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Polymorph and minor phase quantification in Portland clinker by X-ray powder diffraction analysis: Addressing challenges and foreign ion effects Cem. Concr. Res. (IF 10.9) Pub Date : 2025-01-29
Paulo R. de Matos, José S. Andrade Neto, Carlos E.M. Campos, Ruben Snellings, Robert E. Dinnebier, Ana P. KirchheimA comprehensive investigation of the phase composition of eight commercial clinkers was conducted through state-of-the-art synchrotron (SXRD) and laboratory (LXRD) X-ray diffraction, and supporting techniques. Challenges involved in polymorph and minor phase quantification, and the effects of foreign ions on the clinker chemistry were addressed. SXRD yielded higher C3S and lower C2S contents than LXRD
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Effects of Al in C–A–S–H gel on the chloride binding capacity of blended cement paste Cem. Concr. Res. (IF 10.9) Pub Date : 2025-01-30
Tiao Wang, Yuqian Zheng, Hao Qian, Zhenguo Shi, Satya Medepalli, Jin Zhou, Fuqiang He, Tetsuya Ishida, Dongshuai Hou, Gaozhang Zhang, Zhengwu Jiang, Zhengning Zhou, Wei ZhangThis study quantitatively examines the impact of aluminum (Al) in C–A–S–H gel2 on the chloride binding capacity of blended cement paste containing supplementary cementitious materials (SCMs). The experimental results show that Al incorporation does not influence the physical chloride binding of C–A–S–H gel, which is governed by its Ca/Si ratio. However, in the presence of Cl− ions, the OH− ligands
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Characterisation of steel corrosion and matrix damage in reinforced mortar combining analytical, electrical and image-based techniques Cem. Concr. Res. (IF 10.9) Pub Date : 2025-01-30
Andreas Alhede, Jelke Dijkstra, Alessandro Tengattini, Karin LundgrenCharacterising steel corrosion at the steel-concrete interface and linking it to concrete damage is challenging due to limitations of current non-destructive techniques. This study combines electrical resistance measurements, full-field image-based analyses and analytical techniques to comprehensively characterise steel corrosion and damage in small-scale specimens.X-ray and Neutron Computed Tomography
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Early hydration and viscoelastic properties of tricalcium aluminate pastes influenced by soluble sodium salts Cem. Concr. Res. (IF 10.9) Pub Date : 2025-01-30
Daniel Axthammer, Tobias Lange, Joachim Dengler, Torben GädtDuring the early hydration of ordinary Portland cement (OPC), tricalcium aluminate (C3A) exhibits the highest reactivity among the clinker phases. Consequently, C3A significantly influences the early rheological properties of OPC-based materials, thereby linking rheology with C3A reactivity. The reactivity of C3A is affected by temperature, calcium sulfates, admixtures, and ionic strength. Calcium
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Effects of Triethanolamine-Gallate on the workability, hydration and microstructure of steel slag supplementary cementitious materials Cem. Concr. Res. (IF 10.9) Pub Date : 2025-01-28
Bin Zeng, Xumin Zhuang, Shaojie Jia, Wenjin Han, Jingkui Zhong, Liwu Mo, Toshiharu KishiWidely used hydration promoters primarily improve the early strength of steel slag supplementary cementitious materials (SCMs) but offer limited enhancement to later strength and fail to mitigate early hydration inhibition by steel slag (SS). This study introduces a novel organic hydration promoter, Triethanolamine-Gallate (TG), synthesized by modifying gallic acid with triethanolamine. TG imparted
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Discrete element modeling on nanoindentation creep behavior of C-S-H under berkovich and flat-tip indenters Cem. Concr. Res. (IF 10.9) Pub Date : 2025-01-28
Weiqiang Guo, Ya WeiThis paper employs the discrete element method (DEM) to simulate the nanoindentation creep of calcium-silicate-hydrate (C-S-H), focusing on indentation deformation, particle interactions, and stress transmission paths. The Rate Process Theory (RPT), previously utilized in the creep modeling of cohesive soils and other granular materials, is proposed to simulate C-S-H creep. Due to the nanometer size
