Cement and Concrete Research最新文献

{"title":"In-situ XRD study of the effects of amino acids on the carbonation kinetics of cementitious calcium silicates","authors":"Ziyu Chen ,&nbsp;Tian Zhang ,&nbsp;Yuxiang Wu ,&nbsp;Ian Madsen ,&nbsp;Jisheng Ma ,&nbsp;Kwesi Sagoe-Crentsil ,&nbsp;Adrian Neild ,&nbsp;Wenhui Duan","doi":"10.1016/j.cemconres.2025.107879","DOIUrl":"10.1016/j.cemconres.2025.107879","url":null,"abstract":"<div><div>The carbonation of cementitious calcium silicates, specifically tricalcium silicate (C₃S) and dicalcium silicate (C₂S), is crucial for Carbon Capture and Utilization (CCU) in reducing CO₂ emissions in the cement and concrete industry. Controlling these reactions, including the rate and phase evolution necessary for producing desirable carbonated products, poses significant challenges. A lack of continuous kinetic data has impeded the understanding of the mechanisms behind carbonation and its optimization to enhance efficiency. This study explores the effects of four amino acids—glycine, L-arginine, sarcosine, and <span>l</span>-serine—on the carbonation of calcium silicate using in-situ XRD for real-time data collection. It identified a three-stage carbonation process starting with an induction period. The presence of specific amino acids encouraged the formation of stable vaterite and denser microstructures, indicating their potential to enhance the mechanical properties and durability of cementitious materials.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"193 ","pages":"Article 107879"},"PeriodicalIF":10.9,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143688027","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dual dynamic regulation mechanism of trace calcium phosphate on hydration of cementitious materials and optimization of pore structure","authors":"Lei Wu ,&nbsp;Jin Zhong ,&nbsp;Zhe Sun ,&nbsp;Yan Cao","doi":"10.1016/j.cemconres.2025.107875","DOIUrl":"10.1016/j.cemconres.2025.107875","url":null,"abstract":"<div><div>This study explores the regulatory mechanisms of trace calcium phosphate (CaP) in the hydration of Portland cement. The results indicate that incorporating 0.001 wt% CaP extends the induction period by forming a passivation film while simultaneously accelerating the hydration rate during the acceleration phase as a nucleation agent, thereby improving hydration efficiency and uniformity. CaP enhances the polymerization degree and homogeneity of C-S-H gel. It modulates the formation and distribution of Ca(OH)₂, facilitating a controlled transition of the crystal structure from a chain-like configuration to layered or network-like forms, thereby enhancing stability. Furthermore, this study highlights the distinct roles of CaP in fresh and aged cement systems and proposes a multi-scale mechanism for complex hydration processes. These findings offer valuable theoretical insights and practical guidance for applying CaP in cementitious materials.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"193 ","pages":"Article 107875"},"PeriodicalIF":10.9,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143687951","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}

{"title":"Novel strategies for ultra-early strengthening of shotcrete: Stage-wise kinetic control of hydration products","authors":"Hui Xie ,&nbsp;Xin Liu ,&nbsp;Haochuan Wang ,&nbsp;Zhenqi Yu ,&nbsp;Lijing Shao ,&nbsp;Wei Wang ,&nbsp;Jinxiang Hong ,&nbsp;Chong Wang ,&nbsp;Pan Feng","doi":"10.1016/j.cemconres.2025.107880","DOIUrl":"10.1016/j.cemconres.2025.107880","url":null,"abstract":"<div><div>The use of aluminum sulfate (Al₂(SO₄)₃)-based alkali-free accelerators in shotcrete often impeded tricalcium silicate (C₃S) hydration, leading to poor ultra-early strength development. To address this, a novel stage-wise kinetic control strategy was proposed to regulate the sequential formation of ettringite and C-S-H gel through the delayed addition of C-S-H nano seeds. The dosage of C-S-H nano seeds, delayed time, addition sequence of Al₂(SO₄)₃ and C-S-H nano seeds were carefully examined in this study, and the effects of addition sequence on the hydration kinetic, hydration products, and pore structure of cement pastes were systematically investigated. Results demonstrated a significant enhancement in 6 h compressive strength, achieving a 35% increase when C-S-H nano seeds (4% dosage) were added 1 h after initial mixing compared to simultaneous addition. Hydration heat, XRD, TG, SEM, and BSE-EDS analyses revealed that the delayed addition promoted C₃S hydration at later stages by staggering intensive ettringite formation and C-S-H gel precipitation, mitigating competition for calcium ions. This stage-wise approach facilitated C-S-H gel integration into the pre-constructed porous ettringite skeleton, refining the pore structure and enhancing ultra-early mechanical performance. These findings highlight an effective strategy to optimize hydration kinetics and strength development in shotcrete applications.