Case Studies in Construction Materials最新文献

{"title":"Chemical and thermal stabilization of gypseous loess soils: Comparative study of natural environmental friendly materials (zeolite and gypsum) and cement","authors":"Erfan Sadeghi ,&nbsp;Mohammad Reza Nikudel ,&nbsp;Shahram Ghasemi ,&nbsp;Narges Bayat","doi":"10.1016/j.cscm.2025.e04945","DOIUrl":"10.1016/j.cscm.2025.e04945","url":null,"abstract":"<div><div>Gypseous loess soils exhibit complex and unpredictable behavior under environmental moisture variations, posing significant challenges in geotechnical engineering. Chemical stabilization and thermal stabilization are commonly used methods for stabilizing gypseous loess soils. Common materials such as cement and lime are expensive and unsustainable. This study investigates the stabilization of gypseous loess soils by zeolite as an environmentally friendly stabilizer to reduce carbon footprint and cement as a common stabilizer. Two distinct methods were employed to activate zeolite: sodium hydroxide and co-activation with cement. Gypseous soils were stabilized by 3 %, 5 %, 7 %, and 10 % stabilizing agents, and the performance of the stabilized soils was subsequently assessed under various environmental conditions such as wetting-drying by unconfined compressive strength, P-wave velocity, XRD, and SEM/EDAX tests. The results reveal that zeolite exhibits effective soil stabilization for low and high gypsum content, unlike cement, which demonstrates limitations in stabilizing soils. Cement stabilization leads to the formation of ettringite minerals, and increasing cement content increases ettringite formation. In contrast, stabilization with zeolite prevents the formation of ettringite minerals and enhances soil strength as the zeolite dosage increases. However, when zeolite partially replaces cement, soil strength improves up to a substitution level of 30 %; beyond this level, higher substitution ratios lead to a decrease in strength. The absence of ettringite in zeolite-stabilized soils, along with zeolite's unique ability to limit the leaching of dissolved gypsum, explains its superior performance during wetting-drying cycles compared to cement. In thermal stabilization, an increase in the percentage of gypsum present in the sample leads to an increase in uniaxial compressive strength. The study revealed that zeolite could effectively improve gypseous soil's properties and exhibit unique advantages over conventional cement stabilization, which is not an environmentally friendly and sustainable method. This study introduces a novel application of zeolite as a dual-activated, eco-friendly stabilizer for gypseous loess soils, offering a sustainable and technically effective alternative to traditional cement-based methods.</div></div>","PeriodicalId":9641,"journal":{"name":"Case Studies in Construction Materials","volume":"23 ","pages":"Article e04945"},"PeriodicalIF":6.5,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144480939","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 study and machine learning prediction on compressive strength of industrial waste- solidified marine soft soil under dry-wet cycles","authors":"Yi-dan Sun ,&nbsp;Chao Li ,&nbsp;Qiu-yang Bi ,&nbsp;Jia-wei Li ,&nbsp;Jin-liang Zhang ,&nbsp;Xiao-yu Lu ,&nbsp;Yu Yang","doi":"10.1016/j.cscm.2025.e04943","DOIUrl":"10.1016/j.cscm.2025.e04943","url":null,"abstract":"<div><div>The rapid development of infrastructure in coastal regions has led to the deterioration of soil mechanical properties due to dry-wet (D-W) cycles, which significantly affects the durability of engineering projects. While most previous studies have focused on the impact of curing agents on the mechanical properties of marine soft soil (MSS), a systematic framework for predicting the strength of stabilized materials under D-W cycles is still lacking. To address this gap, this study utilizes blast furnace slag (GGBS), fly ash (FA), and lime in combination to improve MSS. A database containing 624 Unconfined compressive strength (UCS) data points was established to study the strength characteristics and curing mechanism of solidified Marine silt (LGF-MSS) under D-W cycles, and the optimal content of curing agent was determined. Using the XGBoost machine learning framework, optimization algorithms including the Whale Optimization Algorithm, Particle Swarm Optimization, Sparrow Search Algorithm, Grey Wolf Optimization, and Firefly Optimization Algorithm were applied to develop a UCS prediction model under D-W conditions. The SSA-XGBoost model achieves optimal performance in UCS prediction, with a coefficient of determination (R²) of 0.9786 on the test set. In addition, the study provides the importance of curing age, LGF content, number of cycles, degree of compaction, and drying temperature by using correlation analysis, sensitivity analysis, and SHapley Additive exPlanations (SHAP). The developed high-precision prediction model effectively predicts the strength of LGF-MSS under D-W cycles, offering strong technical support and decision-making references for related engineering practices.