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Which factors impact the effectiveness of PCEs in alkali-activated slag cements? Cem. Concr. Res. (IF 10.9) Pub Date : 2025-01-27
Jiaxin Chen, Johann PlankBehavior of different PCEs (MPEG (methacrylate ester), HPEG (methallyl ether), EPEG (2-hydroxyethyl poly(ethylene glycol) vinyl ether) based PCE) in NaOH-/Na2SiO3-activated two-part slag binders was investigated. In both activator solutions their solubility follows the order MPEG> HPEG> EPEG according to “cloud point” method. GPC chromatograms confirmed that at RT all PCEs don't decompose in activator
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The monocarbonate Ca2Al1-xFex(OH)6·½CO3·nH2O AFm system Cem. Concr. Res. (IF 10.9) Pub Date : 2025-01-24
Aurore Lechevallier, Yunge Bai, Antoine Rochelet, Rodolphe Thirouard, Mohend Chaouche, Evelyne Prat, Jérôme Soudier, Guillaume RenaudinWith the growing emphasis on reducing CO2 emissions, new hydraulic binders are gaining attention. Understanding the hydration products of these new binders is crucial. This study investigates mixed Al/Fe-CO3 AFm hydrates. This research proposes two methods to synthesize CO3-AFm phases with varying proportions of trivalent Al3+ and Fe3+ cations, followed by a thorough characterization of the samples
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High-temperature strengthening of Portland cementitious materials by surface micro-ceramization Cem. Concr. Res. (IF 10.9) Pub Date : 2025-01-18
Weizheng Shi, Zixiao Wang, Chaoqun Li, Qingya Sun, Weiqiang Wang, Shuxin Deng, Weijin Li, Aming XieThis work prepares a novel cementitious material with high-temperature strengthening by adding titanium diboride (TiB2) powders into Portland cement. The influences of TiB2 on the physicochemical properties of paste samples before and after high-temperature treatment (the maximum is 900 °C) are investigated. Results indicated that the pore structure of hardened paste is refined after curing because
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Effects of varying grades/pretreatments of recycled aggregates on the development of pore structures and ITZs within reactive magnesia cement (RMC) concrete Cem. Concr. Res. (IF 10.9) Pub Date : 2025-01-17
Yufeng Song, Jiaze Wang, Yinjie Huang, Jiawen Wang, Yitian Weng, Rui Ma, Kevin Seng Hong Pang, Shaoqin RuanThis study explores the influence of incorporating recycled aggregate (RA) and CO2-pretreated recycled aggregate (CRA) in reactive magnesia concrete (RMC) formulations. Through comprehensive microscopic characterizations, the phase composition, carbonation degree, pore structure, and interfacial transition zone (ITZ) characteristics are examined in both interior and exterior regions of specimens. The
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Corrigendum to “Influence of silica fume addition and content on the early hydration of calcium aluminate cement — The role of soluble silicon” [Cem. Concr. Res. 184 (2024) 107618] Cem. Concr. Res. (IF 10.9) Pub Date : 2025-01-17
Tillmann Schramm, Jürgen Neubauer, Friedlinde Goetz-NeunhoefferThe authors regret a calculation error regarding the dilution factor which affects the absolute ion concentration values stated in the above paper and therefore also the corresponding calculated saturation indices. All stated concentration values (text and figures) need to be multiplied by a factor of 2.25. However, the authors would like to highlight that this does not affect any statements or conclusions
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Surface whitening mechanism of ettringite rich decorative mortar Cem. Concr. Res. (IF 10.9) Pub Date : 2025-01-16
Xianping Liu, Hanqing Gao, Hervé Fryda, Peiming WangThis study investigates the surface whitening mechanism of ettringite rich decorative mortars. Surface whitening was triggered through an exaggerated test scenario with a highly porous simplified mortar and a series of wet/dry cycles. Based on correlative light-electron microscopy observation, soak solution and mineralogical composition analyses, a mechanism is proposed: surface whitening is due to