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"193 ","pages":"Article 107880"},"PeriodicalIF":10.9,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143697332","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}

{"title":"Crystallization pressure in ASR expansion quantified by thermodynamic modeling and micromechanics","authors":"Syrine Razki ,&nbsp;Farid Benboudjema ,&nbsp;Alexandra Bourdot ,&nbsp;Sylvain Langlois ,&nbsp;Amélie Fau ,&nbsp;Fikri Hafid ,&nbsp;Tulio Honorio","doi":"10.1016/j.cemconres.2025.107878","DOIUrl":"10.1016/j.cemconres.2025.107878","url":null,"abstract":"<div><div>Establishing direct relations between alkali-silica reaction (ASR) expansion, crystallization pressure build-up, and phase assemblage changes is a critical step towards predictive modeling of ASR damage. To address this, we propose a strategy that combines thermodynamic modeling with micromechanics. First, we complete the thermodynamic database for ASR products, including nanocrystalline ASR-P1 data and improving the previous data for crystalline products. Phase assemblage is determined by accounting for cement hydration and amorphous silica dissolution kinetics. Crystallization pressure estimates are provided based on pore solution supersaturation with respect to ASR products. These phase assemblage and crystallization pressure estimates are then used as input for analytical micromechanical estimates of elastic properties degradation and macroscopic expansion. The model strategy that integrates damage considerations and the gel-like nature of ASR-P1 provides a better comparison with experimental results.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"193 ","pages":"Article 107878"},"PeriodicalIF":10.9,"publicationDate":"2025-03-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143675499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A thermo-hygro model to determine the factors dictating cold joint formation in 3D printed concrete","authors":"Michal Hlobil,&nbsp;Luca Michel,&nbsp;Mohit Pundir,&nbsp;David S. Kammer","doi":"10.1016/j.cemconres.2025.107869","DOIUrl":"10.1016/j.cemconres.2025.107869","url":null,"abstract":"<div><div>Cold joints in extruded concrete structures form once the exposed surface of a deposited filament dries prematurely and gets sequentially covered by a layer of fresh concrete. This creates a material heterogeneity which lowers the structural durability and shortens the designed service life. Many factors concurrently affect cold joint formation, yet a suitable tool for their categorization is missing. Here, we present a computational model that simulates the drying kinetics at the exposed structural surface, accounting for cement hydration and the resulting microstructural development. The model provides a time estimate for cold joint formation as a result. It allows us to assess the drying severity for a given geometry of the structure, its interaction with the environment, and ambient conditions. We evaluate the assessed factors and provide generalized recommendations for cold joint mitigation.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"193 ","pages":"Article 107869"},"PeriodicalIF":10.9,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143666463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Revealing the morphology of nano-ettringite in cement paste: A TEM study on the influence of polycarboxylate ether superplasticizers","authors":"Olivia Rindle ,&nbsp;Florian Sixt ,&nbsp;Liam Spillane ,&nbsp;Elena Willinger ,&nbsp;Torben Gädt","doi":"10.1016/j.cemconres.2025.107853","DOIUrl":"10.1016/j.cemconres.2025.107853","url":null,"abstract":"<div><div>Ettringite forms directly after Portland cement is mixed with water. Polycarboxylate ether-type superplasticizers can stabilize nano-ettringite particles in the pore solution and modify ettringite formation. It was previously impossible to isolate the nano-ettringite from the cement pore solution at commonly used water-to-cement (w/c) ratios of 0.5 and lower. Therefore, the