Cement and Concrete Research最新文献

{"title":"Effects of curing regimes and binder designs on steel slag-based carbonated aerated concrete (CAC): Reaching a balance between pre-hydration and carbonation","authors":"Rui Sun ,&nbsp;Peiliang Shen ,&nbsp;Xiao Zhang ,&nbsp;Qinglong Qin ,&nbsp;Yong Tao ,&nbsp;Dongmin Wang ,&nbsp;Ze Liu ,&nbsp;Chi-sun Poon","doi":"10.1016/j.cemconres.2025.107905","DOIUrl":"10.1016/j.cemconres.2025.107905","url":null,"abstract":"<div><div>Carbonated aerated concrete (CAC) is recognized as a low-energy alternative to conventional aerated concrete. In this study, the effects of curing methods and binder design on CAC performance, microstructure, and phase evolution are examined. A key contribution is the identification of the balance between pre-hydration and carbonation, a critical yet underexplored factor in strength development. It is demonstrated that insufficient pre-hydration retains excess moisture, hindering C₂S carbonation, while excessive pre-hydration restricts CO₂ diffusion. Two criteria are proposed for optimizing the pre-hydration: the reaction degree of C₂S reaching 40 % and the stabilization of the average pore size of the CAC matrix. Additionally, replacing 60 %–80 % of fly ash with steel slag in the binder mix has been shown to enhance carbonation efficiency and mechanical properties while maintaining a desirable dry density. These findings provide a practical framework for refining CAC mix design and curing strategies, facilitating broader application in sustainable construction.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"195 ","pages":"Article 107905"},"PeriodicalIF":10.9,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143869224","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":"Unravelling the role of iron oxidation states in alkali-activated slags: A multinuclear solid-state NMR study on polymerization and structural evolution","authors":"Ziyou Yu ,&nbsp;Alexios P. Douvalis ,&nbsp;Rodrigo de Oliveira-Silva ,&nbsp;Qifeng Shu ,&nbsp;Yiannis Pontikes ,&nbsp;Dimitrios Sakellariou","doi":"10.1016/j.cemconres.2025.107897","DOIUrl":"10.1016/j.cemconres.2025.107897","url":null,"abstract":"<div><div>Understanding the structure and polymerization behavior of Fe-bearing alkali-activated slags (AASs) is crucial for optimizing their macroscopic properties and expanding their applications in sustainable construction materials, radioactive waste storage, carbon sequestration, and other environmental technologies. This paper investigates the effect of iron oxidation state in precursor slags on the polymerization and microstructural evolution of synthesized AASs using advanced solid-state NMR with 1D MAS and 2D 3QMAS experiments. ⁵⁷Fe Mössbauer spectroscopy and Raman spectroscopy further provide insights into Fe coordination and phase composition. The synthesized slags were designed with controlled Fe content (&lt;10 wt%), ensuring sufficient NMR spectral resolution. The results show that after 7 days of curing, AASs synthesized from Fe²⁺-rich slag exhibits lower structure polymerization compared to those derived from the Fe³⁺-rich slags. After 1 year of storage, Fe²⁺-rich AAS undergoes further polymerization, leading to the formation of highly connected silicate structures. Based on the NMR analysis, we propose that Fe³⁺ is incorporated into the Al^VI site in hydrotalcite or as a charge balancing cation near the Al^IV site in the bridging positions, with only a minor fraction potentially in tetrahedral coordination. This study highlights the critical role of iron oxidation state in tuning the polymerization and structural evolution of AASs, providing a fundamental understanding that can guide the design of next-generation Fe-bearing alkali-activated materials.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"195 ","pages":"Article 107897"},"PeriodicalIF":10.9,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143863497","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":"Nanoscale measurement of adhesion forces and atomic-scale mechanisms at CSH/SiO2 and CSH/PVP-co-PAA interfaces","authors":"Gang Qiao ,&nbsp;Yuyang Zhao ,&nbsp;Pan Wang ,&nbsp;Dongshuai Hou ,&nbsp;Binmeng Chen","doi":"10.1016/j.cemconres.2025.107900","DOIUrl":"10.1016/j.cemconres.2025.107900","url":null,"abstract":"<div><div>Interface between calcium silicate hydrate (CSH) and polymers is crucial for the mechanical properties and durability. However, direct experimental determination of interfacial mechanics at nanoscale has not been reported. Herein, atomic force microscopy (AFM) with