The influence of sodium hydroxide and citric acid on the hydration of a calcium aluminate cement – calcite mixture was investigated. Both the effect of the two additives individually and in combination were analysed. Sodium hydroxide accelerates the reaction, leads to dominant monocarbonate formation and higher inner strength. However, the workability is reduced. Citric acid retards the reaction, lowers the inner strength but has a positive influence on the workability. Furthermore, the main reaction with citric acid only begins when the concentration of citric acid in the pore solution drops below 125–115 mmol/l. In combination of both additives, NaOH improves the inner strength, whereas higher doses of citric acid improve the workability, whereby the dominant hydrate phase composition changes from monocarbonate to CAH10. In addition, it was observed that a higher degree of hydration within the first 24 h is associated with increased inner strength after 28 d.
{"title":"Optimization of hydration kinetics, phase development and mechanical properties of CAC in mix with calcite by addition of sodium hydroxide and citric acid","authors":"Pauline Rost , Christiane Rößler , Jürgen Neubauer , Friedlinde Goetz-Neunhoeffer","doi":"10.1016/j.cemconres.2025.108045","DOIUrl":"10.1016/j.cemconres.2025.108045","url":null,"abstract":"<div><div>The influence of sodium hydroxide and citric acid on the hydration of a calcium aluminate cement – calcite mixture was investigated. Both the effect of the two additives individually and in combination were analysed. Sodium hydroxide accelerates the reaction, leads to dominant monocarbonate formation and higher inner strength. However, the workability is reduced. Citric acid retards the reaction, lowers the inner strength but has a positive influence on the workability. Furthermore, the main reaction with citric acid only begins when the concentration of citric acid in the pore solution drops below 125–115 mmol/l. In combination of both additives, NaOH improves the inner strength, whereas higher doses of citric acid improve the workability, whereby the dominant hydrate phase composition changes from monocarbonate to CAH<sub>10</sub>. In addition, it was observed that a higher degree of hydration within the first 24 h is associated with increased inner strength after 28 d.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"199 ","pages":"Article 108045"},"PeriodicalIF":13.1,"publicationDate":"2025-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145089157","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 : 2025-09-19DOI: 10.1016/j.cemconres.2025.108040
Raphael Kuhn , Pietro Lura , Daniel Rentsch , Guillaume Habert , Ellina Bernard
Clay-based, low-CO₂ cement-stabilized materials offer a sustainable alternative to conventional building materials. This study examines the impact of various admixtures (Na-hexametaphosphate, Na‑carbonate, Na-silicate, Na-citrate, and Na-oxalate) on the rheological behavior of poured systems containing a MgO-metakaolin cement as stabilizer. The yield stress reduction follows the order Na-hexametaphosphate > Na-silicate > Na-citrate > Na-oxalate ≥ Na‑carbonate > no admixture. The zeta potential data with the solution analysis of the suspensions show that the adsorption of admixtures and/or a change in pH leads to a more negative surface, enhancing dispersion through electrostatic repulsion. Silicate and phosphate are not found in the suspension, 29Si ssNMR indicates that silicate precipitates and polymerizes most likely as M-S-H. The phosphates are most likely adsorbed onto particles with opening of the phosphate rings observed by 31P NMR. The anionic charge density of adsorbed polyphosphates was calculated and linked to the decreased colloid sizes observed with increasing Na-hexametaphosphate concentration.
