Pub Date : 2025-10-27DOI: 10.1016/j.cemconres.2025.108064
L.C. Queiroz , W.S. Barbosa , M.D.S. de Lima , I.N.L. Paes , A.P. Kirchheim , C.P. Bergmann
Doping during Portland cement clinker synthesis significantly influences the stabilization and reactivity of tricalcium silicate (C3S) polymorphs. Therefore, this study investigates the effect of MgO, ZnO, and TiO2 doping (at 0.5 and 1.0 wt%) on the structural and hydration behavior of C3S. Synthesis was performed at 1500 °C for six hours, followed by characterization using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET) surface area analysis, and isothermal calorimetry. To further assess the catalytic effects of dopant ions on C3S hydration, higher doping levels (4.0 and 8.0 wt%) were also evaluated. The results show that doping promotes stabilization of the T3, M1, and M3 C3S polymorphs. Among the dopants, MgO-enhanced phases exhibited higher intrinsic reactivity. However, despite this increased reactivity, hydration rates were reduced across all systems due to a dual effect: catalytic interactions with the hydration products and the formation of a physical barrier by excess dopant. These findings provide new insights into the design of doped clinker systems for tailored hydration performance.
{"title":"Effect of ionic doping on the structure and reactivity of Portland cement tricalcium silicate","authors":"L.C. Queiroz , W.S. Barbosa , M.D.S. de Lima , I.N.L. Paes , A.P. Kirchheim , C.P. Bergmann","doi":"10.1016/j.cemconres.2025.108064","DOIUrl":"10.1016/j.cemconres.2025.108064","url":null,"abstract":"<div><div>Doping during Portland cement clinker synthesis significantly influences the stabilization and reactivity of tricalcium silicate (C<sub>3</sub>S) polymorphs. Therefore, this study investigates the effect of MgO, ZnO, and TiO<sub>2</sub> doping (at 0.5 and 1.0 wt%) on the structural and hydration behavior of C<sub>3</sub>S. Synthesis was performed at 1500 °C for six hours, followed by characterization using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET) surface area analysis, and isothermal calorimetry. To further assess the catalytic effects of dopant ions on C<sub>3</sub>S hydration, higher doping levels (4.0 and 8.0 wt%) were also evaluated. The results show that doping promotes stabilization of the T3, M1, and M3 C<sub>3</sub>S polymorphs. Among the dopants, MgO-enhanced phases exhibited higher intrinsic reactivity. However, despite this increased reactivity, hydration rates were reduced across all systems due to a dual effect: catalytic interactions with the hydration products and the formation of a physical barrier by excess dopant. These findings provide new insights into the design of doped clinker systems for tailored hydration performance.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"200 ","pages":"Article 108064"},"PeriodicalIF":13.1,"publicationDate":"2025-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145383654","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 : 2025-10-25DOI: 10.1016/j.cemconres.2025.108070
Dong Xie, Jianming Gao, Cheng Liu
Limestone is widely used as a mineral admixture in cementitious systems, while the sources of cohesion within the limestone particle network remain unclear, especially in the early hydration stages where significant interactions between particle networks and hydration bonds have not yet developed. In this study, the mixed solutions containing calcium ions (Ca2+), sulfate ions (SO42−), and polycarboxylate ethers (PCE) are used to simulate the complex cementitious environment, and electrokinetic measurements and rheology are conducted to investigate the adsorption mechanisms and interparticle forces. The results indicate that Ca2+ ions, strongly adsorbed onto the surface of limestone particles, acting as potential determining ions, are involved in the reconstruction of cohesive networks, conforming to the classic DLVO theory. In SO42−-regulated suspensions with variable ionic strength, the yield stress exhibits a strong linear correlation with the squared zeta potential. The spatial hindrance and electrostatic repulsion generated by PCE adsorption are weakened due to the competitive adsorption of SO42−, while positive charge sites on particle surface can be effectively supplemented by Ca2+, which mediate the adsorption of PCE and significantly reduce competition with SO42−.