grafted Poly (1-vinylpyrrolidone-<em>co</em>-acrylic acid) (PVP-co-PAA) on AFM tips were utilized to measure interfacial properties between CSH and PVP-co-PAA under four C/S at nanoscale. The interfacial force curves were clearly presented for the first time. Results showed that compared to as-received tip, representing SiO₂, the adhesive force and energy dissipation increased by 72.42 % and 417 %. Interface separation speed was delayed by 300 % ∼ 400 %. Molecular simulations of interfacial separation aligned with AFM experimental results, where interfacial ion-pair, dynamics stability and polymer conformational changes provided insights for AFM experiment on adhesion force and delay of interface separation speed. Determination of interfacial mechanics by AFM experiment and insights by molecular simulation decoded CSH/PVP-co-PAA interfaces thoroughly.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"195 ","pages":"Article 107900"},"PeriodicalIF":10.9,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143859626","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":"Impact of pore solution composition and superplasticizers on the interparticle forces and rheology of metakaolin suspensions","authors":"S. Real ,&nbsp;P. Bowen ,&nbsp;R. Moreno ,&nbsp;L. González-Panicello ,&nbsp;F. Puertas ,&nbsp;M. Hanafi ,&nbsp;M. Palacios","doi":"10.1016/j.cemconres.2025.107901","DOIUrl":"10.1016/j.cemconres.2025.107901","url":null,"abstract":"<div><div>This study focuses on the influence of pH, aqueous phase composition and superplasticizers on the particle interactions in pure metakaolin suspensions. It was found increasing pH up to 11 led to the decrease of the particle agglomeration due to the higher OH⁻ adsorption onto metakaolin particles, which increased the absolute zeta potential and generates higher electrostatic repulsive forces. Above pH = 11, a slight increase in zeta potential was observed and colloidal stability was retained. Metakaolin suspensions prepared in Na₂SO₄ or Ca(OH)₂ at pH = 13 did not agglomerate. However, the simultaneous presence of Ca²⁺ and SO₄²⁻, led to particle agglomeration, which was enhanced as Ca²⁺ concentration increased. The rise of Ca²⁺ concentration in suspensions containing Ca²⁺ and SO₄²⁻ also induced higher yield stress values in metakaolin suspensions. The addition of polycarboxylate ether (PCE) superplasticizers deagglomerated metakaolin particles and decreased yield stress values in agreement with interparticle force modelling.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"195 ","pages":"Article 107901"},"PeriodicalIF":10.9,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143863494","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":"Investigation and evaluation on early-age crack resistance of ultra-high performance seawater sea-sand concrete with non-metallic fiber","authors":"Kaidi Jiang ,&nbsp;Xin Wang ,&nbsp;Lining Ding ,&nbsp;Qingguo Ben ,&nbsp;Zhiyuan Chen ,&nbsp;Jian Ding ,&nbsp;Xia Liu ,&nbsp;Zhishen Wu","doi":"10.1016/j.cemconres.2025.107906","DOIUrl":"10.1016/j.cemconres.2025.107906","url":null,"abstract":"<div><div>Ultra-high performance seawater sea-sand concrete (UHP-SSC) exhibits outstanding mechanical properties, but the high cracking potential of UHP-SSC under restrained conditions should not be neglected. As steel fibers pose a corrosion risk when used in UHP-SSC, this study investigated and assessed the crack resistance of UHP-SSCs reinforced with non-metallic fibers. Cracking experiments were conducted employing a slab test, and the influencing mechanism was investigated based on macro-fiber pullout testing, pore structure determination, autogenous shrinkage (AS) monitoring, and uniaxial tensile testing. Results revealed that both the twisted texture of macro-fibers and micro-fiber incorporation into the matrix can enhance bonding. Adding fibers increased the macroporosity, except for the basalt fiber. The fiber's mechanical properties were positively related to the reduction in AS, and increase in tensile performance, crack resistance. Meanwhile, with a partial replacement of macro-fibers with micro-fibers, multi-scale hybrid non-metallic fibers exhibited better anti-cracking ability than UHP-SSC reinforced with straight steel fibers.