Cement and Concrete Composites最新文献

Manuscript to be submitted to Cement and Concrete Composites Bentonite-based LC3 low carbon cement and activation by C-S-H nucleation seeding

Cement and Concrete Composites Pub Date : 2025-03-31 DOI: 10.1016/j.cemconcomp.2025.106073

Diego Vallina, María Dolores Rodríguez-Ruiz, Alejandro Morales-Cantero, Ana Cuesta, Isabel Santacruz, Alessandro Dalla-Libera, Pere Borralleras, Sébastien Dhers, Peter Schwesig, Oliver Mazanec, Miguel A.G. Aranda, Angeles G. De la Torre

{"title":"Manuscript to be submitted to Cement and Concrete Composites Bentonite-based LC3 low carbon cement and activation by C-S-H nucleation seeding","authors":"Diego Vallina, María Dolores Rodríguez-Ruiz, Alejandro Morales-Cantero, Ana Cuesta, Isabel Santacruz, Alessandro Dalla-Libera, Pere Borralleras, Sébastien Dhers, Peter Schwesig, Oliver Mazanec, Miguel A.G. Aranda, Angeles G. De la Torre","doi":"10.1016/j.cemconcomp.2025.106073","DOIUrl":"https://doi.org/10.1016/j.cemconcomp.2025.106073","url":null,"abstract":"This study explores the feasibility of using calcined bentonitic clays in LC3-50 binders. Four commercially available bentonite rocks were thermally activated and milled to a Dv,50 of 12±2 μm. Their pozzolanic activities were assessed using the R3 method, yielding total heat released values between 190 and 378 J/g-SCM, exceeding the minimum requirements for supplementary cementitious materials (SCMs). The incorporation of superplasticisers (SP) in bentonitic LC3 mortars was optimized, requiring dosages between 0.7 and 1.1 wt% (by the weight of binder) to achieve an initial slump of 200±20 mm, with flow maintained for one hour in three of them. These results dispel concerns regarding the use of SP in LC3 containing calcined bentonites.Early-age hydration reactions were accelerated using C-S-H nucleation seeding technology, which increased bentonite LC3 mortar compressive strength by 50% at one day. The compressive mechanical strengths at 28 days of the seeded mortars were also enhanced by 15%.To elucidate the effects of C-S-H nucleation seeding, LC3 pastes were analysed, confirming the occurrence of pozzolanic reactions at one day of hydration. The portlandite contents, determined by Rietveld quantitative phase analysis and thermal analysis, were lower than expected based on the alite hydration degree at the analysed times. Furthermore, the strength enhancing admixture systematically increased the formation of AFm-type phases, such as hemicarboaluminate, and refined the pore microstructure at one day of hydration.","PeriodicalId":519419,"journal":{"name":"Cement and Concrete Composites","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143737250","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Nano-structure and sensitivity of self-sensing geopolymer composites containing nano carbon black

Cement and Concrete Composites Pub Date : 2025-03-28 DOI: 10.1016/j.cemconcomp.2025.106072

Dongyu Wang, Zuhua Zhang, Siqi Ding, Chaolie Ning, Cheng Shi, Yuwei Ma, Qiang Ren, Zhengwu Jiang

{"title":"Nano-structure and sensitivity of self-sensing geopolymer composites containing nano carbon black","authors":"Dongyu Wang, Zuhua Zhang, Siqi Ding, Chaolie Ning, Cheng Shi, Yuwei Ma, Qiang Ren, Zhengwu Jiang","doi":"10.1016/j.cemconcomp.2025.106072","DOIUrl":"https://doi.org/10.1016/j.cemconcomp.2025.106072","url":null,"abstract":"Geopolymer has unique microstructure, high concentration of alkali cations and low carbon footprint features, which is a promising substitute to ordinary Portland cement (OPC) to produce self-sensing cementitious composites. However, the effects of replacing OPC with a geopolymer matrix and incorporating conductive fillers on the self-sensing behavior and consequent mechanisms of self-sensing geopolymer composites (SSGCs) remain unclear. This study investigates the modification effects of nano carbon black (NCB, 0-6.0 wt%) on the mechanical, electrical, and self-sensing properties of SSGCs. To comprehensively elucidate the sensing mechanism, the roles of NCB and multiphases of SSGC matrix, were analyzed through microstructural and chemical characterizations from the geopolymerization process to self-sensing behavior under compression. Experimental results showed that SSGCs containing NCB demonstrated excellent electrical and sensing properties, particularly in detecting initial crack formation and the ultimate failure. The sensing mechanism was primarily governed by the migration of free ions in pore solutions, the establishment of charge balance and the formation of local dipoles under compressive load. SSGCs having low concentration of NCB exhibited poor sensitivity. With NCB content increasing, the rearrangement of NCB particles and the reconstruction of the conductive network contribute to the enhanced sensing properties. SSGCs integrated structural and self-sensing advantages are promising to advance structural health monitoring throughout the life cycle.","PeriodicalId":519419,"journal":{"name":"Cement and Concrete Composites","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143734198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Active control of the SAP desorption in concrete through acoustic emission for optimized curing