</div></div>","PeriodicalId":9641,"journal":{"name":"Case Studies in Construction Materials","volume":"23 ","pages":"Article e04943"},"PeriodicalIF":6.5,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144329931","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":"Phased array ultrasonic and deep learning based internal defect detection in underwater concrete bridge structures","authors":"Weihao Sun ,&nbsp;Shitong Hou ,&nbsp;Gang Wu ,&nbsp;Zhishen Wu ,&nbsp;Wen Xiong ,&nbsp;Jian Zhang","doi":"10.1016/j.cscm.2025.e04946","DOIUrl":"10.1016/j.cscm.2025.e04946","url":null,"abstract":"<div><div>Underwater concrete structures, which are critical load-bearing components in water-crossing bridges, are often prone to internal defects that undermine their long-term integrity. Traditional inspection methods, which mainly focus on surface defects, fall short in detecting internal structural issues, creating a significant gap in maintenance and safety assessments. This study proposes a phased array ultrasonic testing (PAUT) and deep learning based internal defect detection method in underwater concrete bridges. First, a new underwater PAUT device is developed, incorporating non-local means filtering to reduce noise and enhance ultrasonic imaging quality. Second, a small-scale dataset of ultrasonic images depicting internal defects in underwater concrete is created, and StyleGAN2-ADA was employed for effective data augmentation, addressing the challenge of limited data availability. To further improve defect detection, an enhanced SAM-based method is introduced, utilizing both serial and parallel depth-wise adapter fine-tuning strategies, which significantly boost the model's adaptability to complex underwater ultrasonic imaging tasks. Additionally, a pyramid-module-based self-generating prompt encoder is developed to optimize feature extraction and reduce manual intervention. Experimental results on both laboratory specimens and real-world underwater bridge piers demonstrate the superior performance of this method. The detection model achieves an Intersection over Union (IoU) score of 0.772—an improvement of 4.49 % over the baseline SAM model—and outperforms other approaches in precision, recall, and F1-score. This research presents a robust, efficient, and scalable solution for internal defect detection in underwater concrete bridge structures, with strong potential for real-world applications in structural health monitoring.</div></div>","PeriodicalId":9641,"journal":{"name":"Case Studies in Construction Materials","volume":"23 ","pages":"Article e04946"},"PeriodicalIF":6.5,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144321630","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":"Iron tailing powder in cement-based composites: Evaluating filling effect from particle-size distribution","authors":"Mingjing Yang,&nbsp;Jianheng Sun,&nbsp;Jing Yuan,&nbsp;Hongbin Li,&nbsp;Da Xu,&nbsp;Ruolan Zhang,&nbsp;Xinrui Ma","doi":"10.1016/j.cscm.2025.e04919","DOIUrl":"10.1016/j.cscm.2025.e04919","url":null,"abstract":"<div><div>Iron tailings, a significant hazardous waste, can be put to use as mineral admixtures in concrete, but the mechanism by which they function requires elucidation. In this study, we define a filling-effect coefficient <em>δ</em> for iron tailing powder (ITP) based on the Horsfield and Andreasen closest-packing theories. Four intervals of the particle size are selected to show how the distribution of ITP affects the pore structure of cement-based composites (CBCs). Experimental measurements of the activity of ITP show that by using <em>δ</em>, the activity indices of ITPs with different fineness values can be calculated without time-consuming mortar tests. Our analysis indicates that ITP particle sizes &lt; 5 µm are essential for the filling effect. However, the contribution of the filling effect to the activity index is limited: Excessive increase in the fineness of ITP does not further enhance their activity. The overall correlation coefficient between <em>δ</em> and the 28 d activity index of ITP with different fineness values is 0.9076. An evaluation formula of the activity index of ITP is established to quantitatively calculate the activity index of ITP with different fineness without mortar test.