Cement & concrete composites最新文献_第6页

Reactions between BOF slag and acidic phosphate: shifting acid-base reaction towards hydration 转炉炉渣与酸性磷酸盐之间的反应：将酸碱反应转向水化

IF 13.1 1区工程技术

Cement & concrete composites Pub Date : 2025-08-18 DOI: 10.1016/j.cemconcomp.2025.106298

Yanjie Tang , Katrin Schollbach , Sieger van der Laan , Wei Chen

{"title":"Reactions between BOF slag and acidic phosphate: shifting acid-base reaction towards hydration","authors":"Yanjie Tang , Katrin Schollbach , Sieger van der Laan , Wei Chen","doi":"10.1016/j.cemconcomp.2025.106298","DOIUrl":"10.1016/j.cemconcomp.2025.106298","url":null,"abstract":"<div><div>The growing demand for sustainable cement alternatives, coupled with the underutilization of Basic Oxygen Furnace (BOF) slag in high-value applications, underscores the need for innovative binder solutions to reduce CO<sub>2</sub> emissions and waste. This study addresses the challenge of limited hydration in BOF slag, which restricts its use as a cement-free binder in conventional alkaline activation. A novel approach using monopotassium phosphate (MKP) at dosages below 10 wt% is proposed to activate the latent hydraulic phases of BOF slag, specifically dicalcium silicate (C<sub>2</sub>S) and brownmillerite (C<sub>2</sub>(A,F)), at ambient temperature. The microstructure and strength development of BOF slag pastes were examined using a multi-technique approach, including quantitative XRD, SEM/EDX with phase mapping, TGA, calorimetric measurements, MIP, etc. The dosage of MKP is pivotal in modulating the transition from acid-base reactions to sustained hydration in BOF slag-based binders. Findings demonstrate that MKP enhances C<sub>2</sub>S and C<sub>2</sub>(A,F) hydration, producing hydrotalcite, pyroaurite, C-S-H gel, hydrogarnet, and hydroxyapatite-like phases. An optimal MKP dosage of 5 wt% achieves maximum strength at both 7 and 28 days (19.9 and 44.5 MPa), while 2.5 wt% MKP affects slightly 7-day hydration but promotes 28-day hydration. Conversely, excessive MKP (10 wt%) triggers rapid early reactions, forming large pores that impair strength. These results underscore the critical need for balanced phosphate dosages to optimize hydration and mechanical performance, offering a viable strategy for valorizing BOF slag in sustainable construction.</div></div>","PeriodicalId":9865,"journal":{"name":"Cement & concrete composites","volume":"164 ","pages":"Article 106298"},"PeriodicalIF":13.1,"publicationDate":"2025-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144867111","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

On the relevance of pyrite oxidation: A thermodynamic and experimental evaluation of concrete degradation 黄铁矿氧化的相关性：混凝土降解的热力学和实验评价

IF 13.1 1区工程技术

Cement & concrete composites Pub Date : 2025-08-17 DOI: 10.1016/j.cemconcomp.2025.106295

A.C. Valdés , D.J. De Souza , A.P.B. Capraro , R. Pieralisi , M.H.F. Medeiros

{"title":"On the relevance of pyrite oxidation: A thermodynamic and experimental evaluation of concrete degradation","authors":"A.C. Valdés , D.J. De Souza , A.P.B. Capraro , R. Pieralisi , M.H.F. Medeiros","doi":"10.1016/j.cemconcomp.2025.106295","DOIUrl":"10.1016/j.cemconcomp.2025.106295","url":null,"abstract":"<div><div>The oxidation of pyrite in cement-based materials induces complex chemical and mechanical degradation. This study combines thermodynamic modelling with experimental analysis to understand the mechanisms behind this deterioration. The results show that pyrite oxidation leads to iron hydroxide precipitation, generating localised crystallisation pressures that promote intra-granular fracturing. The release of sulphate raises the formation of ettringite and gypsum, further increasing expansive stress. The inclusion of air-entraining admixtures alters this degradation process by redistributing internal stresses, thus mitigating crack propagation. Thermodynamic simulations predict phase stability and precipitation kinetics, highlighting the role of local supersaturation in driving microstructural disruption. The primary contribution of this study is the development of a model for the progression of internal sulphate reaction. The model suggests that the initial damage phase is driven by secondary ettringite formation, resulting in a buildup of crystallisation pressure. As oxidation progresses, iron hydroxide precipitation dominates, exacerbating expansion and accelerating degradation.</div></div>","PeriodicalId":9865,"journal":{"name":"Cement & concrete composites","volume":"164 ","pages":"Article 106295"},"PeriodicalIF":13.1,"publicationDate":"2025-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144867110","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Synthesizing amorphous single-phase of fly ash to understand its alkali activation effect 合成非晶单相粉煤灰，了解其碱活化效果