{"title":"Cohesion forces of limestone suspensions: Effects of adsorbed calcium ions, sulfate ions and polycarboxylate ethers","authors":"Dong Xie, Jianming Gao, Cheng Liu","doi":"10.1016/j.cemconres.2025.108070","DOIUrl":"10.1016/j.cemconres.2025.108070","url":null,"abstract":"<div><div>Limestone is widely used as a mineral admixture in cementitious systems, while the sources of cohesion within the limestone particle network remain unclear, especially in the early hydration stages where significant interactions between particle networks and hydration bonds have not yet developed. In this study, the mixed solutions containing calcium ions (Ca<sup>2+</sup>), sulfate ions (SO<sub>4</sub><sup>2−</sup>), and polycarboxylate ethers (PCE) are used to simulate the complex cementitious environment, and electrokinetic measurements and rheology are conducted to investigate the adsorption mechanisms and interparticle forces. The results indicate that Ca<sup>2+</sup> ions, strongly adsorbed onto the surface of limestone particles, acting as potential determining ions, are involved in the reconstruction of cohesive networks, conforming to the classic DLVO theory. In SO<sub>4</sub><sup>2−</sup>-regulated suspensions with variable ionic strength, the yield stress exhibits a strong linear correlation with the squared zeta potential. The spatial hindrance and electrostatic repulsion generated by PCE adsorption are weakened due to the competitive adsorption of SO<sub>4</sub><sup>2−</sup>, while positive charge sites on particle surface can be effectively supplemented by Ca<sup>2+</sup>, which mediate the adsorption of PCE and significantly reduce competition with SO<sub>4</sub><sup>2−</sup>.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"200 ","pages":"Article 108070"},"PeriodicalIF":13.1,"publicationDate":"2025-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145360492","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 : 2025-10-24DOI: 10.1016/j.cemconres.2025.108069
Oluwadamilare Charles Adesina , Sahil Surehali , Avinaya Tripathi , Kayla Lauren Lee , Bryan K. Aylas-Paredes , Aditya Kumar , Narayanan Neithalath
Limestone-calcined clay cements () reduce the environmental impact of cement production and accelerate the industry transition toward carbon neutrality. While conventional with 50% clinker replacement (-50) demonstrate long-term performance comparable to ordinary Portland cement (OPC) in concrete, early-age performance is generally compromised. This study explores for the first time, joint thermal treatment—that is, co-calcination—of limestone (LS) and bulk kaolinitic clay in mass ratios of 1:1 to 1:4 under a calcination regime specifically designed to ensure activation of the clay mineral. The co-calcination converts a small fraction of LS to metastable CaO, thus providing an additional reactive calcium source during hydration. Microstructural, kinetic, and thermodynamic studies on systems with 50% clinker replacement are used to quantify enhanced early-stage in situ formation of portlandite, which promotes the precipitation of and carboaluminate hydrates, that refine the pore structure and improve early-age strength—even in systems with low calcined clay content. A performance-efficiency index is used to indicate the improved mechanical and environmental performance of co-calcined blends as compared to traditional . The approach offers a potential pathway to achieving higher clinker substitution levels.
{"title":"Co-calcination of limestone and clay enhances the performance of limestone calcined clay cement (LC3)","authors":"Oluwadamilare Charles Adesina , Sahil Surehali , Avinaya Tripathi , Kayla Lauren Lee , Bryan K. Aylas-Paredes , Aditya Kumar , Narayanan Neithalath","doi":"10.1016/j.cemconres.2025.108069","DOIUrl":"10.1016/j.cemconres.2025.108069","url":null,"abstract":"<div><div>Limestone-calcined clay cements (<span><math><msup><mi>LC</mi><mn>3</mn></msup></math></span>) reduce the environmental impact of cement production and accelerate the industry transition toward carbon neutrality. While conventional <span><math><msup><mi>LC</mi><mn>3</mn></msup></math></span> with 50% clinker replacement (<span><math><msup><mi>LC</mi><mn>3</mn></msup></math></span>-50) demonstrate long-term performance comparable to ordinary Portland cement (OPC) in concrete, early-age performance is generally compromised. This study explores for the first time, joint thermal treatment—that is, co-calcination—of limestone (LS) and bulk kaolinitic clay in mass ratios of 1:1 to 1:4 under a calcination regime specifically designed to ensure activation of the clay mineral. The co-calcination converts a small fraction of LS to metastable CaO, thus providing an additional reactive calcium source during hydration. Microstructural, kinetic, and thermodynamic studies on systems with 50% clinker replacement are used to quantify enhanced early-stage in situ formation of portlandite, which promotes the precipitation of <span><math><mi>C</mi><mo>−</mo><mfenced><mi>A</mi></mfenced><mo>−</mo><mi>S</mi><mo>−</mo><mi>H</mi></math></span> and carboaluminate hydrates, that refine the pore structure and improve early-age strength—even in systems with low calcined clay content. A performance-efficiency index is used to indicate the improved mechanical and environmental performance of co-calcined blends as compared to traditional <span><math><msup><mi>LC</mi><mn>3</mn></msup></math></span>. The approach offers a potential pathway to achieving higher clinker substitution levels.