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"195 ","pages":"Article 107906"},"PeriodicalIF":10.9,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143863496","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":"Deriving early hydration cement paste phase assemblage, microstructure development and elastic properties using thermodynamic simulation and multi-scale material modeling","authors":"Eva Jägle ,&nbsp;Jithender J. Timothy ,&nbsp;Daniel Jansen ,&nbsp;Alisa Machner","doi":"10.1016/j.cemconres.2025.107830","DOIUrl":"10.1016/j.cemconres.2025.107830","url":null,"abstract":"<div><div>Many hydration models focus on predicting the long-term hydration process and resulting material changes without specifically addressing early hydration within the first day. Here, we present a new approach for predicting early hydration cement paste phase assemblage, microstructure development and elastic properties by applying thermodynamic modeling and simulation as input to a multi-scale material model. Cement dissolution for implementation within the thermodynamic simulation is derived by fitting the five-parameter logistic function (5PL) to experimental data from quantitative X-ray diffraction. Results are compared with simulations using the modified Parrot &amp; Killoh model for cement dissolution. Further, the influence of variations in the calcium sulphate and calcite content of the initial cement phase assemblage is investigated accounting for errors in experimental determination. The proposed model for hydrating cement paste accounts for all phases predicted by the thermodynamic simulation output, two types of C-S-H, as well as concentric growth of hydrates from the surface of the clinker grains. The stiffness of the hydrating cement paste is derived by upscaling the microscopic properties using a multi-level continuum micromechanics homogenization scheme. Model predictions are compared with experimental results from penetration tests and ultrasonic Young’s modulus determination.</div><div>It is shown, that 5PL dissolution modeling in combination with thermodynamic simulation is able to describe early hydration cement phase alterations. The 5PL approach thereby captures initial ettringite formation and accurately describes portlandite precipitation. However, the results are highly dependent on the quality of the experimental data. The results further illustrate, how cement paste stiffness development can be derived by application of low-cost computational methods. The proposed approach enables investigations of state-of-the-art questions of cement hydration including the influence of individual hydrate phases on the solidification process.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"195 ","pages":"Article 107830"},"PeriodicalIF":10.9,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143863495","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":"Alkali-carbonate reaction in concrete - Microstructural consequences and mechanism of expansion","authors":"Andreas Leemann ,&nbsp;Beat Münch ,&nbsp;Barbara Lothenbach ,&nbsp;Ellina Bernard ,&nbsp;Cassandra Trottier ,&nbsp;Frank Winnefeld ,&nbsp;Leandro Sanchez","doi":"10.1016/j.cemconres.2025.107903","DOIUrl":"10.1016/j.cemconres.2025.107903","url":null,"abstract":"<div><div>A detailed microstructural investigation of a concrete expanding due to alkali‑carbonate reaction (ACR) shows that the cement paste adjacent to reactive aggregate particles is carbonated, which leads to a sulfur redistribution resembling internal sulfate attack. Simultaneously to dedolomitization, partial dissolution of illite occurs in aggregate particles leading to the formation of brucite, hydrotalcite, magnesium-silicate-hydrate (M-S-H) and calcium‑aluminum-silicate-hydrate (C-A-S-H), in addition to calcite and thus to a substantial increase in solid volume. Thermodynamic modelling indicates that the simultaneous presence of illite and dolomite can accelerate the reactions within the aggregates. No alkali-silica reaction (ASR) products are observed. Dolomite, illite and all reaction products display a negative ζ-potential at high pH generating repulsive forces during dedolomitization. Together with the substantial increase in molar volume, the concrete expansion can be mainly attributed to the solidification pressure of hydrotalcite and M-S-H formation.