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Dipotassium hydrogen phosphate activated Al-rich steel slag: The role of layered double hydroxides and aluminum hydrate gel Cem. Concr. Res. (IF 10.9) Pub Date : 2025-01-10
Mengyu Zhu, Qingliang Yu, S.R. van der Laan, Yuxuan ChenDue to absence of C-S-H gel, chemically activated mixed Al-rich steel slag often shows low early-age strength. This work proposes a novel method to accelerate the hydration of Al-rich steel slag by dipotassium hydrogen phosphate (DHP) activation. Results reveal that DHP significantly promotes the formation of layered double hydroxides (LDHs) by increasing pH of the pore solution and supplying phosphate
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Effect of curing regimes on composition and microstructure of blended pastes: Insight into later-age hydration mechanism Cem. Concr. Res. (IF 10.9) Pub Date : 2025-01-09
Liming Huang, Luping Tang, Zhijun Dong, Birhan Alkadir Abdulahi, Zhenghong YangUnderstanding the hydration of composite binders is essential for decarbonizing the cement industry. This study investigated the microstructure and composition of pastes with either fly ash or slag after different long-term curing. Results show that the elevated temperature slightly reduces the capillary pore volume and internal RH of sealed samples. Water curing largely enhances hydration of fly ash
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Plastic shrinkage of concrete made with calcined clay-limestone cement Cem. Concr. Res. (IF 10.9) Pub Date : 2025-01-09
Mateusz Wyrzykowski, Carmelo Di Bella, Davide Sirtoli, Nikolajs Toropovs, Pietro LuraConcrete made with blended cements with high clinker replacement ratios may be at higher risk of plastic shrinkage cracking when experiencing high evaporation rates immediately after casting. This paper investigates the plastic shrinkage behavior of concretes made with a cement with clinker replacement by a blend of calcined clay and limestone, which was compared to a conventional Portland cement and
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Thermal properties of tricalcium aluminate: Molecular dynamics simulation and experimental approach Cem. Concr. Res. (IF 10.9) Pub Date : 2025-01-06
Prodip Kumar Sarkar, Guido Goracci, Jorge S. Dolado -
The influence of portlandite, calcite, quartz and ettringite inclusions on the multiscale mechanical behaviors of C-S-H matrix Cem. Concr. Res. (IF 10.9) Pub Date : 2025-01-04
Zhe Zhang, Yuchen Hu, Lianyao Xiong, Guoqing GengC-S-H is the primary binder in cement mixed with additional phases. It is essential to understand how different phases impact cement strength. This study presents an innovative method for preparing a binary system doped with C-S-H and additional phases to study the effects of these phases on the composite's strength. By blending C-S-H with various minerals, we control mineral content precisely. Using
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Active rheology control of cementitious materials: New insights from magneto-responsive aggregates Cem. Concr. Res. (IF 10.9) Pub Date : 2024-12-31
Yiyuan Zhang, Yaxin Tao, Jose R.A. Godinho, Kim Van Tittelboom, Karel Lesage, Geert De SchutterThis study aims to achieve active rheology control of cementitious materials from the new view of magneto-responsive aggregates. It provides a sound experimental validation, qualitative analysis and quantitative characterization of magnetorheological response and mechanism of cementitious materials containing responsive aggregates under a nozzle/pipe-like (inline) external magnetic field. Specially
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Mesoscopic mechanisms of dicalcium silicate dissolution Cem. Concr. Res. (IF 10.9) Pub Date : 2024-12-31
Yong Tao, Pablo Martin, Hegoi Manzano, Mohammad Javad Abdolhosseini QomiDicalcium silicate dissolution is crucial in cement hydration and provides long-term durability. However, our understanding of its dissolution process is limited due to its multiscale nature. To resolve this limitation, we combine rare event molecular dynamics and kinetic Monte Carlo (KMC) techniques. At the nanoscale, we reveal the relationship between surface Ca2+ coordination chemistry and dissolution