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"200 ","pages":"Article 108069"},"PeriodicalIF":13.1,"publicationDate":"2025-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145340212","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 : 2025-10-23DOI: 10.1016/j.cemconres.2025.108066
Luis Schnürer, Henrik Eickhoff, Harald Hilbig, Alisa Machner
Since the reactivity of SCMs is affected by different specific properties, it is crucial to understand their impact. This study, therefore, focuses on how the Al content and Ca/Si ratio affect the structure and reactivity of calcium aluminosilicate glasses. The glasses were synthesized amorphous in 2 series with Al contents ranging from 5 to 40 wt% (Ca/Si mass ratio = 1:1) and Ca/Si ratios ranging from 0.21 to 1.00 (Al2O3 content = 15 wt%). Structural analysis by FTIR, 27Al and 29Si MAS NMR, and theoretical NBO/T calculations showed an increasing degree of polymerization with increasing Al content or decreasing Ca/Si ratio. The reactivity, examined by the R3 test and in cement pastes, was less affected by the degree of polymerization but more by the Al content. These findings provide insights into the dependence of structure and composition on the reactivity of model SCMs that may help in the search for new SCM sources in the future.
{"title":"Effect of the Al content and the Ca/Si ratio on the structure and reactivity of calcium aluminosilicate glasses used as model SCMs","authors":"Luis Schnürer, Henrik Eickhoff, Harald Hilbig, Alisa Machner","doi":"10.1016/j.cemconres.2025.108066","DOIUrl":"10.1016/j.cemconres.2025.108066","url":null,"abstract":"<div><div>Since the reactivity of SCMs is affected by different specific properties, it is crucial to understand their impact. This study, therefore, focuses on how the Al content and Ca/Si ratio affect the structure and reactivity of calcium aluminosilicate glasses. The glasses were synthesized amorphous in 2 series with Al contents ranging from 5 to 40 wt% (Ca/Si mass ratio = 1:1) and Ca/Si ratios ranging from 0.21 to 1.00 (Al<sub>2</sub>O<sub>3</sub> content = 15 wt%). Structural analysis by FTIR, <sup>27</sup>Al and <sup>29</sup>Si MAS NMR, and theoretical NBO/T calculations showed an increasing degree of polymerization with increasing Al content or decreasing Ca/Si ratio. The reactivity, examined by the R<sup>3</sup> test and in cement pastes, was less affected by the degree of polymerization but more by the Al content. These findings provide insights into the dependence of structure and composition on the reactivity of model SCMs that may help in the search for new SCM sources in the future.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"199 ","pages":"Article 108066"},"PeriodicalIF":13.1,"publicationDate":"2025-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145358518","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 : 2025-10-22DOI: 10.1016/j.cemconres.2025.108067
Eduardo Duque-Redondo , Felipe Basquiroto de Souza , Guoqing Geng , Hegoi Manzano
The use of atomic-scale modelling in the study of cement-related materials has grown steadily. However, the complexity of the systems under investigation and disparities in length and time scales between simulations and real-world processes, has hindered a clear demonstration of simulation-driven design of cement properties. The presence of multiple components, with intricate atomic and nanoscale structures and high degrees of amorphicity, makes the construction of realistic atomic-scale models the major challenge. This paper presents a critical review of state-of-the-art models of non-crystalline cementitious materials. Special attention is given to calcium silicate hydrate (C–S–H), where recent advances in bulk and interface models, disorder quantification, and novel formation mechanisms are assessed. The review also covers other key phases, including amorphous aluminosilicates, amorphous carbonates, and magnesium silicate hydrates (M–S–H). By outlining current methodologies and limitations, this work aims to inspire new approaches and tools for advancing predictive modelling of increasingly complex cementitious systems.