</div></div>","PeriodicalId":9641,"journal":{"name":"Case Studies in Construction Materials","volume":"23 ","pages":"Article e04919"},"PeriodicalIF":6.5,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144321631","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":"Optimization and utilization of air-entrained recycled brick aggregate concrete under freeze-thaw environment","authors":"Muhammad Atasham ul haq ,&nbsp;Peng Wang ,&nbsp;Yaocheng Wang ,&nbsp;Hongzhi Cui ,&nbsp;Muhammad Tahir ,&nbsp;Fuyuan Gong ,&nbsp;Weiwen Li","doi":"10.1016/j.cscm.2025.e04941","DOIUrl":"10.1016/j.cscm.2025.e04941","url":null,"abstract":"<div><div>Utilizing recycled brick aggregate (RBA) offers a sustainable solution to the environmental challenges posed by construction and demolition waste (CDW). However, the high water absorption and porosity of RBA accelerate freeze-thaw (FT) damage, leading to significant deterioration of both the aggregate and the concrete matrix, which compromises structural integrity. While air-entrainment has proven effective for natural and recycled concrete aggregate concrete, its application to recycled brick aggregate concrete (RBAC) remains unexplored. This study investigates the effectiveness of air-entrainment in enhancing the FT resistance of RBAC. Twelve air-entrained RBAC mixtures with varying w/c ratios (0.55, 0.45, and 0.35) and RBA substitution levels (0 %, 25 %, 50 %, and 100 %) were prepared and subjected to 300 rapid FT cycles. The results showed that RBA has a detrimental effect on the FT resistance of RBAC despite air-entrainment as evidenced by the increased mass loss, reduced RDME, and reduction in compressive strength. However, the combination of air-entrainment with low w/c ratio effectively moderated internal deterioration caused by ice expansion during FT cycling. Mercury intrusion porosimetry (MIP) analysis showed similar alteration in pore size distribution between the 0.35A-RBA-0 and 0.35A-RBA-100 specimen after FT cycling, while RBAC specimens with 0.45 and 0.55 w/c ratio showed significant expansion of mesopores and macropores (harmful pores &gt;100 nm). X-ray computed tomography (XCT) analysis confirmed that air-entrainment preserved the mortar matrix from cracking despite localized RBA cracking at low w/c ratio. The developed FT damage model confirmed up to 46 % reduction in service life of RBAC compared to NAC, depending on w/c ratio. Therefore, it is recommended to limit the RBA content to 50 % while maintaining low w/c ratio at or below 0.45, particularly in cold regions where FT resistance is critical. These findings establish guidelines for optimizing RBAC mix design under cold climates, advancing sustainability and promoting circular economy practices in the construction sector.</div></div>","PeriodicalId":9641,"journal":{"name":"Case Studies in Construction Materials","volume":"23 ","pages":"Article e04941"},"PeriodicalIF":6.5,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144313461","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":"Evaluation of compressive strength of eco-friendly cementitious composites incorporating waste oyster shells under sodium chloride solution exposure","authors":"Jinwoong Kim,&nbsp;Inyeong Cha,&nbsp;Byungkyu Jo,&nbsp;Heeyoung Lee","doi":"10.1016/j.cscm.2025.e04944","DOIUrl":"10.1016/j.cscm.2025.e04944","url":null,"abstract":"<div><div>The development of the marine industry and the continuous increase in oyster production have caused the accumulation of large quantities of waste oyster shells, with only a small portion being recycled. Unrecycled waste oyster shells cause environmental problems, produce odors, and harm marine ecosystems. Simultaneously, aggregates such as sand are in high demand in the construction industry. Waste oyster shells, primarily comprising calcium carbonate (CaCO₃), have similar material characteristics to sand and can be used as a sand substitute. In this study, oyster shell cementitious composites were produced to assess the potential of waste oyster shells as a sand replacement. The experimental parameters included the use of admixtures, curing in either fresh water or sodium chloride solution, and various curing durations. The specimens were cured for 91 days in fresh water and 30, 60, or 91 days in sodium chloride solution. Nine oyster shell cementitious composite specimens measuring 50 mm × 50 mm × 50 mm were fabricated for each experimental condition, resulting in a total of 144 specimens. When cured in sodium chloride solution, the compressive strength decreased as the curing time increased, while the compressive strengths cured in fresh water and sodium chloride solution for 91 days were 38.8 and 34.55 MPa, respectively. Thus, the specimens cured in sodium chloride solution retained more than 80 % of the strength of those cured in fresh water. Therefore, waste oyster shells can serve as an eco-friendly construction material and are a viable alternative to sand.