Case Studies in Construction Materials最新文献

{"title":"Experimental and analytical evaluation of mechanical properties of rubberized concrete incorporating waste tire crumb rubber","authors":"Xiaoyan Han ,&nbsp;Li Wang ,&nbsp;Aijiu Chen ,&nbsp;Lingyun Feng ,&nbsp;Yanting Ji ,&nbsp;Zhihao Wang ,&nbsp;Zhenzan Gao ,&nbsp;Keliang Li ,&nbsp;Qun Yuan ,&nbsp;Xiaozhou Xia ,&nbsp;Qing Zhang","doi":"10.1016/j.cscm.2025.e04970","DOIUrl":"10.1016/j.cscm.2025.e04970","url":null,"abstract":"<div><div>This research elucidates the mechanical behavior of rubberized concrete produced with waste tire crumb rubber as a substitute for fine aggregate, a crucial step given the lack of established standards for rubberized concrete design. We scrutinized the tensile strength (<em>f</em>_ts), flexural strength (<em>f</em>_f), and modulus of elasticity (<em>E</em>_c) of rubberized concrete with varying crumb rubber contents, sizes, and pretreatment methods. The mechanisms through which crumb rubber impacts concrete strength were explored, accounting for variances in particle sizes, rubber contents, and pretreatment methods. Over 400 groups of data from existing studies were analyzed to quantify the effect of rubber size, content, and pretreatment on the mechanical properties of rubberized concrete. Results revealed significant variations; notably, as rubber content increased from 0.0 % to 3.0 %, the <em>f</em>_ts in concrete with crumb rubbers sized 100 mesh, 1–2 mm, and 2–4 mm decreased by 32.2 %, 18.6 %, and 13.2 %, respectively. Conversely, increasing the rubber size from 100 mesh to 1–2 mm and 2–4 mm resulted in notable increases in <em>f</em>_ts, <em>f</em>_f, and <em>E</em>_c. The study further identified that the alterations in concrete's void structure due to crumb rubber inclusion significantly affect its mechanical properties. Our comprehensive analysis led to the development of evaluation equations for <em>f</em>_ts, <em>f</em>_f, and <em>E</em>_c of rubberized concrete, presenting a robust method to predict the mechanical properties of rubberized concrete with varied crumb rubber incorporations. This work bridges a significant gap in the analytical evaluation of rubberized concrete, paving the way for advancing its application in sustainable construction practices.</div></div>","PeriodicalId":9641,"journal":{"name":"Case Studies in Construction Materials","volume":"23 ","pages":"Article e04970"},"PeriodicalIF":6.5,"publicationDate":"2025-06-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144338760","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":"The water absorption and release performance and mechanism of superabsorbent polymers in the solution and paste","authors":"Jingjing Lyu ,&nbsp;Shuo Feng ,&nbsp;Jian Chen ,&nbsp;Deao Kong ,&nbsp;Runzhao Song","doi":"10.1016/j.cscm.2025.e04955","DOIUrl":"10.1016/j.cscm.2025.e04955","url":null,"abstract":"<div><div>Superabsorbent polymers (SAPs) are organic polymers capable of absorbing and retaining large amounts of water, with variations in their absorption and release properties impacting the mix design, microstructure, mechanical properties, and durability of cement-based materials. This study investigated the effects of SAP type (sodium polyacrylate, AA and polyacrylic acid-acrylamide copolymer, AM) and particle size on water absorption capacity, as well as the effects of environmental temperature and humidity on the release behaviour of saturated SAPs. The point-counting method was used to assess the actual absorption performance of SAPs in hardened paste, and SEM was used to observe the pore structure formed after water release. The results show that as the particle size of SAP increases, its water absorption capacity enhances, whereas its water release capacity decreases. AA absorbs water better than AM in deionized water, but the reverse is true in cement filtrate and hardened paste. AA is more sensitive to temperature, while AM shows greater sensitivity to humidity. The actual absorption performance of SAP in the paste can be obtained by using the method of assuming water absorption ratio. As the water-binder ratio increases, the absorption performance of SAP in the paste increases first and then decreases. SEM observations show that AA shrinks into a ball after the paste releases water, with a clear boundary with the surrounding matrix, while AM is tightly bonded to the paste after releasing water.