{"title":"A critical review and perspectives on atomistic models of non-crystalline cementitious materials","authors":"Eduardo Duque-Redondo , Felipe Basquiroto de Souza , Guoqing Geng , Hegoi Manzano","doi":"10.1016/j.cemconres.2025.108067","DOIUrl":"10.1016/j.cemconres.2025.108067","url":null,"abstract":"<div><div>The use of atomic-scale modelling in the study of cement-related materials has grown steadily. However, the complexity of the systems under investigation and disparities in length and time scales between simulations and real-world processes, has hindered a clear demonstration of simulation-driven design of cement properties. The presence of multiple components, with intricate atomic and nanoscale structures and high degrees of amorphicity, makes the construction of realistic atomic-scale models the major challenge. This paper presents a critical review of state-of-the-art models of non-crystalline cementitious materials. Special attention is given to calcium silicate hydrate (C–S–H), where recent advances in bulk and interface models, disorder quantification, and novel formation mechanisms are assessed. The review also covers other key phases, including amorphous aluminosilicates, amorphous carbonates, and magnesium silicate hydrates (M–S–H). By outlining current methodologies and limitations, this work aims to inspire new approaches and tools for advancing predictive modelling of increasingly complex cementitious systems.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"199 ","pages":"Article 108067"},"PeriodicalIF":13.1,"publicationDate":"2025-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145358520","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 : 2025-10-21DOI: 10.1016/j.cemconres.2025.108054
Anita Zhang , Claire E. White
Chemical degradation of cement-based materials is strongly influenced by the permeability and associated pore structure of the paste. In this work, the permeability of sodium silicate-activated metakaolin with a silicate modulus of 1.5 has been quantified using the beam bending technique and compared with pore size data obtained using nitrogen adsorption-desorption (NAD) and mercury intrusion porosimetry (MIP). Pastes with lower CO2 emissions have been evaluated, including the effects of reduced alkali concentrations (i.e., 2.5 versus 5.0 m Na2O activator) combined with addition of alkali earth oxide/hydroxides. While it is found that all pastes with reduced alkali concentrations exhibit larger average breakthrough pore sizes and higher permeability than the control system, both calcium hydroxide and magnesium oxide are effective at decreasing the average breakthrough pore size and permeability. On a molar basis calcium hydroxide is more effective than magnesium oxide at reducing permeability; however, more magnesium oxide can be added overall without a significant loss of workability, making it a more viable approach. Insights from X-ray diffraction (XRD) reveal that the observed physical effects can be attributed to the ability of calcium hydroxide and magnesium oxide to form gel hydrate phases with silicates from the activator and promote metakaolin dissolution.
水泥基材料的化学降解受到膏体渗透性和相关孔隙结构的强烈影响。本文采用光束弯曲技术对硅酸盐模量为1.5的硅酸钠活化偏高岭土的渗透率进行了量化，并与采用氮吸附解吸法（NAD）和压汞法（MIP）获得的孔径数据进行了比较。对二氧化碳排放量较低的浆料进行了评估，包括降低碱浓度（即2.5 m与5.0 m Na2O活化剂）与添加碱土氧化物/氢氧化物的效果。结果表明，碱浓度降低后膏体的平均突破孔径和渗透率均大于对照体系，而氢氧化钙和氧化镁均能有效降低平均突破孔径和渗透率。在摩尔基础上，氢氧化钙在降低渗透性方面比氧化镁更有效；然而，可以在整体上添加更多的氧化镁而不会显著损失可加工性，使其成为一种更可行的方法。x射线衍射（XRD）分析表明，观察到的物理效应可归因于氢氧化钙和氧化镁与活化剂中的硅酸盐形成凝胶水合物相的能力，并促进偏高岭土的溶解。
{"title":"Permeability of sodium silicate-activated metakaolin: Impact of reduced activator concentration and alkali earth oxide/hydroxide","authors":"Anita Zhang , Claire E. White","doi":"10.1016/j.cemconres.2025.108054","DOIUrl":"10.1016/j.cemconres.2025.108054","url":null,"abstract":"<div><div>Chemical degradation of cement-based materials is strongly influenced by the permeability and associated pore structure of the paste. In this work, the permeability of sodium silicate-activated metakaolin with a silicate modulus of 1.5 has been quantified using the beam bending technique and compared with pore size data obtained using nitrogen adsorption-desorption (NAD) and mercury intrusion porosimetry (MIP). Pastes with lower CO<sub>2</sub> emissions have been evaluated, including the effects of reduced alkali concentrations (i.e., 2.5 versus 5.0 <em>m</em> Na<sub>2</sub>O activator) combined with addition of alkali earth oxide/hydroxides. While it is found that all pastes with reduced alkali concentrations exhibit larger average breakthrough pore sizes and higher permeability than the control system, both calcium hydroxide and magnesium oxide are effective at decreasing the average breakthrough pore size and permeability. On a molar basis calcium hydroxide is more effective than magnesium oxide at reducing permeability; however, more magnesium oxide can be added overall without a significant loss of workability, making it a more viable approach. Insights from X-ray diffraction (XRD) reveal that the observed physical effects can be attributed to the ability of calcium hydroxide and magnesium oxide to form gel hydrate phases with silicates from the activator and promote metakaolin dissolution.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"199 ","pages":"Article 108054"},"PeriodicalIF":13.1,"publicationDate":"2025-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145358519","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 : 2025-10-17DOI: 10.1016/j.cemconres.2025.108062
