Pub Date : 2025-11-26DOI: 10.1016/j.cemconres.2025.108089
Shengnan Sha, Sirajuddin Moghul, Robert J. Flatt
The timing of superplasticizer addition is known to impact both the yield stress and hydration kinetics of cementitious systems. Recent results demonstrate that these changes can be directly related to changes in the specific surface area of the cement paste. As this results from a change in hydrate morphology, in particular ettringite, two main reasons may explain yield stress changes in relation to addition time.
On the one hand, these may result from changes in adsorption. On the other hand, they may be due to changes in the maximum packing of the cement paste. To examine both scenarios, we have applied the YODEL, a Yield Stress mODEL that has been recognized as an effective model for predicting the yield stress of cement-based materials.
By doing this, we could evaluate the relative roles of changes in adsorption and of maximum packing in cement-limestone pastes. Results indicate that, in the range of yield stresses and volume fractions measurable in our experiments, changes in adsorption, rather than variations in maximum packing, are the primary difference between direct and delayed addition.
{"title":"New insights into the role of superplasticizer addition time on yield stress of cementitious materials","authors":"Shengnan Sha, Sirajuddin Moghul, Robert J. Flatt","doi":"10.1016/j.cemconres.2025.108089","DOIUrl":"10.1016/j.cemconres.2025.108089","url":null,"abstract":"<div><div>The timing of superplasticizer addition is known to impact both the yield stress and hydration kinetics of cementitious systems. Recent results demonstrate that these changes can be directly related to changes in the specific surface area of the cement paste. As this results from a change in hydrate morphology, in particular ettringite, two main reasons may explain yield stress changes in relation to addition time.</div><div>On the one hand, these may result from changes in adsorption. On the other hand, they may be due to changes in the maximum packing of the cement paste. To examine both scenarios, we have applied the YODEL, a Yield Stress mODEL that has been recognized as an effective model for predicting the yield stress of cement-based materials.</div><div>By doing this, we could evaluate the relative roles of changes in adsorption and of maximum packing in cement-limestone pastes. Results indicate that, in the range of yield stresses and volume fractions measurable in our experiments, changes in adsorption, rather than variations in maximum packing, are the primary difference between direct and delayed addition.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"200 ","pages":"Article 108089"},"PeriodicalIF":13.1,"publicationDate":"2025-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145598619","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}
This study examines the microstructural evolution and changes in the properties of C–S–H in a cement paste hydrated at elevated temperatures ranging from 110 to 190 C. Using a simple slurry formulation composed only of Class G cement and water, the material’s evolution was quantitatively investigated through a multi-technique approach, including mechanical testing (UCT), microstructural analysis (MIP), and chemical characterization (TGA and XRD). The results reveal two key mechanisms driving the observed strength loss: (1) a significant increase in porosity and pore size over time, leading to microstructural coarsening, and (2) the formation of denser crystalline phases with higher C/S ratios (over 2). Estimations of the C/S ratio and density of the amorphous C–S–H indicate its progressive decalcification and densification, with the lowest C/S values observed at the highest curing temperatures. This work extends previous studies on the quantitative characterization of Class G cement paste hydrated between 7 and 90 C (Bahafid et al., 2017, 2018), offering a comprehensive understanding of microstructural evolution over a broad temperature range - from 7 to 190 C - during hydration.