IF 13.1 1区工程技术

Cement & concrete composites Pub Date : 2025-08-17 DOI: 10.1016/j.cemconcomp.2025.106293

Guanqi Wei, Biqin Dong, Rongxin Peng, Hui Zhong, Yanshuai Wang

{"title":"Synthesizing amorphous single-phase of fly ash to understand its alkali activation effect","authors":"Guanqi Wei, Biqin Dong, Rongxin Peng, Hui Zhong, Yanshuai Wang","doi":"10.1016/j.cemconcomp.2025.106293","DOIUrl":"10.1016/j.cemconcomp.2025.106293","url":null,"abstract":"<div><div>The heterogeneity of amorphous aluminosilicate phases leads to different chemical features among various fly ashes (FAs) in alkali-activated cement systems. Insufficient understanding of this heterogeneity and its underlying mechanisms limits the extensive utilization of FA. In this work, amorphous aluminosilicates in FAs were categorized into eight types via backscattered electron (BSE) imaging and energy dispersive spectroscopy (EDS) clustering techniques. An improved sol-gel method was innovatively introduced to synthesize single-phases with atomic stoichiometry and structure analogous to those of the categorized phases for systematic reactivity quantification. Phase-II and silicate, featuring high calcium content and elevated Si/Al molar ratios, exhibited optimal multi-scale activation effect, with their cumulative heat releases, 28-day reaction degrees, microhardness, and compressive strengths being 0.87–2.39, 2.43–4.78, 1.23–1.88, and 1.09–4.54 times higher than those of other phases, respectively. Alkali activation behavior demonstrated significant dependence on categorized phases. The proposed clustering method was validated, laying a foundation for phase-driven predictive modeling of FA-based alkali-activated materials. Coupling BSE-EDS clustering with sol-gel synthesis enables phase-separated investigation of amorphous aluminosilicates in solid wastes. This advancement provides critical scientific insights for elucidating reaction mechanisms and promoting high-value-added utilization of solid wastes.</div></div>","PeriodicalId":9865,"journal":{"name":"Cement & concrete composites","volume":"164 ","pages":"Article 106293"},"PeriodicalIF":13.1,"publicationDate":"2025-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144867115","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Self-sealing and -healing performance and environmental adaptability of concrete cracks using superabsorbent polymers 高吸水聚合物对混凝土裂缝的自密封、自愈合性能及环境适应性研究

IF 13.1 1区工程技术

Cement & concrete composites Pub Date : 2025-08-17 DOI: 10.1016/j.cemconcomp.2025.106292