exact morphology of ettringite in the pore solution has not been systematically studied. This paper presents a novel method for obtaining nano-ettringite from cement paste by centrifugation with a high-density liquid. Ettringite was isolated at three different water-to-cement ratios (0.3, 0.4, and 0.5) and four dosages of a polycarboxylate ether-type superplasticizer (0.05%, 0.1%, 0.25%, and 0.4%). The size and morphology of the obtained ettringite particles were analyzed using transmission electron microscopy (TEM). The chemical composition and structure of ettringite were confirmed using electron energy loss spectroscopy, high-resolution TEM imaging, and X-ray diffraction. The ettringite particle size decreases as the superplasticizer dosage increases. As a result, the specific surface area at higher superplasticizer dosages increases from 39<!--> <!-->m² <!-->g⁻¹ to 58<!--> <!-->m² <!-->g⁻¹. In-situ calorimetry was used to measure the initial heat release and estimate the amount of ettringite formed. Since the initial heat did not change significantly with varying superplasticizer dosages, it suggests that the studied superplasticizer has a minor influence on the amount of ettringite at the considered concentrations. In summary, cement paste centrifugation using a high-density fluid allows the isolation of superplasticizer-stabilized nano-ettringite from cement paste. The method could be valuable for other studies dealing with the impact of ettringite morphology.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"193 ","pages":"Article 107853"},"PeriodicalIF":10.9,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143660436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of time-resolved water distribution and paramagnetic contents migration during alkali-activation process of Metakaolin using PD-MRI","authors":"Zian Tang ,&nbsp;Yuanrui Song ,&nbsp;Wenyu Li","doi":"10.1016/j.cemconres.2025.107871","DOIUrl":"10.1016/j.cemconres.2025.107871","url":null,"abstract":"<div><div>The alkali-activation process is known to be rapid and thus challenging to characterize. In this work, we used proton density magnetic resonance imaging (PD-MRI) to observe the water distribution during the alkali-activation process of metakaolin. With the obtained visible brightness changing of the solid phase and the bled water, the setting time of the alkali-activated materials (AAMs) can be determined, while the migration of paramagnetic contents (Fe) and the accumulation of unreacted base can be traced. Moreover, the total shrinkage of the activated paste was calculated for the first time based on MRI in this manuscript. The results show the potential use of this technique for characterizing AAMs with lower paramagnetic content.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"193 ","pages":"Article 107871"},"PeriodicalIF":10.9,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143640560","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}

{"title":"Hierarchical pore structure for enhanced carbonation in basic magnesium sulfate cement: Mechanisms from modification to post‑carbonation evolution","authors":"Junjie You ,&nbsp;Yanrong Zhang ,&nbsp;Cheng Yang ,&nbsp;Qianyi Song ,&nbsp;Yi Sun","doi":"10.1016/j.cemconres.2025.107876","DOIUrl":"10.1016/j.cemconres.2025.107876","url":null,"abstract":"<div><div>Basic magnesium sulfate cement (BMSC) contains excess MgO causing volume instability, limiting its applications. Although forced carbonation stabilizes MgO into carbonates, it compromises strength by transforming strength-contributing phases. This study presents a forced carbonation strategy based on hierarchical pore regulation. We constructed a multi-scale pore network from nano to macro scale, optimizing CO₂ diffusion channels and carbonation product deposition space through synergy of basalt fiber and recycled wood fiber. The system exhibits a three-stage mechanism during forced carbonation: pressure-driven dissolution, filling-directed reconstruction, and self-regulating evolution. Under this mechanism, the developed carbonated bio-based magnesium sulfate (CBMS) cement overcame post‑carbonation limitations and exhibited increases of 79.3% and 19.1% in compressive and flexural strength respectively through the synergistic effect of fiber toughening and carbonation filling. The coupling mechanism between hierarchical pore structure evolution and carbonation behavior further achieved a 215.3% increase in carbonation degree and a 59.9% reduction in global warming potential.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"193 ","pages":"Article 107876"},"PeriodicalIF":10.9,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143635369","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}