本研究考察了在110至190°C高温下水化的水泥浆中C - s - h的微观结构演变和性能变化。采用仅由G类水泥和水组成的简单泥浆配方，通过多种技术方法定量研究了材料的演变，包括力学测试（UCT）、微观结构分析（MIP）和化学表征（TGA和XRD）。结果揭示了导致强度损失的两个关键机制：(1)随着时间的推移，孔隙率和孔径显著增加，导致微观结构粗化；(2)形成更高C/S比（大于2）的致密晶相。对非晶C - S - h的C/S比和密度的估计表明，非晶C - S - h逐渐脱钙和致密化，在最高的固化温度下，C/S值最低。这项工作扩展了之前关于G类水泥浆在7到90°C间水化的定量表征的研究（Bahafid et al., 2017,2018），对水化过程中在7到190°C的大温度范围内的微观结构演变有了全面的了解。
{"title":"Effect of the hydration temperature between 110 and 190 ∘C on the microstructure of Class G cement: Phase composition, pore structure and C–S–H chemistry","authors":"Axelle Alavoine , Math Lecomte , Mickael Saillio , Myriam Duc , Siavash Ghabezloo","doi":"10.1016/j.cemconres.2025.108093","DOIUrl":"10.1016/j.cemconres.2025.108093","url":null,"abstract":"<div><div>This study examines the microstructural evolution and changes in the properties of C–S–H in a cement paste hydrated at elevated temperatures ranging from 110 to 190 <span><math><msup><mrow></mrow><mrow><mo>∘</mo></mrow></msup></math></span>C. Using a simple slurry formulation composed only of Class G cement and water, the material’s evolution was quantitatively investigated through a multi-technique approach, including mechanical testing (UCT), microstructural analysis (MIP), and chemical characterization (TGA and XRD). The results reveal two key mechanisms driving the observed strength loss: (1) a significant increase in porosity and pore size over time, leading to microstructural coarsening, and (2) the formation of denser crystalline phases with higher C/S ratios (over 2). Estimations of the C/S ratio and density of the amorphous C–S–H indicate its progressive decalcification and densification, with the lowest C/S values observed at the highest curing temperatures. This work extends previous studies on the quantitative characterization of Class G cement paste hydrated between 7 and 90 <span><math><msup><mrow></mrow><mrow><mo>∘</mo></mrow></msup></math></span>C (Bahafid et al., 2017, 2018), offering a comprehensive understanding of microstructural evolution over a broad temperature range - from 7 to 190 <span><math><msup><mrow></mrow><mrow><mo>∘</mo></mrow></msup></math></span>C - during hydration.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"200 ","pages":"Article 108093"},"PeriodicalIF":13.1,"publicationDate":"2025-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145575225","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}
Pub Date : 2025-11-21DOI: 10.1016/j.cemconres.2025.108090
Chancel Mawalala Moundounga , Wahab Abdul , Alexander Pisch , Gavin B.G. Stenning , Cecilia Pesce , Theodore Hanein
Ternesite (Ca5(SiO4)2SO4) is a cementitious phase that can be found in the production of calcium sulfoaluminate (CSA) based cements and other alternative binders. Ternesite has received interest due to its potential hydraulic reactivity (under certain conditions) whilst having a low temperature of formation. Despite this, the ternesite phase is not thermodynamically well understood, reducing the ability to accurately model its formation, stability and phase co-existence in clinker. In this work, pure ternesite was synthesised and the high temperature heat content (874–1174 K) and low temperature heat capacity (2−302K) was measured using drop calorimetry and PPMS respectively. These data were then combined with enthalpy of formation results from DFT and previous experiments to model the thermodynamics properties of ternesite using the 3rd generation CALPHAD function. This allows for a single function to describe the thermodynamic properties of ternesite for use in extending existing thermodynamic databases as part of predictive calculations at a temperature range from 0 K to above the clinkering temperature.
{"title":"Thermodynamic properties of ternesite (Ca5(SiO4)2SO4) from 0 K up to clinkering temperatures","authors":"Chancel Mawalala Moundounga , Wahab Abdul , Alexander Pisch , Gavin B.G. Stenning , Cecilia Pesce , Theodore Hanein","doi":"10.1016/j.cemconres.2025.108090","DOIUrl":"10.1016/j.cemconres.2025.108090","url":null,"abstract":"<div><div>Ternesite (Ca<sub>5</sub>(SiO<sub>4</sub>)<sub>2</sub>SO<sub>4</sub>) is a cementitious phase that can be found in the production of calcium sulfoaluminate (CSA) based cements and other alternative binders. Ternesite has received interest due to its potential hydraulic reactivity (under certain conditions) whilst having a low temperature of formation. Despite this, the ternesite phase is not thermodynamically well understood, reducing the ability to accurately model its formation, stability and phase co-existence in clinker. In this work, pure ternesite was synthesised and the high temperature heat content (874–1174 K) and low temperature heat capacity (2−302<em>K</em>) was measured using drop calorimetry and PPMS respectively. These data were then combined with enthalpy of formation results from DFT and previous experiments to model the thermodynamics properties of ternesite using the 3rd generation CALPHAD function. This allows for a single function to describe the thermodynamic properties of ternesite for use in extending existing thermodynamic databases as part of predictive calculations at a temperature range from 0 K to above the clinkering temperature.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"200 ","pages":"Article 108090"},"PeriodicalIF":13.1,"publicationDate":"2025-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145567521","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}
Pub Date : 2025-11-19DOI: 10.1016/j.cemconres.2025.108091
Xiao Xu , Shijie Wang , Haifeng Qin , Zhiqiang Zhao , Zheyong Fan , Zhuhua Zhang , Hang Yin
Tobermorite and Calcium Silicate Hydrate (C-S-H) systems are indispensable cement materials but still lack a satisfactory interatomic potential with both high accuracy and high computational efficiency for better understanding their mechanical performance. Here, we develop a Neuroevolution Machine Learning Potential (NEP) with Ziegler-Biersack-Littmark hybrid framework for tobermorite and C-S-H systems, which conveys unprecedented efficiency in molecular dynamics simulations with substantially reduced training datasets. Our NEP model achieves prediction accuracy comparable to DFT calculations using just around 400 training structures, significantly fewer than other existing machine learning potentials trained for tobermorite. Critically, the GPU-accelerated NEP computations enable scalable simulations of large tobermorite systems, reaching several thousand atoms per GPU card with high efficiency. We demonstrate the NEP's versatility by accurately predicting mechanical properties, phonon density of states, and thermal conductivity of tobermorite. Furthermore, we extend the NEP application to large-scale simulations of amorphous C-S-H, highlighting its potential for comprehensive analysis of structural and mechanical behaviors under various realistic conditions.