Desheng Li , Jingtao Zhu , Qinjian Wang , Linlin Gu , Didier Snoeck

{"title":"Self-sealing and -healing performance and environmental adaptability of concrete cracks using superabsorbent polymers","authors":"Desheng Li , Jingtao Zhu , Qinjian Wang , Linlin Gu , Didier Snoeck","doi":"10.1016/j.cemconcomp.2025.106292","DOIUrl":"10.1016/j.cemconcomp.2025.106292","url":null,"abstract":"<div><div>Concrete structures often suffer from cracking under environmental stress, compromising durability and service life. Superabsorbent polymers (SAPs) have emerged as promising additives for autonomous crack sealing, yet their long-term performance under cyclic exposure remains unclear. This study investigates the self-sealing performance and durability of concrete modified with two SAP types (SAP1 and SAP2) subjected to freeze-thaw and dry-wet cycles. Crack width, permeability, and mass loss were monitored to assess sealing performance. SAP1 showed better early-stage sealing due to its high swelling capacity and gel formation but suffered from increased permeability and material loss after cycling. In contrast, SAP2 exhibited lower initial sealing but better long-term stability. SEM-EDS analysis revealed that SAP1 formed hydration-rich, amorphous gels, whereas SAP2 developed compact, carbonate-rich layers. These differences may be interpreted thermodynamically: SAP1 likely forms metastable gels prone to disruption, while SAP2 favors stable crystalline phases with stronger interfacial retention. A novel “Mass Sealing Efficiency” (<em>E</em><sub><em>m</em></sub>) metric was proposed to integrate permeability and material loss into a unified performance indicator. These findings reveal critical trade-offs between sealing intensity and environmental resilience, offering practical insights for the tailored design of SAP-based self-healing systems in concrete infrastructure.</div></div>","PeriodicalId":9865,"journal":{"name":"Cement & concrete composites","volume":"164 ","pages":"Article 106292"},"PeriodicalIF":13.1,"publicationDate":"2025-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144867113","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Multiscale investigation of sustainable spalling-resistant ultra-high performance concrete containing sludge-derived slag derivatives and recycled polypropylene fibre 含污泥衍生渣衍生物和再生聚丙烯纤维的可持续抗剥落超高性能混凝土的多尺度研究

IF 13.1 1区工程技术

Cement & concrete composites Pub Date : 2025-08-15 DOI: 10.1016/j.cemconcomp.2025.106289

Kevin Jia Le Lee , Zhenyu Zhang , Kang Hai Tan

{"title":"Multiscale investigation of sustainable spalling-resistant ultra-high performance concrete containing sludge-derived slag derivatives and recycled polypropylene fibre","authors":"Kevin Jia Le Lee , Zhenyu Zhang , Kang Hai Tan","doi":"10.1016/j.cemconcomp.2025.106289","DOIUrl":"10.1016/j.cemconcomp.2025.106289","url":null,"abstract":"<div><div>This study investigates the fire performance and microstructural evolution of ultra-high performance concrete (UHPC) incorporating ground sludge-derived slag (GSDS) as a partial cement replacement, sludge-derived slag (SDS) as a fine aggregate replacement (less than 4 mm) and recycled polypropylene (PP) fibres for spalling prevention. A multiscale approach was adopted to investigate the effect of GSDS addition on phase assemblages and degradation mechanisms of ordinary Portland cement (OPC) and OPC/GSDS systems at elevated temperatures, correlating microscopic observations with macroscopic spalling behaviour. The findings revealed that the accelerated hydration in OPC/GSDS samples promoted incorporation of aluminates (Al) into C-S-H and increased its degree of polymerisation, thereby enhancing resistance to high temperature-induced dehydration and improving strength retention up to 600 °C. Mercury intrusion porosimetry (MIP) further confirmed that GSDS contributed to a denser microstructure at elevated temperatures. Spalling tests showed that larger SDS aggregates induced interfacial microcracks, while PP fibres formed interconnected vapour-release pathways through tangential microcracks around the aggregates and empty fibre channels, collectively increasing permeability. With 12 kg/m<sup>3</sup> of recycled PP fibre, explosive spalling was completely prevented, reducing mass loss to 12.2 % compared to 100 % in the control UHPC. These results highlight the effectiveness of combining GSDS, SDS and PP fibres to develop a sustainable, spalling-resistant UHPC. This study provides valuable insights into the use of waste-derived supplementary cementitious materials (SCMs), alternative aggregates and fibres in enhancing the fire performance of UHPC, contributing to sustainable development in the built environment.</div></div>","PeriodicalId":9865,"journal":{"name":"Cement & concrete composites","volume":"164 ","pages":"Article 106289"},"PeriodicalIF":13.1,"publicationDate":"2025-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144851733","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Deciphering freeze–thaw induced degradation mechanisms in magnesium phosphate cement paste: Insights from three-dimensional quantitative characterization 解读冻融诱导的磷酸镁水泥浆降解机制：从三维定量表征的见解