Xiang Xi , Zijie Zhao , Wenkui Dong , Jingming Cai , Yue Gu , Wenyi Zhang , Hongqiang Chu , Qianping Ran
This study investigates the factors influencing the electrical, dielectric, and electromagnetic properties of fly ash-based geopolymer pastes (GP) by comparing their electrical resistivity, relative permittivity, and electromagnetic interference (EMI) shielding effectiveness under varying design parameters, including the water-to-binder (W/B) ratio, alkali modulus, and slag content. The results reveal that both DC and AC resistivity increase with a lower W/B ratio, higher alkali modulus, and greater slag content. Conversely, relative permittivity increases with a higher W/B ratio, lower alkali modulus, and greater slag content. These electrical and dielectric properties are interrelated, as they both depend on microstructural characteristics and their effects on charge movement and concentration. The predominant EMI shielding mechanism, whether reflection or absorption, is determined by the design parameters. Specifically, a higher W/B ratio correlates with greater reflection loss due to high relative permittivity and conductivity. A higher alkali modulus is associated with increased total shielding loss, also driven by high relative permittivity and conductivity. When slag content is increased, high resistivity combined with moderate relative permittivity leads to higher total shielding loss. The reflection of electromagnetic waves by GP is attributed to the impedance mismatch between the GP and air, while absorption results from conduction loss and polarization losses, including dipolar polarization, polarization relaxation, interfacial polarization, and molecular currents. This study provides valuable insights into the potential of geopolymers as functional materials.
{"title":"Factors that govern the electrical, dielectric, and electromagnetic properties of hardened fly ash-based geopolymer composites","authors":"Xiang Xi , Zijie Zhao , Wenkui Dong , Jingming Cai , Yue Gu , Wenyi Zhang , Hongqiang Chu , Qianping Ran","doi":"10.1016/j.cemconres.2025.108062","DOIUrl":"10.1016/j.cemconres.2025.108062","url":null,"abstract":"<div><div>This study investigates the factors influencing the electrical, dielectric, and electromagnetic properties of fly ash-based geopolymer pastes (GP) by comparing their electrical resistivity, relative permittivity, and electromagnetic interference (EMI) shielding effectiveness under varying design parameters, including the water-to-binder (W/B) ratio, alkali modulus, and slag content. The results reveal that both DC and AC resistivity increase with a lower W/B ratio, higher alkali modulus, and greater slag content. Conversely, relative permittivity increases with a higher W/B ratio, lower alkali modulus, and greater slag content. These electrical and dielectric properties are interrelated, as they both depend on microstructural characteristics and their effects on charge movement and concentration. The predominant EMI shielding mechanism, whether reflection or absorption, is determined by the design parameters. Specifically, a higher W/B ratio correlates with greater reflection loss due to high relative permittivity and conductivity. A higher alkali modulus is associated with increased total shielding loss, also driven by high relative permittivity and conductivity. When slag content is increased, high resistivity combined with moderate relative permittivity leads to higher total shielding loss. The reflection of electromagnetic waves by GP is attributed to the impedance mismatch between the GP and air, while absorption results from conduction loss and polarization losses, including dipolar polarization, polarization relaxation, interfacial polarization, and molecular currents. This study provides valuable insights into the potential of geopolymers as functional materials.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"199 ","pages":"Article 108062"},"PeriodicalIF":13.1,"publicationDate":"2025-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145314685","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 : 2025-10-16DOI: 10.1016/j.cemconres.2025.108063
Xiangdong Yan, Alessandro Fascetti