{"title":"A high-efficiency neuroevolution potential for tobermorite and calcium silicate hydrate systems with ab initio accuracy","authors":"Xiao Xu , Shijie Wang , Haifeng Qin , Zhiqiang Zhao , Zheyong Fan , Zhuhua Zhang , Hang Yin","doi":"10.1016/j.cemconres.2025.108091","DOIUrl":"10.1016/j.cemconres.2025.108091","url":null,"abstract":"<div><div>Tobermorite and Calcium Silicate Hydrate (C-S-H) systems are indispensable cement materials but still lack a satisfactory interatomic potential with both high accuracy and high computational efficiency for better understanding their mechanical performance. Here, we develop a Neuroevolution Machine Learning Potential (NEP) with Ziegler-Biersack-Littmark hybrid framework for tobermorite and C-S-H systems, which conveys unprecedented efficiency in molecular dynamics simulations with substantially reduced training datasets. Our NEP model achieves prediction accuracy comparable to DFT calculations using just around 400 training structures, significantly fewer than other existing machine learning potentials trained for tobermorite. Critically, the GPU-accelerated NEP computations enable scalable simulations of large tobermorite systems, reaching several thousand atoms per GPU card with high efficiency. We demonstrate the NEP's versatility by accurately predicting mechanical properties, phonon density of states, and thermal conductivity of tobermorite. Furthermore, we extend the NEP application to large-scale simulations of amorphous C-S-H, highlighting its potential for comprehensive analysis of structural and mechanical behaviors under various realistic conditions.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"200 ","pages":"Article 108091"},"PeriodicalIF":13.1,"publicationDate":"2025-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145554904","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}
Introducing metakaolin and sodium water glass (silicate modulus – 2.8, density – 1100...1250 kg/m3) to ordinary portland cement (OPC) caused fundamental changes to the hydration products, forming ones from Na₂O-CaO-SiO₂-Al₂O₃-H₂O system and enhancing heat resistance. The setting times of metakaolin-containing alkali-activated portland cement were rather short. The increased heat resistance of this cement compared to OPC was shown, which is due to no rehydration of CaO, formed during the dehydration of Ca(OH)2, and recrystallization of zeolite-like phase of hydronepheline Na2O·Al2O3·2SiO2·2H2O into nepheline Na2O·Al2O3·2SiO2 without structural destruction. The recrystallization of C-A-S-H phases during sintering into gehlenite 2CaO·Al2O3·SiO2 contributed to a higher structure fragmentation while its self-reinforcement. These processes resulted in an increase in residual strength to 58.6…122.1 %. The mortar based on the designed cement was characterized by compressive strength ≥30 MPa, residual strength ≥70 %, and thermal shrinkage ≤5 % at temperatures up to 1000 °C.