IF 13.1 1区工程技术

Cement & concrete composites Pub Date : 2025-08-13 DOI: 10.1016/j.cemconcomp.2025.106283

Qinyuan Liang , Zihan Zhou , Qiang Wang , Haisen Jin , Shiyu Zhuang

{"title":"Deciphering freeze–thaw induced degradation mechanisms in magnesium phosphate cement paste: Insights from three-dimensional quantitative characterization","authors":"Qinyuan Liang , Zihan Zhou , Qiang Wang , Haisen Jin , Shiyu Zhuang","doi":"10.1016/j.cemconcomp.2025.106283","DOIUrl":"10.1016/j.cemconcomp.2025.106283","url":null,"abstract":"<div><div>Magnesium phosphate cement paste (MPC) has garnered significant attention as a promising material for rapid repair applications. Nevertheless, MPC-based composites exhibit suboptimal freeze–thaw (F-T) durability, and comprehensive quantitative insights into the degradation evolution and underlying deterioration mechanisms induced by F-T cycling are still lacking. In this study, we present a novel approach by integrating high-resolution non-destructive X-ray computed tomography (X-CT) with digital volume correlation (DVC) techniques to elucidate the structural degradation pathways and mechanisms of hardened MPC paste from a three-dimensional (3D) quantitative characterization perspective. The experimental findings reveal that F-T cycles alter the failure mode of MPC specimens, transitioning from a tensile–shear mixed mechanism to a tensile-dominated failure. The application of confining pressure notably enhances the fracture toughness of the material and promotes a shift towards shear-driven failure modes. F-T induced degradation exhibits a pronounced spatial gradient, initiating at the specimen periphery and propagating inward. Concurrently, substantial morphological transformations of pores are observed, with degradation regions evolving from a dispersed distribution to localized concentration. Moreover, the chemical dissolution of K-struvite crystals enlarges internal pores and enhances the connectivity of the pore network, thereby promoting the migration and accumulation of capillary water. This phenomenon intensifies freeze-induced expansion due to water–ice phase transitions at low temperatures, significantly accelerating the structural deterioration of MPC.</div></div>","PeriodicalId":9865,"journal":{"name":"Cement & concrete composites","volume":"164 ","pages":"Article 106283"},"PeriodicalIF":13.1,"publicationDate":"2025-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144840347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Properties of green ultra-high performance sulfoaluminate cement concrete incorporating recycled sand under sustained low temperature curing 含再生砂的绿色超高性能硫铝酸盐水泥混凝土的低温持续养护性能

IF 13.1 1区工程技术

Cement & concrete composites Pub Date : 2025-08-13 DOI: 10.1016/j.cemconcomp.2025.106291

Yang Meng , Danying Gao , Lin Yang , Jinqian Fang

{"title":"Properties of green ultra-high performance sulfoaluminate cement concrete incorporating recycled sand under sustained low temperature curing","authors":"Yang Meng , Danying Gao , Lin Yang , Jinqian Fang","doi":"10.1016/j.cemconcomp.2025.106291","DOIUrl":"10.1016/j.cemconcomp.2025.106291","url":null,"abstract":"<div><div>In this paper, green ultra-high performance sulfoaluminate cement concrete incorporating recycled sand (GS-UHPC) was developed, and its low temperature properties were studied. The setting time, hydration phases, internal temperature, pore structure, micromorphology, compressive strength, and flexural performance of GS-UHPC cured at 20 °C, 10 °C, 2 °C, −5 °C, and −10 °C were comprehensively evaluated. Meanwhile, digital image correlation and acoustic emission techniques were used for analysis. Results suggested that the curing temperature had a limited effect on the rapid setting characteristic of GS-UHPC. However, as the temperature dropped from 20 °C to −10 °C, the hydration rate and hydration degree progressively declined. For GS-UHPC cured at 2 °C, the microstructure deteriorated relative to that cured at 20 °C and 10 °C, forming more less-harmful and harmful pores, which slightly increased the total porosity. At −5 °C and −10 °C, a substantial amount of unhydrated phases remained in GS-UHPC, and the proportion of more-harmful pores increased obviously, but the hydration reaction continued with prolonged curing, gradually improving the microstructure. Therefore, although the mechanical strength, toughness, and crack resistance of GS-UHPC were reduced at low temperatures, these properties still showed rapid enhancement within the first 4 hours and 3 days of curing, and steadily improved over time. For example, the compressive and flexural strengths at 28 d decreased from 121.1 MPa and 19.36 MPa at 20 °C to 62.2 MPa and 12.14 MPa at −10 °C. Notably, at −10 °C, the compressive and flexural strengths reached 15.1 MPa and 5.89 MPa at 4 h, and 31.4 MPa and 8.32 MPa at 3 d, respectively. These findings reflect the distinctive low temperature performances of GS-UHPC, indicating its good application prospects for engineering construction and repair in cold regions.</div></div>","PeriodicalId":9865,"journal":{"name":"Cement & concrete composites","volume":"164 ","pages":"Article 106291"},"PeriodicalIF":13.1,"publicationDate":"2025-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144824859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Fractal modeling on the effective thermal conductivity of aerogels incorporated cementitious composites (AICC) incorporating the ITZ effects 考虑ITZ效应的气凝胶胶凝复合材料（AICC）有效导热系数的分形建模