{"title":"Dispersant mechanisms in clays stabilized with MgO-based cement","authors":"Raphael Kuhn , Pietro Lura , Daniel Rentsch , Guillaume Habert , Ellina Bernard","doi":"10.1016/j.cemconres.2025.108040","DOIUrl":"10.1016/j.cemconres.2025.108040","url":null,"abstract":"<div><div>Clay-based, low-CO₂ cement-stabilized materials offer a sustainable alternative to conventional building materials. This study examines the impact of various admixtures (Na-hexametaphosphate, Na‑carbonate, Na-silicate, Na-citrate, and Na-oxalate) on the rheological behavior of poured systems containing a MgO-metakaolin cement as stabilizer. The yield stress reduction follows the order Na-hexametaphosphate > Na-silicate > Na-citrate > Na-oxalate ≥ Na‑carbonate > no admixture. The zeta potential data with the solution analysis of the suspensions show that the adsorption of admixtures and/or a change in pH leads to a more negative surface, enhancing dispersion through electrostatic repulsion. Silicate and phosphate are not found in the suspension, <sup>29</sup>Si ssNMR indicates that silicate precipitates and polymerizes most likely as M-S-H. The phosphates are most likely adsorbed onto particles with opening of the phosphate rings observed by <sup>31</sup>P NMR. The anionic charge density of adsorbed polyphosphates was calculated and linked to the decreased colloid sizes observed with increasing Na-hexametaphosphate concentration.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"199 ","pages":"Article 108040"},"PeriodicalIF":13.1,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145089149","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 : 2025-09-19DOI: 10.1016/j.cemconres.2025.108037
Yuto Kanda , Ryo Kurihara , Ippei Maruyama
This study investigated the influence of curing temperature on the drying shrinkage behavior of cement paste by analyzing calcium silicate hydrate (C-S-H) microstructural changes. Ordinary Portland cement specimens were cured at 20, 60, and 80 °C and exposed to varying relative humidity conditions (11–95% RH). The microstructural evolution of C-S-H was quantitatively assessed using 1H NMR relaxometry and X-ray diffraction/Rietveld analysis.
Through evaluation of C-S-H density and specific surface area, we established that the densification mechanism induced by high-temperature curing mirrors the C-S-H stacking process during drying. This was supported by a consistent linear correlation between specific surface area and bulk density across all curing temperatures, indicating that high-temperature-cured specimens had already undergone partial shrinkage during curing. These findings provide a mechanistic explanation for the reduced drying shrinkage susceptibility of cement-based materials cured at elevated temperatures.
{"title":"Reduction of drying shrinkage via C-S-H densification: The role of early-age thermal history","authors":"Yuto Kanda , Ryo Kurihara , Ippei Maruyama","doi":"10.1016/j.cemconres.2025.108037","DOIUrl":"10.1016/j.cemconres.2025.108037","url":null,"abstract":"<div><div>This study investigated the influence of curing temperature on the drying shrinkage behavior of cement paste by analyzing calcium silicate hydrate (C-S-H) microstructural changes. Ordinary Portland cement specimens were cured at 20, 60, and 80 °C and exposed to varying relative humidity conditions (11–95% RH). The microstructural evolution of C-S-H was quantitatively assessed using <sup>1</sup>H NMR relaxometry and X-ray diffraction/Rietveld analysis.</div><div>Through evaluation of C-S-H density and specific surface area, we established that the densification mechanism induced by high-temperature curing mirrors the C-S-H stacking process during drying. This was supported by a consistent linear correlation between specific surface area and bulk density across all curing temperatures, indicating that high-temperature-cured specimens had already undergone partial shrinkage during curing. These findings provide a mechanistic explanation for the reduced drying shrinkage susceptibility of cement-based materials cured at elevated temperatures.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"199 ","pages":"Article 108037"},"PeriodicalIF":13.1,"publicationDate":"2025-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145084034","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 : 2025-09-17DOI: 10.1016/j.cemconres.2025.108044
Yu Zhang , Cheng Li , Shuangshuang Wang , Jing Zhong
The size effects of nanomaterials play a critical role in their reinforcement efficiency for polymer and metal nanocomposites, yet it has not been thoroughly demonstrated in cementitious matrices. This study systematically investigates the size effects of graphene oxide (GO) on cement hydration, microstructure, strength, and creep resistance. Compared to small-sized GO, large-sized GO (LGO) significantly enhances C-S-H packing density, hydration degree, and mechanical performance while reducing creep. These improvements stem from LGO's stronger templating effect and larger lateral size, which promote C-S-H nucleation and interparticle bonding, thus limiting C-S-H redistribution under load. Importantly, we reveal that GO enhances creep resistance not only by densifying C-S-H but also by modulating interfacial bonding in a size-dependent manner—a mechanism previously overlooked. These findings underscore the critical role of nanomaterial size effects in regulating stress transfer and microstructural evolution in cementitious systems, offering a new pathway for designing high-performance cement-based materials.