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"195 ","pages":"Article 107903"},"PeriodicalIF":10.9,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143854562","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":"Synthesis and thermodynamic data of acetate-containing giorgiosite – a novel hydrated magnesium carbonate","authors":"Hoang Nguyen ,&nbsp;Ellina Bernard ,&nbsp;Frank Winnefeld ,&nbsp;Barbara Lothenbach ,&nbsp;Paivo Kinnunen","doi":"10.1016/j.cemconres.2025.107902","DOIUrl":"10.1016/j.cemconres.2025.107902","url":null,"abstract":"<div><div>Organic additives play important roles in enhancing the formation of Mg‑carbonates and reaction kinetics in MgO-based cements. However, little is known about the influences of organics on the formation pathways of carbonate phases and whether organo-modified Mg‑carbonates exist. We found that acetate can be involved in the formation of a new hydrated magnesium carbonate phase containing acetate: [Mg₅(CO₃)_3.25(OH)₂(CH₃COO)_1.5·5H₂O]. In this work, the solubility product (log K_s0) of this phase was reported for the first time, while we also re-calculated the log K_s0 of artinite. This acetate-containing giorgiosite is rather stable at low temperature but artinite [Mg₂(OH)₂(CO₃)(H₂O)₃] and amorphous magnesium carbonates were observed at 20 °C while hydromagnesite [Mg₅(CO₃)₄(OH)₂·4H₂O], hydrated carbonate brucite (HCB) and amorphous magnesium carbonates were present at 50 and 80 °C. The work enables the potential of using organic additives in steering the reaction and formation of carbonates for better efficacy of carbon utilization and reactions in MgO-based cements.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"195 ","pages":"Article 107902"},"PeriodicalIF":10.9,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143851858","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":"Estimation of Young's modulus and compressive strength of cement using a solitary wave in granular crystals","authors":"Ahmed Z. Alkhaffaf ,&nbsp;Sangyoung Yoon ,&nbsp;Andreas Schiffer ,&nbsp;Tadahiro Kishida ,&nbsp;Chan Yeob Yeun ,&nbsp;Tae-Yeon Kim","doi":"10.1016/j.cemconres.2025.107904","DOIUrl":"10.1016/j.cemconres.2025.107904","url":null,"abstract":"<div><div>This study presents an in-depth examination of the sensitivity of highly nonlinear solitary waves (HNSWs) to variations in the curing period, the water-to-cement (w/c) ratio, and the mechanical properties of cement. Experimental results verify that the travel times and amplitude ratios of the HNSWs are highly sensitive to changes in curing time of 1 to 28 days, the w/c ratio of 0.3 to 0.6, the elastic modulus of 0.225 to 2.39 GPa, and the compressive strength of 8.24 to 95.32 MPa. Based on the predictions of a numerical model, we establish a simple mathematical relation connecting the modulus and compressive strength of the sample with the delay of the first (i.e., primary) reflected HNSW. The latter relation is employed to evaluate the elastic modulus and compressive strength of the cement samples with different curing periods and w/c ratios, showing good agreement with the results obtained from destructive tests.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"194 ","pages":"Article 107904"},"PeriodicalIF":10.9,"publicationDate":"2025-04-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143847901","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":"Multiscale analysis on microstructural changes in hardened cement paste dried under different relative humidity levels: A comparison with cement paste containing water-dispersible polyurethane ether compound","authors":"Shingo Asamoto ,&nbsp;Keisuke Takahashi ,&nbsp;Naoki Sakamoto ,&nbsp;Tokio Sampei ,&nbsp;Kunio Matsui","doi":"10.1016/j.cemconres.2025.107896","DOIUrl":"10.1016/j.cemconres.2025.107896","url":null,"abstract":"<div><div>This study investigated microstructural changes in hardened cement paste with and without a water-dispersible polyurethane (PU) ether compound under varying relative humidity (RH) levels. The small-angle X-ray scattering technique was used to analyse the agglomeration, piling, and densification of calcium silicate hydrate (C-S-H) units. Mercury intrusion porosimetry and water vapour sorption isotherms were used to further characterise pore structures and surface areas, focusing on the C-S-H unit changes across different RH levels and the influence of PU. The presence of PU reduced variation in scattering profiles and subsequent calculated disc thickness at each RH, indicating the inhibition of C-S-H structural evolution during drying. These findings indicate less variation in the pore structure and surface area during the drying process than in the paste without PU. The length change isotherm of the cement paste with PU confirmed reduced shrinkage and hysteresis, which can be attributed to microstructural stabilisation.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"194 ","pages":"Article 107896"},"PeriodicalIF":10.9,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143834499","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}