IF 13.1 1区工程技术

Cement & concrete composites Pub Date : 2025-08-11 DOI: 10.1016/j.cemconcomp.2025.106290

Wenting Li, Qiyu Zhang, Zhendong Yang, Hongen Zhang, Bei He, Zhengwu Jiang

{"title":"Fractal modeling on the effective thermal conductivity of aerogels incorporated cementitious composites (AICC) incorporating the ITZ effects","authors":"Wenting Li, Qiyu Zhang, Zhendong Yang, Hongen Zhang, Bei He, Zhengwu Jiang","doi":"10.1016/j.cemconcomp.2025.106290","DOIUrl":"10.1016/j.cemconcomp.2025.106290","url":null,"abstract":"<div><div>Recent research has increasingly focused on the application of aerogels in cementitious composites, given their exceptional thermal insulation properties despite their relatively low mechanical strength. Aerogels incorporated cementitious composites (AICC) presents a potential solution for achieving a balance between superior thermal insulation and enhanced mechanical performance. This study proposes a prediction model based on the configuration of the three-phase Sierpinski carpet model for the effective thermal conductivity of AICC by innovatively incorporating the interfacial transition zone (ITZ) effect. A parametric analysis was systematically conducted and the results were validated against experimental data for aerogel incorporated ultra high-performance concrete (AIUHPC), mortar (AIM) and paste (AIP). The selection of either constant <em>C</em> or <em>n</em> in calculation and the effect of ITZ properties (i.e., thermal conductivity, porosity and thickness) on the predicted results were mainly discussed. The results indicate that using a constant <em>C</em> is more appropriate for low content of aerogels, while the algorithm by constant <em>n</em> demonstrates more accurate results for the higher content of aerogels (50 vol%∼). The thermal conductivity of ITZ is more significantly affected by the disparity in thermal conductivity between the matrix and the aerogels than by the aerogel size. The impact of aerogels addition on the fractal dimension of AICC is more pronounced at aerogel content higher than 40 vol%. By explicitly considering the influence of ITZ, the enhanced ITZ-incorporated tri-phase carpet model achieves ≤10 % prediction error for AICC thermal conductivity, highlighting the critical role of interfacial effects in the composite.</div></div>","PeriodicalId":9865,"journal":{"name":"Cement & concrete composites","volume":"164 ","pages":"Article 106290"},"PeriodicalIF":13.1,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144819240","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Functionalization of lightweight two-stage concrete composite (LTSCC) for thermal energy storage 轻质两级混凝土复合材料（LTSCC）储热功能化研究

IF 13.1 1区工程技术

Cement & concrete composites Pub Date : 2025-08-11 DOI: 10.1016/j.cemconcomp.2025.106288