{"title":"Size effects of graphene oxide nanosheets on the mechanical property of cement pastes: Packing of C-S-H nanoparticles and mechanism","authors":"Yu Zhang , Cheng Li , Shuangshuang Wang , Jing Zhong","doi":"10.1016/j.cemconres.2025.108044","DOIUrl":"10.1016/j.cemconres.2025.108044","url":null,"abstract":"<div><div>The size effects of nanomaterials play a critical role in their reinforcement efficiency for polymer and metal nanocomposites, yet it has not been thoroughly demonstrated in cementitious matrices. This study systematically investigates the size effects of graphene oxide (GO) on cement hydration, microstructure, strength, and creep resistance. Compared to small-sized GO, large-sized GO (LGO) significantly enhances C-S-H packing density, hydration degree, and mechanical performance while reducing creep. These improvements stem from LGO's stronger templating effect and larger lateral size, which promote C-S-H nucleation and interparticle bonding, thus limiting C-S-H redistribution under load. Importantly, we reveal that GO enhances creep resistance not only by densifying C-S-H but also by modulating interfacial bonding in a size-dependent manner—a mechanism previously overlooked. These findings underscore the critical role of nanomaterial size effects in regulating stress transfer and microstructural evolution in cementitious systems, offering a new pathway for designing high-performance cement-based materials.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"199 ","pages":"Article 108044"},"PeriodicalIF":13.1,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145078368","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 : 2025-09-16DOI: 10.1016/j.cemconres.2025.108042
Fangmin Shen , Guojian Liu , Yunsheng Zhang , Cheng Liu
Sulfate attack can impair the chloride-binding capacity of Friedel's salt (FS) in cementitious materials by inducing the release of its bound chloride ions (Cl−). However, the atomic-level understanding of this reaction remains unclear. In this study, ab initio molecular dynamics (AIMD) is employed to elucidate the molecular-scale exchange kinetics of SO₄2−/Cl− at the FS/sulfate solution interface. The results demonstrate that SO₄2− weakens both the electrostatic binding of Cl− to the [Ca₂Al(OH)₆]+ layer and its hydrogen bonding with water in the [Cl·2H₂O]− layer through charge redistribution effect, thereby facilitating Cl− release and subsequent SO₄2− substitution. Furthermore, the dynamic reconstruction of hydrogen bond (H-bond) network within the FS anion-binding layer is a critical mechanism for interfacial restabilization after anion exchange. First-principles calculations confirm the significant thermodynamic spontaneity of the SO₄2−/Cl− exchange, highlighting both the ionic competitive advantage and binding stability of SO₄2−.
{"title":"Molecular insights into sulfate-induced chloride release from Friedel's salt","authors":"Fangmin Shen , Guojian Liu , Yunsheng Zhang , Cheng Liu","doi":"10.1016/j.cemconres.2025.108042","DOIUrl":"10.1016/j.cemconres.2025.108042","url":null,"abstract":"<div><div>Sulfate attack can impair the chloride-binding capacity of Friedel's salt (FS) in cementitious materials by inducing the release of its bound chloride ions (Cl<sup>−</sup>). However, the atomic-level understanding of this reaction remains unclear. In this study, ab initio molecular dynamics (AIMD) is employed to elucidate the molecular-scale exchange kinetics of SO₄<sup>2−</sup>/Cl<sup>−</sup> at the FS/sulfate solution interface. The results demonstrate that SO₄<sup>2−</sup> weakens both the electrostatic binding of Cl<sup>−</sup> to the [Ca₂Al(OH)₆]<sup>+</sup> layer and its hydrogen bonding with water in the [Cl·2H₂O]<sup>−</sup> layer through charge redistribution effect, thereby facilitating Cl<sup>−</sup> release and subsequent SO₄<sup>2−</sup> substitution. Furthermore, the dynamic reconstruction of hydrogen bond (H-bond) network within the FS anion-binding layer is a critical mechanism for interfacial restabilization after anion exchange. First-principles calculations confirm the significant thermodynamic spontaneity of the SO₄<sup>2−</sup>/Cl<sup>−</sup> exchange, highlighting both the ionic competitive advantage and binding stability of SO₄<sup>2−</sup>.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"199 ","pages":"Article 108042"},"PeriodicalIF":13.1,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145067799","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 : 2025-09-16DOI: 10.1016/j.cemconres.2025.108038
Julian L. Stapper , Quin R.S. Miller , Russell L. Detwiler , Mohammad Javad Abdolhosseini Qomi
Belite-rich cement is a promising low-carbon material, yet the limited hydraulic reactivity of its primary component, dicalcium silicate (-Ca2SiO4), still poses a challenge. This study introduces a new approach to examining the reaction kinetics and acceleration strategies for low-reactivity materials like -Ca2SiO4 using quasi in situ X-ray diffraction (XRD). By simultaneously analyzing pre-cured and fresh samples, the method reduces measurement time at the expense of lowering temporal resolution. Applying this technique to hydrating -Ca2SiO4 pastes from 21 to 80 °C provides insight into the underlying temperature-dependent dissolution process and its apparent activation energy (AAE). The estimated AAE of 49 ± 3 kJ/mol aligns with existing data and supports the view that the rate-limiting step of belite hydration may change based on the physical properties of the material. By offering phase-specific and time-resolved data, this method serves as a useful tool in devising science-informed strategies to accelerate hydration of belite-rich cements.