Air void analysis in hardened concrete typically requires the Linear Traverse Method (Procedure A) or the Modified Point-Count Method (Procedure B), as described in ASTM C457, to assess the content and distribution of entrapped and entrained air voids. These parameters are critical for assessing freeze–thaw resistance, workability, and mechanical properties. Conventional approaches rely on manual sampling and inspection by trained technicians, which are not only time-consuming and labor-intensive but also inherently subjective due to operator-dependent interpretations. This study proposes a novel framework integrating Photometric Stereo and Vision Transformer models to automate air void analysis with enhanced speed, accuracy, and generalizability. By leveraging a newly designed photometric stereo system and a computer vision-based image processing pipeline, the proposed method addresses key limitations in existing techniques, such as the inability to detect shallow or deep voids, incomplete boundary identification, and challenges in distinguishing air voids from aggregates. The framework seamlessly integrates image acquisition, recognition, extraction, and analysis, completing the entire process within approximately 10 min, excluding initial specimen preparation. When compared to current automated petrographic analysis methods, this approach achieves state-of-the-art precision, with mean accuracies of 97.970% for air void content and 97.176% for spacing factor, while eliminating the need for surface treatments or extensive model training. Furthermore, the study reports a comprehensive sensitivity analysis of parameter selection in Procedures A and B, offering deeper insights into ASTM C457 specifications. The proposed solution significantly reduces time and labor costs associated with air void analysis, enhances result reliability, and demonstrates potential for broader applications in micro-scale 3D surface reconstruction and property evaluation.
{"title":"A photometric stereo and Vision Transformer-based framework for automated air void analysis in hardened concrete","authors":"Xiangdong Yan, Alessandro Fascetti","doi":"10.1016/j.cemconres.2025.108063","DOIUrl":"10.1016/j.cemconres.2025.108063","url":null,"abstract":"<div><div>Air void analysis in hardened concrete typically requires the Linear Traverse Method (Procedure A) or the Modified Point-Count Method (Procedure B), as described in ASTM C457, to assess the content and distribution of entrapped and entrained air voids. These parameters are critical for assessing freeze–thaw resistance, workability, and mechanical properties. Conventional approaches rely on manual sampling and inspection by trained technicians, which are not only time-consuming and labor-intensive but also inherently subjective due to operator-dependent interpretations. This study proposes a novel framework integrating Photometric Stereo and Vision Transformer models to automate air void analysis with enhanced speed, accuracy, and generalizability. By leveraging a newly designed photometric stereo system and a computer vision-based image processing pipeline, the proposed method addresses key limitations in existing techniques, such as the inability to detect shallow or deep voids, incomplete boundary identification, and challenges in distinguishing air voids from aggregates. The framework seamlessly integrates image acquisition, recognition, extraction, and analysis, completing the entire process within approximately 10 min, excluding initial specimen preparation. When compared to current automated petrographic analysis methods, this approach achieves state-of-the-art precision, with mean accuracies of 97.970% for air void content and 97.176% for spacing factor, while eliminating the need for surface treatments or extensive model training. Furthermore, the study reports a comprehensive sensitivity analysis of parameter selection in Procedures A and B, offering deeper insights into ASTM C457 specifications. The proposed solution significantly reduces time and labor costs associated with air void analysis, enhances result reliability, and demonstrates potential for broader applications in micro-scale 3D surface reconstruction and property evaluation.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"199 ","pages":"Article 108063"},"PeriodicalIF":13.1,"publicationDate":"2025-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145295092","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 : 2025-10-11DOI: 10.1016/j.cemconres.2025.108059
Yifeng Ling , Guang Yin , Lijun Wang , Hui Jin , Bo Li , Weizhuo Shi , Shilang Xu
Superhydrophobic surfaces have attracted significant attention due to their ability to enhance the durability of concrete by preventing water and aggressive agent penetration. However, traditional superhydrophobic materials have limitations, being poorly durable and prone to wear. In this study, we propose a novel design for robust superhydrophobic cementitious composites: nano-CaCO₃ is grown ex-situ on fly ash particles to ensure the complete leaching of Ca2+ from carbide slag during carbonation, which also allows nano-CaCO₃ to be uniformly introduced into the composite through a carrier effect of carbonated fly ash. In addition, fluoroalkylsilane was incorporated into the carbon-sequestered composite to further reduce surface energy and achieve superhydrophobicity. The results demonstrate that the hydrophobicity of the composites is closely tied to the carbonation process, with a contact angle of 163.0° which signifies a superhydrophobic condition. This study provides valuable insights into the innovative design and production of carbon-sequestered, robust superhydrophobic cement-based materials.