引进偏高岭土和水玻璃钠(硅酸盐模量- 2.8，密度- 1100…1250 kg/m3)转化为普通硅酸盐水泥（OPC），使水化产物发生根本性变化，形成Na₂- cao - sio₂-Al₂O₃-H₂O体系水化产物，提高了耐热性。偏高岭土碱活化硅酸盐水泥的凝结时间较短。与OPC相比，该水泥的耐热性有所提高，这是由于Ca(OH)2脱水过程中形成的CaO没有再水化，并且水辉石Na2O·Al2O3·2SiO2·2H2O的沸石样相重结晶为霞辉石Na2O·Al2O3·2SiO2而没有结构破坏。在烧结成2CaO·Al2O3·SiO2的过程中，C-A-S-H相的再结晶导致了较高的结构破碎和自增强。这些工艺使残余强度提高到58.6% ~ 122.1%。设计的水泥砂浆在高达1000℃的温度下，抗压强度≥30 MPa，残余强度≥70%，热收缩≤5%。
{"title":"Development of metakaolin-enhanced alkali-activated portland cement for high-temperature applications","authors":"Pavlo Kryvenko , Igor Rudenko , Oleksandr Konstantynovskyi , Vladyslav Onatii","doi":"10.1016/j.cemconres.2025.108088","DOIUrl":"10.1016/j.cemconres.2025.108088","url":null,"abstract":"<div><div>Introducing metakaolin and sodium water glass (silicate modulus – 2.8, density <em>–</em> 1100...1250 kg/m<sup>3</sup>) to ordinary portland cement (OPC) caused fundamental changes to the hydration products, forming ones from Na₂O-CaO-SiO₂-Al₂O₃-H₂O system and enhancing heat resistance. The setting times of metakaolin-containing alkali-activated portland cement were rather short. The increased heat resistance of this cement compared to OPC was shown, which is due to no rehydration of CaO, formed during the dehydration of Ca(OH)<sub>2</sub>, and recrystallization of zeolite-like phase of hydronepheline Na<sub>2</sub>O·Al<sub>2</sub>O<sub>3</sub>·2SiO<sub>2</sub>·2H<sub>2</sub>O into nepheline Na<sub>2</sub>O·Al<sub>2</sub>O<sub>3</sub>·2SiO<sub>2</sub> without structural destruction. The recrystallization of C-A-S-H phases during sintering into gehlenite 2CaO·Al<sub>2</sub>O<sub>3</sub>·SiO<sub>2</sub> contributed to a higher structure fragmentation while its self-reinforcement. These processes resulted in an increase in residual strength to 58.6…122.1 %. The mortar based on the designed cement was characterized by compressive strength ≥30 MPa, residual strength ≥70 %, and thermal shrinkage ≤5 % at temperatures up to 1000 °C.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"200 ","pages":"Article 108088"},"PeriodicalIF":13.1,"publicationDate":"2025-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145536224","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}
Pub Date : 2025-11-14DOI: 10.1016/j.cemconres.2025.108087
Jing Xie , Xuanhan Zhang , Xiang Hu , Zemei Wu , Caijun Shi
This study comprehensively investigates the mechanism by which temperature (5–40 °C) affects the air bubble behavior in belite-rich cement (BRC), comparing with portland cement (PC) system. Key factors, including surface tension, ionic strength, internal matrix temperature, viscosity, and cement particle-bubble/SDS interactions, were analyzed. Bubble generation efficiency in pore solution was enhanced with temperature due to reduced surface tension and increased ionic strength. Relational degree between initial bubble volume and ionic strength (0.8938) was higher than that with surface tension (0.7018) in pore solution. A “critical temperature” (CT) governed bubble drainage, coalescence, and Ostwald ripening. For BRC concrete, increasing temperature below CT of 26 °C enhanced bubble stability by strengthening viscosity and particle-bubble interactions, thereby lowering spacing factor. Above CT, excessive heat caused bubble expansion/rupture, increasing spacing factor. Notably, as indicated by its higher CT, BRC exhibited inferior low-temperature (≤12 °C) stability compared to PC but superior high-temperature stability.