</div></div>","PeriodicalId":9641,"journal":{"name":"Case Studies in Construction Materials","volume":"23 ","pages":"Article e04944"},"PeriodicalIF":6.5,"publicationDate":"2025-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144329932","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":"Shear behavior of environmentally friendly rubberized RC beams externally strengthened with side-bonded prefabricated SHCC plates","authors":"Mohamed Ghalla ,&nbsp;Mohamed H. El-Naqeeb ,&nbsp;Weiwen Li ,&nbsp;Peng Wang ,&nbsp;Walid Mansour ,&nbsp;Taher A. Tawfik","doi":"10.1016/j.cscm.2025.e04936","DOIUrl":"10.1016/j.cscm.2025.e04936","url":null,"abstract":"<div><div>This research proposes a sustainable solution for discarded tire disposal by repurposing rubber as a sand replacement in concrete mixtures for reinforced concrete (RC) beams. Furthermore, it examines the strengthening of rubberized beams using prefabricated strain-hardening cementitious composite (SHCC) plates to mitigate potential reductions in ultimate load or ductility caused by rubber incorporation in the concrete mixture. An experimental program was designed, consisting of 16 half-scale RC beams with shear deficiencies tested under three-point loading. The program investigates the effect of replacing sand with recycled rubber at proportions of 10 %, 30 %, and 50 %. Additionally, it examines the arrangement of the strengthening plates, either vertical or inclined at a 45° to the beam axis, as well as the fixation method, using either epoxy alone or a combination of epoxy and 10 mm steel anchors. The results indicate that vertical and inclined SHCC plates, fixed with epoxy alone, enhanced the ultimate load of rubberized beams containing 10 % rubber by 5 % and 16 %, respectively, compared to the reference beam cast entirely with sand. Furthermore, the beam cast with 10 % rubber and strengthened with inclined plates fixed using both epoxy and steel anchors exhibited the highest increase in ultimate load and ductility among the tested specimens, with improvements of 32 % and 85 %, respectively, relative to the reference beam. In addition to the experimental program, this study develops an analytical model to predict the ultimate load of rubberized beams strengthened with SHCC plates, considering the rubber content, the arrangement of the strengthening plates, and the fixation method.</div></div>","PeriodicalId":9641,"journal":{"name":"Case Studies in Construction Materials","volume":"23 ","pages":"Article e04936"},"PeriodicalIF":6.5,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144313465","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":"Quantitative infrared detection methods for debonding in concrete-filled steel tubes during the hydration heat phase","authors":"Haonan Cai ,&nbsp;Chongsheng Cheng ,&nbsp;Hong Zhang ,&nbsp;Jianting Zhou","doi":"10.1016/j.cscm.2025.e04933","DOIUrl":"10.1016/j.cscm.2025.e04933","url":null,"abstract":"<div><div>Conducting rapid quantitative debonding detection after the completion of Concrete-filled steel tube (CFST) pouring is crucial for the timely identification and repair of potential structural issues. Currently, there is a lack of an infrared detection method that can perform quantitative detection specifically during the construction phase of CFST. This study proposes a Discreteness-Based Image Preprocessing (DBIP) method, combined with Otsu’s and K-means image segmentation methods, to explore its effectiveness in detecting debonding in CFST during the hydration heat phase. A full-scale CFST model was used to simulate debonding areas of different sizes, and infrared thermal imaging data were collected. The results show that the DBIP method significantly improved detection accuracy, and the DBIP+K-means combination can effectively quantify debonding areas with a minimum side length of 126 mm (10 % debonding rate). The study also reveals that the correlation between the F1-score and thermal contrast is linear when the thermal contrast is between 0°C and 0.18°C. When the thermal contrast exceeds 0.18°C, the F1-score stabilizes at approximately 0.8. The finding clarifies the detection accuracy range under different thermal contrast conditions and suggests potential optimization directions for the quantification of CFST debonding in practical application via infrared thermography.