{"title":"Quantifying the effect of temperature on belite hydration kinetics through quasi in situ XRD","authors":"Julian L. Stapper , Quin R.S. Miller , Russell L. Detwiler , Mohammad Javad Abdolhosseini Qomi","doi":"10.1016/j.cemconres.2025.108038","DOIUrl":"10.1016/j.cemconres.2025.108038","url":null,"abstract":"<div><div>Belite-rich cement is a promising low-carbon material, yet the limited hydraulic reactivity of its primary component, dicalcium silicate (<span><math><mi>β</mi></math></span>-Ca<sub>2</sub>SiO<sub>4</sub>), still poses a challenge. This study introduces a new approach to examining the reaction kinetics and acceleration strategies for low-reactivity materials like <span><math><mi>β</mi></math></span>-Ca<sub>2</sub>SiO<sub>4</sub> using <em>quasi in situ</em> X-ray diffraction (XRD). By simultaneously analyzing pre-cured and fresh samples, the method reduces measurement time at the expense of lowering temporal resolution. Applying this technique to hydrating <span><math><mi>β</mi></math></span>-Ca<sub>2</sub>SiO<sub>4</sub> pastes from 21 to 80 °C provides insight into the underlying temperature-dependent dissolution process and its apparent activation energy (AAE). The estimated AAE of 49 ± 3 kJ/mol aligns with existing data and supports the view that the rate-limiting step of belite hydration may change based on the physical properties of the material. By offering phase-specific and time-resolved data, this method serves as a useful tool in devising science-informed strategies to accelerate hydration of belite-rich cements.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"199 ","pages":"Article 108038"},"PeriodicalIF":13.1,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145072128","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 : 2025-09-15DOI: 10.1016/j.cemconres.2025.108041
Xingdong Lv , Zhuofan Gao , Lu Yang , Fazhou Wang
This paper investigated the inhibition effects and mechanisms of organic phosphonic acids (OPAs) with distinct functional groups on triclinic tricalcium silicate (C3S) clinker hydration. In particular, the effects of three representative OPAs, namely ATMP, HEDP, and PBTC on adsorption/complexation behavior, hydration products, and microstructure characteristics of C3S clinker were studied. OPAs retardation of the C3S clinker hydration was governed by synergistic interactions of electrostatic adsorption, and cationic complexation, potentially involving intermolecular self-polycondensation. ATMP primarily relied on Ca2+ complexation through its [–C-PO(OH)2] groups, forming low-solubility precipitates that inhibited hydration. HEDP combined strong complexation with intermolecular self-polycondensation, driven by its [–C–PO(OH)2] and (–OH) groups, generating dense three-dimensional polymers that enhanced steric hindrance, while PBTC operated through surface adsorption and self-polycondensation. The revealed retardation efficiency hierarchy (HEDP > PBTC > ATMP) arose from functional group synergy: the maximal inhibition was provided by synergy of [–C–PO(OH)2] and (–OH) groups, a weaker one-by that of [–C–PO(OH)2] and (–COOH) groups, while isolated [–C–PO(OH)2] groups had the minimal retarding capacity.