</div></div>","PeriodicalId":9641,"journal":{"name":"Case Studies in Construction Materials","volume":"23 ","pages":"Article e04955"},"PeriodicalIF":6.5,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144335883","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":"Updated internal curing for HPC using pore-regulated coal aggregates","authors":"Changbai Wang ,&nbsp;Qinghua Liu ,&nbsp;Jimin Liu ,&nbsp;Lei Wang ,&nbsp;Peiyuan Chen","doi":"10.1016/j.cscm.2025.e04951","DOIUrl":"10.1016/j.cscm.2025.e04951","url":null,"abstract":"<div><div>An updated internal curing (IC) method was proposed using pore-regulated coal gangue aggregates (PCAs) for high-performance concrete (HPC). Calcination (200—400 °C) was applied to regulate the pore structure of PCAs to achieve an optimal one. The pore structure, morphology, water absorption, and water desorption of PCAs were tested. Their effects on the fluidity, internal relative humidity (IRH), autogenous shrinkage, compressive strength, micromechanical properties, and microstructure of HPC were studied. The results demonstrated that calcination significantly increased the porosity of PCAs by 19.57—34.95 %, particularly within the mesopores ranging from 30 nm to 1 μm, which led to a 29.38—81.12 % increase in the water absorption capacity of PCAs, as well as the improvement of water desorption efficiency. The incorporation of PCAs sustained the IRH of HPCs at elevated levels and reduced the autogenous shrinkage by 44—55 %. The improved IC efficiency facilitated the deposition of more hydration products and enhanced the interfacial transition zone (ITZ), contributing to refined pore structure and a 1—7.92 % increase in compressive strength at 28d.</div></div>","PeriodicalId":9641,"journal":{"name":"Case Studies in Construction Materials","volume":"23 ","pages":"Article e04951"},"PeriodicalIF":6.5,"publicationDate":"2025-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144329930","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":"Torsional capacity of prestressed assembled quarter-shell concrete tower with adhesive bonded vertical joints","authors":"Wei-Feng Tao ,&nbsp;Dorjee TseDan ,&nbsp;Dong-Liang Zhang ,&nbsp;Ci-Rong Huang ,&nbsp;Kun Fu ,&nbsp;Chu Zhao ,&nbsp;Jia-Wei Zhang ,&nbsp;Jun-Lin Li ,&nbsp;Zhi-Qiang Wan","doi":"10.1016/j.cscm.2025.e04947","DOIUrl":"10.1016/j.cscm.2025.e04947","url":null,"abstract":"<div><div>Prestressed assembled concrete tower with adhesive bonded vertical joints is currently a prevailing type of supporting structure of large-scaled onshore wind turbines. However, few works have been done to study the effect of the adhesive bonding on the mechanical behavior of this type of concrete towers. In this paper, the failure mechanism and torsional capacity of a quarter-shell concrete tower with adhesive bonded vertical joints were studied through finite element analysis. The failure sequences of the vertical joints in two typical load cases along with their influence on the stress distributions on the horizontal joints were discussed in detail. In addition, the torsional capacities evaluated by the free torsion model and constrained torsion model were compared with the simulation results, and the differences among them were explained. It was found that in the nonlinear stage of torsion, the compressive stress distributions on the horizontal joints no longer comply with the plain section assumption, and it is inappropriate to regard the concrete segments as thin-walled members. The constrained torsion model can be employed to evaluate the torsional capacity of whole ring towers quite well, but does not apply to quarter-shell towers. The torsional capacity of the quarter-shell tower is determined by the strengths of the vertical joints in several segments below the position of variable cross-section, rather than by the strengths of the horizontal joints. The results presented in this paper are expected to facilitate more rational design of concrete towers in the wind power industry.