{"title":"Robust superhydrophobic cementitious composites with ex-situ carbonation: Performance and mechanism","authors":"Yifeng Ling , Guang Yin , Lijun Wang , Hui Jin , Bo Li , Weizhuo Shi , Shilang Xu","doi":"10.1016/j.cemconres.2025.108059","DOIUrl":"10.1016/j.cemconres.2025.108059","url":null,"abstract":"<div><div>Superhydrophobic surfaces have attracted significant attention due to their ability to enhance the durability of concrete by preventing water and aggressive agent penetration. However, traditional superhydrophobic materials have limitations, being poorly durable and prone to wear. In this study, we propose a novel design for robust superhydrophobic cementitious composites: nano-CaCO₃ is grown ex-situ on fly ash particles to ensure the complete leaching of Ca<sup>2+</sup> from carbide slag during carbonation, which also allows nano-CaCO₃ to be uniformly introduced into the composite through a carrier effect of carbonated fly ash. In addition, fluoroalkylsilane was incorporated into the carbon-sequestered composite to further reduce surface energy and achieve superhydrophobicity. The results demonstrate that the hydrophobicity of the composites is closely tied to the carbonation process, with a contact angle of 163.0° which signifies a superhydrophobic condition. This study provides valuable insights into the innovative design and production of carbon-sequestered, robust superhydrophobic cement-based materials.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"199 ","pages":"Article 108059"},"PeriodicalIF":13.1,"publicationDate":"2025-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145260812","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 : 2025-10-11DOI: 10.1016/j.cemconres.2025.108056
Subhashree Panda , Luis Schnürer , Alisa Machner , Luis Ruiz Pestana , Prannoy Suraneni
CO2 mineralization has gained increasing attention as a strategy to reduce emissions from concrete production. This study investigates the carbonation potential of several calcium aluminosilicate (CAS) materials, model systems for understanding supplementary cementitious materials (SCMs). CAS materials were synthesized at temperatures ranging from 1000 °C to 1600 °C, producing structures ranging from partially crystalline to fully amorphous. X-ray diffraction and scanning electron microscopy were used to understand material physicochemical properties. Carbonation potential was assessed through CO2 uptake measurements using thermogravimetric analysis and Fourier-transform infrared spectroscopy, while SCM reactivity was evaluated via a modified R3 test. Results show that materials synthesized at 1000 °C and 1200 °C, containing unreacted oxides, portlandite, CA, and C2S, exhibited the highest CO2 uptake but the lowest reactivity as SCM. In contrast, fully amorphous glasses synthesized at 1600 °C demonstrated significantly higher SCM reactivity but minimal CO2 uptake. These findings highlight a fundamental trade-off between their reactivity and carbonation potential, governed by the degree of amorphization.
{"title":"CO2 uptake in calcium aluminosilicate materials","authors":"Subhashree Panda , Luis Schnürer , Alisa Machner , Luis Ruiz Pestana , Prannoy Suraneni","doi":"10.1016/j.cemconres.2025.108056","DOIUrl":"10.1016/j.cemconres.2025.108056","url":null,"abstract":"<div><div>CO<sub>2</sub> mineralization has gained increasing attention as a strategy to reduce emissions from concrete production. This study investigates the carbonation potential of several calcium aluminosilicate (CAS) materials, model systems for understanding supplementary cementitious materials (SCMs). CAS materials were synthesized at temperatures ranging from 1000 °C to 1600 °C, producing structures ranging from partially crystalline to fully amorphous. X-ray diffraction and scanning electron microscopy were used to understand material physicochemical properties. Carbonation potential was assessed through CO<sub>2</sub> uptake measurements using thermogravimetric analysis and Fourier-transform infrared spectroscopy, while SCM reactivity was evaluated via a modified R<sup>3</sup> test. Results show that materials synthesized at 1000 °C and 1200 °C, containing unreacted oxides, portlandite, CA, and C<sub>2</sub>S, exhibited the highest CO<sub>2</sub> uptake but the lowest reactivity as SCM. In contrast, fully amorphous glasses synthesized at 1600 °C demonstrated significantly higher SCM reactivity but minimal CO<sub>2</sub> uptake. These findings highlight a fundamental trade-off between their reactivity and carbonation potential, governed by the degree of amorphization.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"199 ","pages":"Article 108056"},"PeriodicalIF":13.1,"publicationDate":"2025-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145261121","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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