{"title":"Retardation mechanisms and microstructure evolution of triclinic tricalcium silicate induced by three different organic phosphonic acids","authors":"Xingdong Lv , Zhuofan Gao , Lu Yang , Fazhou Wang","doi":"10.1016/j.cemconres.2025.108041","DOIUrl":"10.1016/j.cemconres.2025.108041","url":null,"abstract":"<div><div>This paper investigated the inhibition effects and mechanisms of organic phosphonic acids (OPAs) with distinct functional groups on triclinic tricalcium silicate (C<sub>3</sub>S) clinker hydration. In particular, the effects of three representative OPAs, namely ATMP, HEDP, and PBTC on adsorption/complexation behavior, hydration products, and microstructure characteristics of C<sub>3</sub>S clinker were studied. OPAs retardation of the C<sub>3</sub>S clinker hydration was governed by synergistic interactions of electrostatic adsorption, and cationic complexation, potentially involving intermolecular self-polycondensation. ATMP primarily relied on Ca<sup>2+</sup> complexation through its [–C-PO(OH)<sub>2</sub>] groups, forming low-solubility precipitates that inhibited hydration. HEDP combined strong complexation with intermolecular self-polycondensation, driven by its [–C–PO(OH)<sub>2</sub>] and (–OH) groups, generating dense three-dimensional polymers that enhanced steric hindrance, while PBTC operated through surface adsorption and self-polycondensation. The revealed retardation efficiency hierarchy (HEDP > PBTC > ATMP) arose from functional group synergy: the maximal inhibition was provided by synergy of [–C–PO(OH)<sub>2</sub>] and (–OH) groups, a weaker one-by that of [–C–PO(OH)<sub>2</sub>] and (–COOH) groups, while isolated [–C–PO(OH)<sub>2</sub>] groups had the minimal retarding capacity.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"199 ","pages":"Article 108041"},"PeriodicalIF":13.1,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145060019","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 : 2025-09-15DOI: 10.1016/j.cemconres.2025.108039
Zhenghao Li , Jing Yu , Jiajia Zhou , Christopher K.Y. Leung
The meso-level pore structure of Strain-Hardening/Engineered Cementitious Composites (SHCC/ECC) critically governs cracking strength distribution, and consequently the tensile performance. While pore distributions are typically attributed to matrix flowability, this relationship remains rarely quantified for SHCC. This study addresses this gap by linking material processing parameters, realistic pore structures, and tensile cracking behaviors of SHCC. Using X-ray computed tomography (X-CT), the 3D meso-level pore information (including porosity, size distribution, shape factors, and spatial distribution) of SHCC specimens was analyzed and correlated with matrix flowabilities. Mechanisms governing pore formation during mixing and casting were discussed. A statistically derived correlation between meso-level pore structures and matrix flowability was established and applied to predict cracking strength distributions. This correlation demonstrated improved agreement with experimental results over conventional methods. These findings advance the modeling and optimization of SHCC by providing a quantitative framework to account for matrix flowability effects.