</div></div>","PeriodicalId":9641,"journal":{"name":"Case Studies in Construction Materials","volume":"23 ","pages":"Article e04947"},"PeriodicalIF":6.5,"publicationDate":"2025-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144471926","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":"TRM versus FRP: Can cement-based matrices replace organic binders in the flexural strengthening of reinforced low-grade concrete beams?","authors":"Pello Larrinaga ,&nbsp;Jesus-Maria Romera ,&nbsp;David Garcia-Estevez ,&nbsp;Jose-Tomas San-Jose","doi":"10.1016/j.cscm.2025.e04948","DOIUrl":"10.1016/j.cscm.2025.e04948","url":null,"abstract":"<div><div>The rehabilitation of aging housing estates has become increasingly critical due to the deterioration of concrete structures from environmental exposure, design deficiencies, and poor maintenance. Fibre Reinforced Polymers (FRPs) have been extensively studied and applied for structural strengthening but exhibit limitations such as substrate incompatibility, poor performance under extreme temperatures, and moisture sensitivity—issues particularly pronounced in low-grade concrete and masonry. As an alternative, Textile Reinforced Mortar (TRM), which replaces the organic matrix in FRPs with cement-based mortar, has emerged as a promising solution. The objective of this work is to compare the structural performance of both matrices when applied in flexural strengthening of beams with the same amount of composite reinforcement (steel or carbon textiles). For that aim, twelve one-third scale beams (1.5 m span) fabricated with low quality concrete were tested under four-point bending. For the case of TRM-retrofitted beams, a custom-designed cementitious mortar was designed, characterized and used as composite matrix. The results indicate that TRM composites significantly improve load-bearing capacity and ductility, especially when steel textiles are employed, making it a feasible alternative to traditional FRP systems. The findings underscore TRM’s potential as a durable, compatible, and cost-effective strengthening method, advancing its applicability in the rehabilitation of deteriorated concrete infrastructure. These results contribute to the growing body of knowledge on the application of TRM in structural rehabilitation and offer valuable insights for future research and practical applications in the field of construction.</div></div>","PeriodicalId":9641,"journal":{"name":"Case Studies in Construction Materials","volume":"23 ","pages":"Article e04948"},"PeriodicalIF":6.5,"publicationDate":"2025-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144321627","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":"Predictive modeling and degradation mechanisms of rubber sealing materials under stress-thermal oxidative aging for long-term sealing performance","authors":"Long Chen ,&nbsp;Jie Ren ,&nbsp;Yuan Wang","doi":"10.1016/j.cscm.2025.e04949","DOIUrl":"10.1016/j.cscm.2025.e04949","url":null,"abstract":"<div><div>Rubber sealing materials are extensively utilized in engineering applications due to their superior sealing performance; however, their long-term durability poses a significant challenge. To address this issue, this study examines the aging behaviors of rubber materials, including stress relaxation and compression set, and incorporates these behaviors into a predictive model for impermeability performance. The rubber strain was analytically decomposed into elastic strain and viscoelastic strain, the latter representing permanent compression deformation. Based on this decomposition, a time-temperature conversion model was developed. Compression stress-thermal oxidative aging tests were conducted to validate the model, producing time and temperature-dependent expressions for permanent compression deformation and constitutive parameters of the rubber material. Additionally, degradation mechanisms were investigated using Fourier Transform Infrared Spectroscopy (FTIR) and Scanning Electron Microscopy (SEM), revealing significant molecular-level oxidation, polymer chain scission, crosslink degradation, and the emergence of microstructural defects such as cracks and interfacial debonding. The validated model was then employed in numerical simulations, implemented through a UMAT secondary development program, to investigate the degradation trends of impermeability performance under varying time and temperature conditions. The results elucidate the degradation mechanisms and trends of impermeability performance, offering critical insights into the long-term behavior of rubber sealing materials. These findings provide theoretical guidance for optimizing the design and performance evaluation of rubber gaskets in practical engineering applications, thereby enhancing their durability and reliability in demanding operational environments.