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Semi-dry natural carbonation at different relative humidities: Degree of carbonation and reaction kinetics of calcium hydrates in cement paste Cem. Concr. Res. (IF 10.9) Pub Date : 2024-12-30
Naohiko Saeki, Ryo Kurihara, Takahiro Ohkubo, Atsushi Teramoto, Yuya Suda, Ryoma Kitagaki, Ippei MaruyamaThis study investigated semi-dry carbonation at different relative humidities (RH) under atmospheric CO2 concentrations to determine the effect of RH on the degree of carbonation (DoC) and reaction rates. The carbonation kinetics of each calcium-containing hydrate exhibited an initial rapid chemical-reaction-limited stage, followed by a significantly slower stage. DoC values plateaued after 200 days
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Phase profiling of carbonation-cured calcium sulfoaluminate cement Cem. Concr. Res. (IF 10.9) Pub Date : 2024-12-30
Jihoon Park, Joonho Seo, Solmoi Park, Alam Cho, H.K. LeeThe present study investigated the effect of CO2 concentration during carbonation curing on the microstructural evolution of calcium sulfoaluminate (CSA) cement. Carbonation curing was performed for 28 d at 3 % and 10 % CO2 concentrations. To profile the microstructure, samples were collected from the surface of the cement to a depth of 30 mm on set curing days. At 3 % CO2 concentration, vaterite and
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Impact of polymer binders on the aggregation modes of two-pieces CSH composites Cem. Concr. Res. (IF 10.9) Pub Date : 2024-12-29
Jiwei Jia, Ali Zaoui, W. SekkalUsing polymer binders in cementitious materials significantly boosts their structural stability and durability for civil engineering applications. This study explored the role of polymeric binders in enhancing the morphological stability of calcium silicate hydrates (CSH) paste through molecular dynamics simulations. Most pure CSH configurations displayed larger voids and decreased stability, especially
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Discussion of the paper “Effect of the chemical composition of synthetic alkali-silica gels on their structure, swelling behavior and water uptake” by Miriam E. Krüger, Harald Hilbig, Ludwig Stelzner and Alisa Machner, Cem. Conc. Res. 184 (2024): 107596 Cem. Concr. Res. (IF 10.9) Pub Date : 2024-12-29
Andreas LeemannIn the discussed study, synthesized ASR products of unknown internal relative humidity (RH) were brought into contact with water using the osmotic cell test. They were not conditioned to an identical RH corresponding to the one of ASR affected concrete before the test. Moreover, swelling and osmotic pressure depend on the difference in the ionic concentration between two solutions. ASR products formed
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Effects of environmental exposure on Portland cement Type IL Cem. Concr. Res. (IF 10.9) Pub Date : 2024-12-24
Rotana Hay, Parham AghdasiThis study investigates the physico-chemical change in a Type IL cement prehydrated in the natural environment for 7, 14, and 21 days. A focus was made on the reaction kinetics, product formation, and strength development using calorimetry, XRF, QXRD, TGA and compressive testing. It was found that prehydration converted hemihydrate to gypsum and partially transformed the principal cement phases and
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Impact of nesquehonite on hydration and strength of MgO-based cements Cem. Concr. Res. (IF 10.9) Pub Date : 2024-12-20
Paula Montserrat-Torres, Frank Winnefeld, Barbara LothenbachHydrated magnesium carbonate cements prepared from MgO and carbonates such as hydromagnesite (Mg5(CO3)4(OH)2·4H2O) or nesquehonite (MgCO3ˑ3H2O) have potential for carbon sequestration during hardening. This study investigates the hydration of MgO/nesquehonite blends with up to 50 wt% of nesquehonite. Nesquehonite is highly reactive in the presence of MgO and water. The replacement of 50 wt% MgO by