{"title":"Meso-level pore structures of Strain-Hardening Cementitious Composites (SHCC): Correlation with matrix flowability and application in micromechanical modeling","authors":"Zhenghao Li , Jing Yu , Jiajia Zhou , Christopher K.Y. Leung","doi":"10.1016/j.cemconres.2025.108039","DOIUrl":"10.1016/j.cemconres.2025.108039","url":null,"abstract":"<div><div>The meso-level pore structure of Strain-Hardening/Engineered Cementitious Composites (SHCC/ECC) critically governs cracking strength distribution, and consequently the tensile performance. While pore distributions are typically attributed to matrix flowability, this relationship remains rarely quantified for SHCC. This study addresses this gap by linking material processing parameters, realistic pore structures, and tensile cracking behaviors of SHCC. Using X-ray computed tomography (X-CT), the 3D meso-level pore information (including porosity, size distribution, shape factors, and spatial distribution) of SHCC specimens was analyzed and correlated with matrix flowabilities. Mechanisms governing pore formation during mixing and casting were discussed. A statistically derived correlation between meso-level pore structures and matrix flowability was established and applied to predict cracking strength distributions. This correlation demonstrated improved agreement with experimental results over conventional methods. These findings advance the modeling and optimization of SHCC by providing a quantitative framework to account for matrix flowability effects.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"199 ","pages":"Article 108039"},"PeriodicalIF":13.1,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145067798","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 : 2025-09-14DOI: 10.1016/j.cemconres.2025.108030
Karam Mawas, Mehdi Maboudi, Markus Gerke
Given the substantial growth in the use of additive manufacturing in construction (AMC), it is necessary to ensure the quality of printed specimens, which can be much more complex than conventionally manufactured parts. This study examines the various aspects of geometry and surface quality control in 3D concrete printing (3DCP), with a particular emphasis on deposition-based methods, specifically extrusion and shotcrete 3D printing (SC3DP). A comprehensive overview of existing quality control (QC) methods and strategies is provided and preceded by an in-depth discussion. Four categories of data capture technologies are investigated and their advantages and limitations in the context of AMC are discussed. Additionally, the effects of environmental conditions and the properties of objects on data capture are also analyzed. The study extends to automated data capture planning methods for different sensors. Furthermore, various quality control strategies are explored across different stages of the fabrication cycle of the printed object including: (i) During printing, (ii) Layer-wise, (iii) Pre-assembly, and (iv) Assembly. In addition to reviewing the methods already applied in AMC, we also address various research gaps and future trends and highlight potential methodologies from adjacent domains that could be transferred to AMC.
{"title":"A review on geometry and surface inspection in 3D concrete printing","authors":"Karam Mawas, Mehdi Maboudi, Markus Gerke","doi":"10.1016/j.cemconres.2025.108030","DOIUrl":"10.1016/j.cemconres.2025.108030","url":null,"abstract":"<div><div>Given the substantial growth in the use of additive manufacturing in construction (AMC), it is necessary to ensure the quality of printed specimens, which can be much more complex than conventionally manufactured parts. This study examines the various aspects of geometry and surface quality control in 3D concrete printing (3DCP), with a particular emphasis on deposition-based methods, specifically extrusion and shotcrete 3D printing (SC3DP). A comprehensive overview of existing quality control (QC) methods and strategies is provided and preceded by an in-depth discussion. Four categories of data capture technologies are investigated and their advantages and limitations in the context of AMC are discussed. Additionally, the effects of environmental conditions and the properties of objects on data capture are also analyzed. The study extends to automated data capture planning methods for different sensors. Furthermore, various quality control strategies are explored across different stages of the fabrication cycle of the printed object including: (i) During printing, (ii) Layer-wise, (iii) Pre-assembly, and (iv) Assembly. In addition to reviewing the methods already applied in AMC, we also address various research gaps and future trends and highlight potential methodologies from adjacent domains that could be transferred to AMC.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"199 ","pages":"Article 108030"},"PeriodicalIF":13.1,"publicationDate":"2025-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145057199","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 : 2025-09-12DOI: 10.1016/j.cemconres.2025.108034
Yanjie Tang , Katrin Schollbach , Zixing Liu , Sieger van der Laan , Wei Chen , H.J.H. Brouwers
This study investigates the hydration behavior of basic oxygen furnace (BOF) slag in phosphate solutions across different pH levels, focusing on hydration kinetics, microstructure, and strength development. Acidic phosphate solutions trigger rapid dissolution via acid-base reactions, resulting in lower heat release, while alkaline phosphates promote sustained dissolution-precipitation reactions, prolonging hydration and increasing cumulative heat. The buffering effect of H2PO4−/HPO42− prolongs induction periods and inhibits hydrogarnet and layered double hydroxides (LDHs) formation. At early stages, C2S hydration is more pronounced in acidic solutions, whereas higher pH enhances late-stage hydration of C2S, brownmillerite, and wuestite, forming C-S-H, hydrogarnet, and LDHs. Despite similar porosities (11.9–13.9 %), strengths vary from 37.7 to 66.9 MPa due to a higher proportion of capillary pores and a larger average pore size at a low pH (pH at 4.2). The findings support using phosphate-rich wastewater to activate BOF slag, reducing phosphate discharge while developing low-carbon, cement-free binders.
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