{"title":"An experimental and numerical study on the cracking of alkali-activated slag pastes induced by water immersion","authors":"Chen Liu ,&nbsp;Jinbao Xie ,&nbsp;Zhenming Li ,&nbsp;Guang Ye","doi":"10.1016/j.cemconres.2025.107877","DOIUrl":"10.1016/j.cemconres.2025.107877","url":null,"abstract":"<div><div>Cementitious materials can achieve desirable strength development and reduced cracking potential under moist or immersed conditions. However, in this work, we found that alkali-activated slag (AAS) pastes can crack underwater, with a higher silicate modulus showing more pronounced cracking. Chemically, the C-(N-)A-S-H gel in the paste with a higher silicate modulus showed a higher Na/Si ratio and a higher leaching loss of Na, which led to more significant structural changes and gel deterioration underwater. This triggered the propagation of cracks initially present in the material. Physically, the paste with a higher silicate modulus featured a denser microstructure, lower water permeability and higher pore pressure, which resulted in a steeper gradient of pore pressure in the matrix. Consequently, the concentration of tensile stress was simulated at the centre and the corner of the cross-section of the sample. As this simulated concentrated stress exceeded the flexural strength of AAS pastes, significant fractures at the centre and spalling at the corner occurred, consistent with the experimental observation. This work not only elucidated the cracking mechanisms of AAS materials underwater but also provided new insights into mixture designs for these materials under high-humidity conditions.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"193 ","pages":"Article 107877"},"PeriodicalIF":10.9,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143635360","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Phase evolution of cement raw meal in a high-CO2 atmosphere","authors":"José Aguirre Castillo ,&nbsp;Bodil Wilhelmsson ,&nbsp;Markus Broström ,&nbsp;Matias Eriksson","doi":"10.1016/j.cemconres.2025.107874","DOIUrl":"10.1016/j.cemconres.2025.107874","url":null,"abstract":"<div><div>This study investigates the effects of a high-CO₂ atmosphere on phase evolution, burnability, and clinker mineral formation in cement raw meals using high-temperature X-ray diffraction (HT-XRD). The cement industry is a significant CO₂ emitter, primarily from limestone decomposition and fuel combustion. Innovative solutions such as carbon capture and storage (CCS) are critical, with electrification and oxy-fuel combustion showing promise. Electrification using plasma technology, which employs CO₂ as a carrier gas, offers a pathway to near-zero emissions.</div><div>Four industrial raw meals from northern Europe were analyzed under conventional (20% CO₂) and high-CO₂ (95% CO₂) conditions. Chemical composition, particle size distribution, and coarse fraction analyses preceded HT-XRD data collection across temperatures up to 1500 °C. High-CO₂ conditions delayed calcite decomposition, reducing free-CaO availability and altering burnability. The timing of calcite decomposition relative to C₂S formation suggests a reaction pathway in which free CaO, released from calcite, rapidly reacts with thermally activated SiO₂ to form C₂S. Additionally, spurrite decomposition released reactive CaO and C₂S, enhancing C₃S formation at 1300–1400 °C in spurrite-rich samples. Above 1400 °C, melt formation promoted further C₃S development, leading to similar final levels in both tested atmospheres.</div><div>These findings indicate that high-CO₂ conditions significantly influence clinker phase evolution and reactivity. Practical implications include optimizing raw meal composition and kiln temperature profiles in electrified and oxy-fuel systems to enhance burnability while minimizing operational issues such as spurrite-induced kiln buildup. Future research should further explore industrial scalability and raw material adjustments to enhance CO₂ efficiency during clinkerization.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"193 ","pages":"Article 107874"},"PeriodicalIF":10.9,"publicationDate":"2025-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143618620","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}