{"title":"Insights into the temperature effect on air bubble behavior in belite-rich cement systems","authors":"Jing Xie , Xuanhan Zhang , Xiang Hu , Zemei Wu , Caijun Shi","doi":"10.1016/j.cemconres.2025.108087","DOIUrl":"10.1016/j.cemconres.2025.108087","url":null,"abstract":"<div><div>This study comprehensively investigates the mechanism by which temperature (5–40 °C) affects the air bubble behavior in belite-rich cement (BRC), comparing with portland cement (PC) system. Key factors, including surface tension, ionic strength, internal matrix temperature, viscosity, and cement particle-bubble/SDS interactions, were analyzed. Bubble generation efficiency in pore solution was enhanced with temperature due to reduced surface tension and increased ionic strength. Relational degree between initial bubble volume and ionic strength (0.8938) was higher than that with surface tension (0.7018) in pore solution. A “critical temperature” (CT) governed bubble drainage, coalescence, and Ostwald ripening. For BRC concrete, increasing temperature below CT of 26 °C enhanced bubble stability by strengthening viscosity and particle-bubble interactions, thereby lowering spacing factor. Above CT, excessive heat caused bubble expansion/rupture, increasing spacing factor. Notably, as indicated by its higher CT, BRC exhibited inferior low-temperature (≤12 °C) stability compared to PC but superior high-temperature stability.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"200 ","pages":"Article 108087"},"PeriodicalIF":13.1,"publicationDate":"2025-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145509624","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}
Pub Date : 2025-11-11DOI: 10.1016/j.cemconres.2025.108084
Liang-yu Tong , Qing-feng Liu , Elke Gruyaert , Natalia Mariel Alderete , Qing-xiang Xiong , Nele De Belie
Replacement of ordinary Portland cement (OPC) by blast-furnace slag (BFS) modifies the durability behaviour of concrete. Combined with the experimental tests, this study proposes a comprehensive framework for modelling carbonation in BFS concrete, integrating hydration, transport-reactive, and diffusivity predictive modules. The framework enables synchronized iterations between chemical reaction modelling and transport processes considering microstructural evolution over time. Each module is validated against prior experimental data, including the volume fraction of hydration products, trend-based diffusivities and carbonation depths. Compared with model that neglect microstructural evolution, this framework, which considers altered compositional profiles after hydration and dynamically adjusts transport properties in response to microstructural changes during carbonation, yields higher predictive accuracy. Results indicate that carbonation resistance in BFS concrete improves with extended curing durations due to more complete hydration and a denser microstructure. Conversely, higher BFS replacement levels reduce the concrete's CO₂ buffering capacity and increase gas diffusivity after carbonation, finally accelerating carbonation. Parametric analysis further identifies an optimal relative humidity range for BFS concrete at approximately 30 %–60 %, and rising CO₂ concentrations increase carbonation depth. This innovative approach not only improves the accuracy of carbonation predictions but also serves as a valuable tool for optimizing the durability and hence sustainability of BFS-based construction materials.
{"title":"Experimental and numerical study on carbonation of blast-furnace slag concrete considering the microstructural evolution","authors":"Liang-yu Tong , Qing-feng Liu , Elke Gruyaert , Natalia Mariel Alderete , Qing-xiang Xiong , Nele De Belie","doi":"10.1016/j.cemconres.2025.108084","DOIUrl":"10.1016/j.cemconres.2025.108084","url":null,"abstract":"<div><div>Replacement of ordinary Portland cement (OPC) by blast-furnace slag (BFS) modifies the durability behaviour of concrete. Combined with the experimental tests, this study proposes a comprehensive framework for modelling carbonation in BFS concrete, integrating hydration, transport-reactive, and diffusivity predictive modules. The framework enables synchronized iterations between chemical reaction modelling and transport processes considering microstructural evolution over time. Each module is validated against prior experimental data, including the volume fraction of hydration products, trend-based diffusivities and carbonation depths. Compared with model that neglect microstructural evolution, this framework, which considers altered compositional profiles after hydration and dynamically adjusts transport properties in response to microstructural changes during carbonation, yields higher predictive accuracy. Results indicate that carbonation resistance in BFS concrete improves with extended curing durations due to more complete hydration and a denser microstructure. Conversely, higher BFS replacement levels reduce the concrete's CO₂ buffering capacity and increase gas diffusivity after carbonation, finally accelerating carbonation. Parametric analysis further identifies an optimal relative humidity range for BFS concrete at approximately 30 %–60 %, and rising CO₂ concentrations increase carbonation depth. This innovative approach not only improves the accuracy of carbonation predictions but also serves as a valuable tool for optimizing the durability and hence sustainability of BFS-based construction materials.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"200 ","pages":"Article 108084"},"PeriodicalIF":13.1,"publicationDate":"2025-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145485705","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}
