress, displacement and the Rankine safety factor), the most effective method was identified, i.e., a PTFE pin coated with epoxy adhesive applied to the central fracture, with the epoxy adhesive also applied to the fractured surface. Results also reveal that epoxy adhesive applied to the fracture effectively enhances the load-bearing capacity of the stele, achieving the fundamental aim of the restoration practice. The pin can restrict the displacement and reduce the deformation of the entire structure effectively. Under the transversal loads of 4000 N/m² applied to the rear surface (L_y) of the stele and of 16000 N/m² applied to the right surface (L_x) of the stele, the maximum displacement of the models with the pin and adhesive applied was only 16 % of the model without pin application. Whereas the pin also induces localized stress concentration. Furthermore, coating the pin with adhesive materials can both moderately improve the load-bearing capacity and reduce the deformation of the model. This study facilitates the non-destructive design of repair strategies for stone-built heritage, and also broadens the advanced application of material sciences, engineering mechanics in heritage conservation.</div></div>","PeriodicalId":9641,"journal":{"name":"Case Studies in Construction Materials","volume":"24 ","pages":"Article e05657"},"PeriodicalIF":6.6,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145735769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluating glass powder substitution for 3D printed concrete: Effects on thermal properties and embodied carbon","authors":"Amardeep Singh ,&nbsp;Jingting Sun ,&nbsp;Deng Qi ,&nbsp;Md Jaynul Abden ,&nbsp;Yi Yi Zhou ,&nbsp;Zhenhua Duan ,&nbsp;Vivian W.Y. Tam","doi":"10.1016/j.cscm.2026.e05786","DOIUrl":"10.1016/j.cscm.2026.e05786","url":null,"abstract":"<div><div>The construction industry faces increasing pressure to reduce its environmental footprint through improved materials and construction practices. This study investigates the use of ultra-fine glass powder (UFGP) as a partial cement replacement in reactive powder concrete (RPC) for 3D-printed concrete (3DPC), focusing on thermal performance and embodied carbon reduction. Six mix designs with UFGP replacement levels up to 25 % were evaluated. Experimental results show that substituting 5 % of cement with UFGP reduces thermal conductivity by 10.9 %, enhancing the material’s insulation capacity. EnergyPlus simulations for a residential building in Shanghai indicate a potential annual energy savings of 2.6 MJ/m² (4.85 %) with 5 % UFGP-enhanced concrete, arising from the synergistic effects of reduced thermal conductivity and increased thermal mass. Although the high binder content (1000 kg/m³) remains a limitation of current 3DPC technology, partial cement replacement with UFGP presents a viable strategy for lowering embodied carbon while improving thermal performance. These results demonstrate the potential of UFGP to advance next-generation sustainable construction by enhancing energy efficiency and reducing embodied carbon in 3D-printed concrete applications. However, further investigation is needed to validate performance across a wider range of environmental and structural conditions.</div></div>","PeriodicalId":9641,"journal":{"name":"Case Studies in Construction Materials","volume":"24 ","pages":"Article e05786"},"PeriodicalIF":6.6,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145973253","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prediction of ultrasonic pulse velocity and physicochemical properties of rice husk ash concrete exposed to elevated temperatures and post-fire curing","authors":"Ali Nazari,&nbsp;Vahab Toufigh","doi":"10.1016/j.cscm.2025.e05715","DOIUrl":"10.1016/j.cscm.2025.e05715","url":null,"abstract":"<div><div>The novelty of this study is its evaluation of the physicochemical properties and non-destructive testing performance of concrete containing rice husk ash (RA) subjected to post-heating curing. The study examines temperatures of 300°C, 500°C, and 700°C. Post-heating curing was performed in water and in air for 28 and 56 days. Ultrasonic pulse velocity (UPV), X-ray diffraction (XRD), scanning electron microscopy (SEM), and thermogravimetric (TG)/differential thermogravimetric (DTG) analysis were determined to evaluate thermal damage and recovery mechanisms. Predictive relationships between UPV and the outcomes of destructive tests were established, allowing the condition of the concrete to be estimated without relying solely on destructive methods. The high R-squared values, ranging from 0.83 to 0.98, confirm that UPV is a reliable indicator of thermal damage and recovery. Physicochemical analyses highlighted the rehydration and pozzolanic activity of RA, with 8 % RA recovering 36.7 % compressive strength after 56 days of water re-curing. A statistical optimization using the Taguchi method and ANOVA was additionally performed to identify the most effective parameters influencing strength recovery. Post hoc Tukey HSB was used to compare RA levels and temperatures. Optimization results highlighted that 8 % RA content provided the most significant improvement in recovery behavior, particularly under water re-curing conditions. Finally, a life cycle assessment (LCA) was conducted to evaluate the environmental impacts of the studied concrete mixtures. This assessment showed that incorporating RA significantly lowered environmental impacts, reducing global warming potential by 21.3 % and resource depletion by 24.8 %.</div></div>","PeriodicalId":9641,"journal":{"name":"Case Studies in Construction Materials","volume":"24 ","pages":"Article e05715"},"PeriodicalIF":6.6,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145921440","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental investigation and numerical study on chloride diffusion coefficient of long-term fly ash concrete","authors":"Jian Zhang ,&nbsp;Wen-bing Song ,&nbsp;Hai-long Wang ,&nbsp;Zhi-wei Chen ,&nbsp;Qing-feng Liu ,&nbsp;Feng-yan Qi","doi":"10.1016/j.cscm.2025.e05745","DOIUrl":"10.1016/j.cscm.2025.e05745","url":null,"abstract":"<div><div>Owing to the specific hydration characteristics of fly ash, reasonable replacement of fly ash in concrete can optimize the microstructure of concrete and significantly enhance its resistance to chloride ion penetration. In this paper, both experimental investigations and numerical simulations are performed to study the variation regulation of the chloride diffusion coefficient in fly ash concrete. In the experiments, the influence of the water to binder ratio, aggregate volume fraction, fly ash replacement rate, and curing age on the chloride diffusion coefficient is studied. The experimental results show that, as the water to binder ratio increases or aggregate volume fraction decreases, the chloride diffusion coefficient of concrete increases. When the curing age is 60, 240, and 720 d at a fly ash replacement rate of 30 %, the chloride diffusion coefficients are 30.2 %, 33.5 %, and 51.1 % lower than that at a fly ash replacement rate of 10 %, respectively. For fly ash replacement rates of 10 %, 20 %, and 30 %, the average decreasing rates of the chloride diffusion coefficient at different aggregate volume fractions and water to binder ratios account for 93.8 %, 93.5 %, and 93.6 % of the total decreasing rates, for a curing-age range from 28 to 540 d. In the numerical simulations, the microstructure of blended system is constructed according to the hydration kinetics model. The reliability of the hydration model is verified by the experimental results. The mesostructure of three-phase concrete is constructed by increasing the scale. A continuous-based random walk method is proposed and applied to the blended bulk paste and concrete scale by scale to obtain the corresponding chloride diffusion coefficients. The reliability of the numerical simulation method is verified by 18 groups of experimental results. The simulation results indicate that the average reduction in the chloride diffusion coefficients when the curing age increases from 720 to 1800 d contributes merely 1.9 %, 2.0 %, and 2.2 % of the total reduction observed over an extended period from 28 to 1800 days, for fly ash replacement rates of 10 %, 20 %, and 30 %, respectively.</div></div>","PeriodicalId":9641,"journal":{"name":"Case Studies in Construction Materials","volume":"24 ","pages":"Article e05745"},"PeriodicalIF":6.6,"publicationDate":"2026-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145921562","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}