</div></div>","PeriodicalId":9641,"journal":{"name":"Case Studies in Construction Materials","volume":"23 ","pages":"Article e04933"},"PeriodicalIF":6.5,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144307077","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 interfacial bonding and pore structure optimization in 3D-printed high-strength ECC with steel-PE hybrid fibers","authors":"Yu Zhao ,&nbsp;Guanghai Shen ,&nbsp;Lingli Zhu ,&nbsp;Yahong Ding ,&nbsp;Xuemao Guan","doi":"10.1016/j.cscm.2025.e04934","DOIUrl":"10.1016/j.cscm.2025.e04934","url":null,"abstract":"<div><div>Engineered cementitious composites (ECC) are ideal candidates for 3D-printed concrete (3DPC) due to their excellent strain-hardening properties; however, the interlayer interfacial defects caused by the layer-by-layer stacking process severely restrict the development of their mechanical properties. In this study, we propose to adopt a steel fiber/polyethylene(PE) fiber hybrid reinforcement strategy to systematically investigate the mechanism of the influence of steel fiber compounding ratio (0–0.6 vol%) on the splitting strength and pore structure of the interlayer interfaces of 3D-printed high-strength ECC (HS-ECC). The three-dimensional distribution of pores was quantitatively resolved by X-ray computed tomography (X-CT), and the micro-morphology of the transition zone at the fiber-matrix interface was observed by scanning electron microscopy (SEM). The test shows that: when the steel fiber doping is increased to 0.6 %, the compressive strength is improved by about 15 %, and the interfacial splitting tensile strength is improved by 50.12 %, but the uniaxial tensile strain capacity decreases by 18.92 %, which reveals that there is a strength-ductility trade-off effect in the proportion of fiber mixing; the X-CT reconstruction reveals that the porosity within the strips of the printed specimen is reduced by 15.01 % compared with that of the poured molding and the porosity is dominated by small pores of a pore size of &lt; 100 μm, but the interlayer interfacial interface microforms. The X-CT and SEM analyses confirmed that the steel fibers showed a significant orientation distribution in the printing direction, which inhibited the interface crack extension through the bridging effect. By optimizing the fiber orientation distribution and the microstructure of the interlayer interface, the compound-mixed steel fibers significantly improved the interfacial splitting tensile strength, which provides an effective way to solve the problem of weak interlayer surfaces in 3DPC, and is of great significance in improving the quality of 3DPC.</div></div>","PeriodicalId":9641,"journal":{"name":"Case Studies in Construction Materials","volume":"23 ","pages":"Article e04934"},"PeriodicalIF":6.5,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144321626","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 moment improvement in UHPC strengthened damaged RC beams based on data augmented machine learning","authors":"Weidong Xu ,&nbsp;Decheng Ji ,&nbsp;Yong Yu ,&nbsp;Xianying Shi","doi":"10.1016/j.cscm.2025.e04939","DOIUrl":"10.1016/j.cscm.2025.e04939","url":null,"abstract":"<div><div>Strengthening of damaged reinforced concrete (RC) structures with ultra high performance concrete (UHPC) can increase their load carrying capacity and durability. However, there are limited studies that forecast the moment improvement (<em>M</em>_u) in strengthening damaged RC beams. The aim of this study is to develop a reliable model that can precisely predict <em>M</em>_u. Initially, the researchers gathered 173 datasets from experimental studies. Due to the limited amount of data available, kernel density estimation (KDE) was employed to expand the data. Subsequently, six machine learning algorithms were developed to predict the <em>M</em>_u. In addition, a new prediction model was constructed by considering the failure modes of the strengthened beams. Finally, Shapley Additive Explanations were employed to conduct an evaluation of model explainability. The results show that KDE can improve the robustness and accuracy of the model. Extreme gradient boosting performed best in predicting <em>M</em>_u and considering the failure mode could improve the accuracy of the model. The height of the RC beam, the reinforcement ratio of the UHPC, and the width of the RC beam have a large and proportional effect on <em>M</em>_u. This study can provide guidance for the engineering design of UHPC strengthened damaged RC beams.</div></div>","PeriodicalId":9641,"journal":{"name":"Case Studies in Construction Materials","volume":"23 ","pages":"Article e04939"},"PeriodicalIF":6.5,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144291612","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}