Pub Date : 2025-11-06DOI: 10.1016/j.cemconres.2025.108085
Yangrui Li , Yanfei Yue , Jueshi Qian , Yun Bai
The hydration inertness of ternesite (C5S2Š) is the primary barrier to the promotion of Ternesite-Ye'elimite Cement (TYC). This study investigated the potential of iron-doped calcium aluminates to activate the hydration of TYC systems, with particular focus on their roles in enhancing the reactivity of C5S2Š. Three types of calcium aluminates, viz. orthorhombic ye'elimite (C4A3Š), iron-doped cubic ye'elimite (C4(A,F)3Š) and ferrite (C4AF), as well as C5S2Š were synthesized in the laboratory. These four minerals, and three blends formulated by mixing each calcium aluminate with C5S2Š, were mixed with water to obtain a total of seven paste mixtures. Their hydration processes were examined using ICC, XRD, FT-IR, TG, and pore solution chemistry analysis to elucidate the influence of iron-doped calcium aluminates (C4(A,F)3Š and C4AF) on the hydration reactivity of C5S2Š and the corresponding mechanisms. Results show that C4(A,F)3Š significantly enhanced the hydration reactivity of C5S2Š by providing reactive amorphous (A,F)H3 to consume gypsum from the hydration of C5S2Š. Evidently, iron doping exhibited a gypsum-like acceleration effect on the hydration of C5S2Š + C4(A,F)3Š system, albeit through a distinct chemical pathway. However, C4AF demonstrated quite limited effect on the C5S2Š + C4AF system, due to the gradual formation of a gel layer on the C4AF surface that restricted further hydration.
{"title":"Can iron-doped calcium aluminates activate ternesite hydration?","authors":"Yangrui Li , Yanfei Yue , Jueshi Qian , Yun Bai","doi":"10.1016/j.cemconres.2025.108085","DOIUrl":"10.1016/j.cemconres.2025.108085","url":null,"abstract":"<div><div>The hydration inertness of ternesite (C<sub>5</sub>S<sub>2</sub>Š) is the primary barrier to the promotion of Ternesite-Ye'elimite Cement (TYC). This study investigated the potential of iron-doped calcium aluminates to activate the hydration of TYC systems, with particular focus on their roles in enhancing the reactivity of C<sub>5</sub>S<sub>2</sub>Š. Three types of calcium aluminates, viz. orthorhombic ye'elimite (C<sub>4</sub>A<sub>3</sub>Š), iron-doped cubic ye'elimite (C<sub>4</sub>(A,F)<sub>3</sub>Š) and ferrite (C<sub>4</sub>AF), as well as C<sub>5</sub>S<sub>2</sub>Š were synthesized in the laboratory. These four minerals, and three blends formulated by mixing each calcium aluminate with C<sub>5</sub>S<sub>2</sub>Š, were mixed with water to obtain a total of seven paste mixtures. Their hydration processes were examined using ICC, XRD, FT-IR, TG, and pore solution chemistry analysis to elucidate the influence of iron-doped calcium aluminates (C<sub>4</sub>(A,F)<sub>3</sub>Š and C<sub>4</sub>AF) on the hydration reactivity of C<sub>5</sub>S<sub>2</sub>Š and the corresponding mechanisms. Results show that C<sub>4</sub>(A,F)<sub>3</sub>Š significantly enhanced the hydration reactivity of C<sub>5</sub>S<sub>2</sub>Š by providing reactive amorphous (A,F)H<sub>3</sub> to consume gypsum from the hydration of C<sub>5</sub>S<sub>2</sub>Š. Evidently, iron doping exhibited a gypsum-like acceleration effect on the hydration of C<sub>5</sub>S<sub>2</sub>Š + C<sub>4</sub>(A,F)<sub>3</sub>Š system, albeit through a distinct chemical pathway. However, C<sub>4</sub>AF demonstrated quite limited effect on the C<sub>5</sub>S<sub>2</sub>Š + C<sub>4</sub>AF system, due to the gradual formation of a gel layer on the C<sub>4</sub>AF surface that restricted further hydration.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"200 ","pages":"Article 108085"},"PeriodicalIF":13.1,"publicationDate":"2025-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145447421","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}
Pub Date : 2025-11-03DOI: 10.1016/j.cemconres.2025.108072
Guangqi Xiong , Zheng Fang , Yuanliang Ren , Xiaolong Jia , Hongkuang Luo , Jiaxin Yang , Bo Ran , Shuai Zhou , Chong Wang
To address the limitations of conventional vibration in removing microbubbles from cement paste, this study introduces power ultrasound as a novel defoaming technology and investigates its effectiveness and mechanism. Experiments conducted at a water-to-cement ratio of 0.50, with or without air-entraining agents, and demonstrated that ultrasound treatment effectively eliminated microbubbles, as confirmed by 1H NMR and FBRM analyses. Compared to controls, treated batches exhibited increases in compressive strength of 17.1 % and 7.3 % at 3 days, and 6.8 % and 3.8 % at 28 days. Modeling indicates that bubbles move towards the pressure node once ultrasound is applied, and whether bubble coalescence occurs is primarily governed by the secondary Bjerknes force. Coalesced bubbles will then rise due to increased buoyancy. These findings highlight the significant potential of power ultrasound as an innovative and efficient defoaming technology for cement-based materials, offering improved microstructure and mechanical performance.