Cement and Concrete Composites Pub Date : 2025-03-26 DOI: 10.1016/j.cemconcomp.2025.106067

Eleni Korda, Annelise Cousture, Eleni Tsangouri, Didier Snoeck, Geert De Schutter, Dimitrios G. Aggelis

{"title":"Active control of the SAP desorption in concrete through acoustic emission for optimized curing","authors":"Eleni Korda, Annelise Cousture, Eleni Tsangouri, Didier Snoeck, Geert De Schutter, Dimitrios G. Aggelis","doi":"10.1016/j.cemconcomp.2025.106067","DOIUrl":"https://doi.org/10.1016/j.cemconcomp.2025.106067","url":null,"abstract":"The quality and durability of concrete strongly depend on the mixing and curing processes. Relative humidity and temperature changes can induce premature drying, resulting in shrinkage cracking. Monitoring and controlling the concrete curing process is essential in preventing undesirable behaviours. Methods such as acoustic emission (AE) have proven promising for monitoring the curing of cementitious materials due to their high sensitivity and simple application. Shrinkage cracking can be mitigated using admixtures such as superabsorbent polymers (SAPs) which provide internal curing to the concrete matrix for several hours after casting. Their action taking place in the microstructure, although beneficial, is difficult to trace or control. However, recently it was shown that the release of SAP water (desorption) into the cementitious matrix is accompanied by high AE recordings enabling monitoring of the process. This study presents a novel methodology using real-time AE data to actively control internal curing, optimizing curing conditions and material properties. By treating the concrete surface with water, at the moments dictated by the increased AE signals, the desorption of SAP water is delayed, allowing multiple activation cycles, extending internal curing, and enhancing hydration. Results indicate improved mechanical properties, with increased compressive strength and ultrasonic pulse velocity for the actively controlled SAP concrete compared to conventional SAP concrete. Finally, scanning electron microscopy (SEM) measurements near the surface, showed a 70% and 81% reduction of cracking compared to untreated SAP concrete and conventional concrete, respectively, demonstrating the importance of active curing on the shrinkage-prone near-the-surface area.","PeriodicalId":519419,"journal":{"name":"Cement and Concrete Composites","volume":"61 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143713411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Experimental and Mechanical-based Analysis of Fatigue-Induced Pull-Out Degradation in Single Hooked-End Steel Fiber in Fiber-Reinforced Cementitious Composites

Cement and Concrete Composites Pub Date : 2025-03-18 DOI: 10.1016/j.cemconcomp.2025.106054

Mohamed Adel, Wang Li, Yan Xiao, Tamon Ueda

{"title":"Experimental and Mechanical-based Analysis of Fatigue-Induced Pull-Out Degradation in Single Hooked-End Steel Fiber in Fiber-Reinforced Cementitious Composites","authors":"Mohamed Adel, Wang Li, Yan Xiao, Tamon Ueda","doi":"10.1016/j.cemconcomp.2025.106054","DOIUrl":"https://doi.org/10.1016/j.cemconcomp.2025.106054","url":null,"abstract":"Fatigue analysis of steel fiber-reinforced cementitious composites (SFRCC) is crucial for structural design and safety assessment under repeated loading cycles. Experimental studies have demonstrated cyclic degradation in SFRCC, attributed to the deterioration of fiber-bridging strength. However, a comprehensive analytical quantification of fatigue-dependent parameters for deformed fibers across multiple scales remains limited. This study aims to characterize the fatigue dependency of SFRCC at the fiber-scale through analytical models based on experimental investigations. Static and fatigue pull-out tests were conducted on single hooked-end steel fibers embedded with a 20 mm length. Fibers were initially pulled to varying displacement levels (0.125, 0.25, 0.50, 0.75, 1.00, 2.50, 4.00, and 5.00 mm) before cyclic loading. Fatigue tests at a frequency of 5 Hz continued up to two million loading cycles or until pull-out failure, during which the fiber hook was progressively straightened. X-ray Computed Tomography (CT) scans were employed to investigate the associated failure mechanisms. A novel mechanical model was proposed to capture the displacement evolution rate during fatigue pull-out loading and predict the fatigue life. This model demonstrates a satisfactory correlation with the experimental results, providing a valuable tool for understanding and predicting the fatigue behavior of SFRCC.","PeriodicalId":519419,"journal":{"name":"Cement and Concrete Composites","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143653549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Influence of MgAl–NO2-LDHs on passivation of reinforcing steel in simulated geopolymer solution MgAl-NO2-LDHs 对模拟土工聚合物溶液中钢筋钝化的影响

Cement and Concrete Composites Pub Date : 2024-07-25 DOI: 10.1016/j.cemconcomp.2024.105676

Yuchen Wu, Zhipeng Xu, Jiangwei Zhu, Fengjiang Li, Jie Hu, Yuwei Ma, Zuhua Zhang, Haoliang Huang, Jiangxiong Wei, Qijun Yu, Caijun Shi

引用次数: 0