</div></div>","PeriodicalId":9641,"journal":{"name":"Case Studies in Construction Materials","volume":"23 ","pages":"Article e04949"},"PeriodicalIF":6.5,"publicationDate":"2025-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144335823","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 flexural behavior of CO2 cured recycled coarse aggregate concrete steel bar trusses composite slab","authors":"Yueqing Gao ,&nbsp;Sijie Shen ,&nbsp;Ke Ye ,&nbsp;Zeshen Li ,&nbsp;Wei Wang ,&nbsp;Jingyi Lu ,&nbsp;Shaodan Hou ,&nbsp;Yangyang Yin ,&nbsp;Chaofeng Liang","doi":"10.1016/j.cscm.2025.e04940","DOIUrl":"10.1016/j.cscm.2025.e04940","url":null,"abstract":"<div><div>The effects of aggregate carbonation, overall specimen carbonation, and the combined method of aggregate carbonation and overall specimen carbonation on the mechanical properties of recycled coarse aggregate concrete (RAC) were investigated. Furthermore, the flexural behaviors of steel bar trusses composite slab (SBTCS) prepared by RAC and cured by the three carbonation methods were studied through experiments and numerical analysis. The results indicated that: (1) The mechanical properties of RAC after carbonation were significantly improved, and the concrete prepared by the combined method of aggregate carbonation and overall specimen carbonation showed the highest strength. (2) The stress-strain constitutive models of RAC under different carbonation methods were built according to the experimental results. (3) The failure modes of the carbonated concrete SBTCSs were basically consistent and the precast layer and the cast-in-situ layer deformed coordinately during the loading process. (4) The SBTCS prepared by the combined method of aggregate carbonation and overall specimen carbonation showed the best bending performance, and the ultimate load bearing capacity increased by 16.2 % compared to the SBTCS made by non-carbonated RAC. (5) The load-displacement curves and damage contours of the SBTCSs obtained from the numerical analysis were in good agreement with the experimental results, and the maximum deviation between the simulated ultimate load and the experimental value was 8.8 %.</div></div>","PeriodicalId":9641,"journal":{"name":"Case Studies in Construction Materials","volume":"23 ","pages":"Article e04940"},"PeriodicalIF":6.5,"publicationDate":"2025-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144335824","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":"Synthesis and characteristic of decomposed products from recycled concrete fines by acetic acid decomposition treatment","authors":"Chen Chen ,&nbsp;Liguo Wang ,&nbsp;Shiyu Sui ,&nbsp;Fengjuan Wang ,&nbsp;Qi Zheng ,&nbsp;Jinyang Jiang","doi":"10.1016/j.cscm.2025.e04950","DOIUrl":"10.1016/j.cscm.2025.e04950","url":null,"abstract":"<div><div>In this work, an acetic acid decomposition method was proposed to synthesize amorphous nano-silica and calcium acetate rich solution from the recycled concrete fines (RCF), waste concrete with the aggregates removed, which realized the conversion of RCF into high value-added products by separating and purifying the phases of calcium and silicon. Characterization was carried out by means of thermogravimetry, Fourier transformation-infrared spectroscopy, electron microscope, ²⁹Si Solid-state nuclear magnetic resonance and BET method to better investigate the phases assemblage evolution and their microstructure development during decomposition systematically. The results indicated that the RCF was decomposed rapidly to generate amorphous silica bearing gel. A purified amorphous nano-silica gel was successfully prepared with high porosity, high polymerization degree and high purity up to 99.3 %. And a calcium acetate rich solution was obtained as well. Both decomposed products have proved to be beneficial to the cementitious material system. The work provides technical and theoretical support for the complete and efficient reuse of the recycled cementitious material system during the later stages.