{"title":"A novel defoaming technology for cement paste by using power ultrasound treatment","authors":"Guangqi Xiong , Zheng Fang , Yuanliang Ren , Xiaolong Jia , Hongkuang Luo , Jiaxin Yang , Bo Ran , Shuai Zhou , Chong Wang","doi":"10.1016/j.cemconres.2025.108072","DOIUrl":"10.1016/j.cemconres.2025.108072","url":null,"abstract":"<div><div>To address the limitations of conventional vibration in removing microbubbles from cement paste, this study introduces power ultrasound as a novel defoaming technology and investigates its effectiveness and mechanism. Experiments conducted at a water-to-cement ratio of 0.50, with or without air-entraining agents, and demonstrated that ultrasound treatment effectively eliminated microbubbles, as confirmed by <sup>1</sup>H NMR and FBRM analyses. Compared to controls, treated batches exhibited increases in compressive strength of 17.1 % and 7.3 % at 3 days, and 6.8 % and 3.8 % at 28 days. Modeling indicates that bubbles move towards the pressure node once ultrasound is applied, and whether bubble coalescence occurs is primarily governed by the secondary Bjerknes force. Coalesced bubbles will then rise due to increased buoyancy. These findings highlight the significant potential of power ultrasound as an innovative and efficient defoaming technology for cement-based materials, offering improved microstructure and mechanical performance.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"200 ","pages":"Article 108072"},"PeriodicalIF":13.1,"publicationDate":"2025-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145434840","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":"Dynamic dissection of a sustainable cement alternative: A multiscale exploration of alkali-activated slag dissolution mechanisms","authors":"Jiazhi Huang , Baomin Wang","doi":"10.1016/j.cemconres.2025.108074","DOIUrl":"10.1016/j.cemconres.2025.108074","url":null,"abstract":"<div><div>The cement industry, contributing 8 % of global CO₂ emissions primarily through Ordinary Portland Cement (OPC) production (∼0.8–1.0 t CO₂/t), urgently requires low-carbon alternatives. This study elucidates atomic-scale dissolution mechanisms in alkali-activated ground granulated blast furnace slag (AAS) via integrated experimental-computational analysis. First-principles simulations of 412-atom GGBS models reveal Ca<sup>2+</sup>/Mg<sup>2+</sup> leaching initiates through non-bridging oxygen bond cleavage (ICOHP = -0.18–0.58 eV), while Al<sup>3+</sup>/Si<sup>4+</sup> release follows oligomer-mediated pathways. Quantum mechanics/molecular mechanics (QM/MM) calculations quantify bond-breaking energy barriers (Al-O-Al: 5.26 < Si-O-Al: 15.51 < Si-O-Si: 38.93 kcal/mol), governed by frontier orbital energy gaps (ΔE = 1.53–2.03 eV). Reactive molecular dynamics (MD) simulations identify three dissolution stages: Na<sup>+</sup>-assisted ion leaching (0–1 ns, D = 3.40 × 10<sup>−7</sup> m<sup>2</sup>/s), Al-O/Si-O network depolymerization (1–7 ns), and Ca-mediated calcium aluminosilicate hydrate (C-A-S-H) nucleation (7–30 ns). By modulating electronic structures to target these mechanisms, we achieve a 63 % carbon reduction compared to OPC. These findings establish design principles for next-generation GGBS-based cementitious materials, enabling scalable, low-carbon construction solutions with performance parity to conventional cement.</div><div><strong>Synopsis</strong></div><div>By transforming waste materials into valuable resources and reducing carbon emissions, we are paving the way for a more sustainable future.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"200 ","pages":"Article 108074"},"PeriodicalIF":13.1,"publicationDate":"2025-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145404945","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}
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