Fan Zheng, Hailong Ye

{"title":"Functionalization of lightweight two-stage concrete composite (LTSCC) for thermal energy storage","authors":"Fan Zheng, Hailong Ye","doi":"10.1016/j.cemconcomp.2025.106288","DOIUrl":"10.1016/j.cemconcomp.2025.106288","url":null,"abstract":"<div><div>Integrating phase change material (PCM) in concrete can enhance building energy efficiency. This study functionalized lightweight two-stage concrete composites (LTSCC) for thermal energy storage by incorporating PCM-loaded foam glass aggregates (PFGA), which eliminated the damage and segregation issues of the PCM carriers that frequently occurred in existing methods. The PFGAs physically loaded with PCM were first preplaced and infiltrated with a highly flowable lightweight slurry to produce LTSCC. By adjusting the volume ratios of the PFGA, functionalized LTSCC of varying strength grades was produced, achieving a maximum 28-day compressive strength of 52.6 MPa at an air-dried density of 2077.6 kg/m<sup>3</sup>, with thermal conductivity under 1.547 W/(m·K). With the incorporation of the PFGA, room model tests revealed the superior temperature regulation performance of the fabricated LTSCC, achieving a significant reduction in indoor temperature difference (down to ∼10 °C). Finally, a long-term reliability test was conducted, in which geometrical, mechanical, and thermal properties were characterized before and after 360 thermal cycles, along with microstructure observations. The comparative analysis demonstrated the stable performance of the functionalized LTSCC, with self-desiccation identified as the primary cause of the minor property changes. The radar chart analysis of the collective results indicated that the functionalized LTSCC effectively balanced lightweight properties, strength requirements, and thermal energy storage, with an optimal PFGA volume ratio of 2/3.</div></div>","PeriodicalId":9865,"journal":{"name":"Cement & concrete composites","volume":"164 ","pages":"Article 106288"},"PeriodicalIF":13.1,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144813319","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Monitoring the water saturation and damage in reinforced concrete subjected to alkali-silica reaction gradient by non-destructive testing 用无损检测方法监测碱-硅反应梯度下钢筋混凝土的含水饱和度和损伤

IF 13.1 1区工程技术

Cement & concrete composites Pub Date : 2025-08-11 DOI: 10.1016/j.cemconcomp.2025.106287

Goodluck Msigwa, Narintsoa Ranaivomanana, Stéphane Multon

{"title":"Monitoring the water saturation and damage in reinforced concrete subjected to alkali-silica reaction gradient by non-destructive testing","authors":"Goodluck Msigwa, Narintsoa Ranaivomanana, Stéphane Multon","doi":"10.1016/j.cemconcomp.2025.106287","DOIUrl":"10.1016/j.cemconcomp.2025.106287","url":null,"abstract":"<div><div>Alkali silica reaction (ASR) is a harmful swelling pathology in concrete influenced by various factors such as moisture levels and stress conditions. In order to evaluate ASR-damaged structures, it is essential to characterize in situ water saturation gradients and to quantify the influence of reinforcement on ASR-induced damage. This research aims to assess the capability of different non-destructive testing (NDT) methods to evaluate moisture gradients in the context of ASR as well as the damage arising from expansion gradients in presence of reinforcement. Plain and reinforced concrete specimens were cast using both reactive and control composition. After curing, the specimens were fully, half-immersed and quarter-immersed in water at 38 °C to monitor the effects of ASR under varying water saturation conditions. The physicochemical conditions were characterized using permittivity tests. Expansion and damage were monitored through two-dimensional length change measurements, linear vibration analysis, acoustic emission (AE) and crack observations. This paper proposes an original method involving AE monitoring during mechanical loading following expansion. The linear vibration method was found to correlate the extent of damage with average expansion, regardless of the moisture gradient or presence of reinforcement. The acoustic emission during mechanical loading, along with crack observation techniques, effectively localized damage resulting from moisture gradients and reinforcement effects. The discussion highlights the complementary nature of these two techniques for monitoring the damage in both plain and reinforced concrete subjected to ASR.</div></div>","PeriodicalId":9865,"journal":{"name":"Cement & concrete composites","volume":"164 ","pages":"Article 106287"},"PeriodicalIF":13.1,"publicationDate":"2025-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144813364","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0