</div></div>","PeriodicalId":9641,"journal":{"name":"Case Studies in Construction Materials","volume":"23 ","pages":"Article e04950"},"PeriodicalIF":6.5,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144329929","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":"The influence mechanism of wet-ground ultra-fine granulated blast furnace slag on the shrinkage cracking sensitivity of cementitious materials based on the eccentric ring test","authors":"Cong Tian ,&nbsp;Nan Chen ,&nbsp;Xingyang He ,&nbsp;Can Mei ,&nbsp;Ying Su ,&nbsp;Liang Xiong ,&nbsp;Xingyuan Ma ,&nbsp;Zhengqi Zheng","doi":"10.1016/j.cscm.2025.e04942","DOIUrl":"10.1016/j.cscm.2025.e04942","url":null,"abstract":"<div><div>Improving the hydration activity of supplementary cementitious materials (SCMs) through ultra-refinement to enhance their application in concrete is a critical development direction for achieving both low carbon emissions and high performance. However, ultrafine SCMs may reduce workability and increase risk of early shrinkage cracking of cementitious materials. In this research, ordinary and wet-ground ultra-fine granulated blast furnace slag (WGGBS) were selected as the subjects of study. The shrinkage and cracking performance of the two types of ultra-fine GGBS cementitious materials were characterized by the eccentric ring test. The cracking risk at various positions of the eccentric ring specimen was analyzed through theoretical analysis in the bipolar coordinate system. The effect of ultra-fine GGBS dosage on the hydration and pore structure of the cementitious materials was clarified. The results indicate that both types of ultrafine GGBS can accelerate the hydration of cement and promote the rapid refinement of pore structure, leading to an increase in the autogenous shrinkage of cementitious materials. Conversely, WGGBS cementitious materials exhibit lower porosity, improved water retention, and greater compressive strength at 7 days. WGGBS significantly reduces drying shrinkage and extends both the initial cracking and through-cracking times. The autogenous and drying shrinkage of cementitious materials are less sensitive to the content of WGGBS compared to OGGBS. WGGBS demonstrates more pronounced advantages in enhancing mechanical strength and crack resistance. This study provides theoretical support for the coordinated optimization of mechanical strength and resistance to shrinkage cracking in cementitious materials prepared with ultra-fine GGBS.</div></div>","PeriodicalId":9641,"journal":{"name":"Case Studies in Construction Materials","volume":"23 ","pages":"Article e04942"},"PeriodicalIF":6.5,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144338838","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":"Electrical conduction model and equivalent circuit of cementitious composites containing nano additives","authors":"Yunyang Wang ,&nbsp;Sha Liu ,&nbsp;Liqing Zhang ,&nbsp;Shengwei Sun ,&nbsp;Chenggong Zhao ,&nbsp;Yonghui Qin","doi":"10.1016/j.cscm.2025.e04952","DOIUrl":"10.1016/j.cscm.2025.e04952","url":null,"abstract":"<div><div>Electrical conductivity cementitious composites have advantages of superior electrical conductivity, favorable mechanical property, possessing multifunctionality, thus, exhibiting widely prospect in intelligent civil infrastructures. In this paper, the cementitious composites containing the hybrid carbon nano tubes (CNTs) and nano carbon blacks (NCBs) are prepared firstly. And then, the CNTs and NCBs with dosages variation from 0.0 to 5.0 vol% effect on electrical conduction of the composites are systematically investigated. Finally, the electrical conduction model combination with equivalent circuit is proposed to explore the electrical conduction mechanisms in-depth. Results show that the electrical resistivity of the composites is reduced up to three orders of magnitude with increasing concentration of the CNTs and NCBs, and the relationship between electrical conductivity and content of the CNTs and NCBs follows the percolation theory. The electrical conduction features can be precisely explained using the proposed electrical conduction model accompanies with equivalent circuit. The originality of the present study is proposed the electrical conduction model and equivalent circuit of the cementitious composites containing the hybrid CNTs and NCBs. Therefore, the findings of the present research will pave an extensive path for utilization of electrical conductivity cementitious composites in developing multifunctional civil infrastructures.</div></div>","PeriodicalId":9641,"journal":{"name":"Case Studies in Construction Materials","volume":"23 ","pages":"Article e04952"},"PeriodicalIF":6.5,"publicationDate":"2025-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144364390","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}