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An experimental review of the reaction paths followed by alkali-activated slag pastes Cem. Concr. Res. (IF 10.9) Pub Date : 2024-12-17
C. Paillard, N. Sanson, J.-B. d’Espinose de Lacaillerie, M. Palacios, P. Boustingorry, M. Jachiet, C. Giraudeau, V. Kocaba -
On the variability of industrial Portland cement clinker: Microstructural characterisation and the fate of chemical elements Cem. Concr. Res. (IF 10.9) Pub Date : 2024-12-16
Wahab Abdul, Christiane Rößler, Holger Kletti, Chancel Mawalala, Alexander Pisch, Marcus N. Bannerman, Theodore HaneinPortland cement (PC) has been used and developed since the early 19th century. Although the compositional ranges of PC clinkers are generally specified in standards, there is a lack of information on the variability of industrial clinkers. Furthermore, with an increase in the use of alternative mineral and fuel feeds, it is important to understand the evolution of clinker chemistry and mineralogy which
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Production of alinite-chlormayenite clinker and its hydration behavior with increasing gypsum content Cem. Concr. Res. (IF 10.9) Pub Date : 2024-12-12
Marco Simoni, Aniruddha Baral, Zhili Ren, Tristana Y. Duvallet, Robert B. Jewell, Christiane Rößler, Theodore HaneinAn alternative low-energy alinite-chlormayenite clinker was produced and its hydration with different gypsum content was studied. The clinker was produced at 1225 °C using reagent-grade materials in an electric kiln with alinite, larnite, and chlormayenite content of 48, 24, and 16 wt%, respectively. The hydration kinetics of the clinker with different gypsum additions (0,10, 20, and 40 wt%) did not
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Modeling and simulation of alkali-activated materials (AAMs): A critical review Cem. Concr. Res. (IF 10.9) Pub Date : 2024-12-10
Yibing Zuo, Yun Chen, Chen Liu, Yidong Gan, Luise Göbel, Guang Ye, John L. ProvisAlkali-activated materials (AAMs) are a class of potentially eco-friendly construction materials that can contribute to reduce the environmental impact of the construction sector by offering an alternative to Portland cement (PC). With the rapid development of both computational capabilities and theoretical insights into alkali-activation reaction processes, there has been a surge in research activities
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Reaction kinetics of calcined smectite in a clinker-free model and a synthetic cement system in comparison with selected calcined phyllosilicates Cem. Concr. Res. (IF 10.9) Pub Date : 2024-12-08
Sebastian Scherb, Matthias Maier, Köberl Mathias, Nancy Beuntner, Karl-Christian ThienelThe investigations of clinker-free model and synthetic cement systems reveal deeper insight into the behavior of metasmectite during early hydration. The use of metasmectite accelerates the aluminate clinker reaction and influences the degree of hydration of alite. Its chemical reactivity can be demonstrated in clinker-free as well as model cement systems by direct quantification of the metasmectite
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Understanding hydration reactions, mechanical properties, thermal expansion, and organic interfacial interactions of calcium sulfate hydrates from the atomic scale Cem. Concr. Res. (IF 10.9) Pub Date : 2024-12-08
Ratan K. Mishra, Samir Darouich, Pieter J. in 't Veld, Robert J. Flatt, Hendrik HeinzCalcium sulfates such as anhydrite, hemihydrate, and gypsum are used extensively in building materials, wall board, and biomaterials. The correlation between nanoscale structure and macroscopic properties, however, remains incompletely understood. We employed molecular dynamics simulations with the Interface Force Field (IFF) to examine sensitive hydration reactions, anisotropic thermal and mechanical
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Drying shrinkage and carbonation of steel slag-metakaolin alkali-activated composites: Effect of vegetable oil addition and slag aggregates Cem. Concr. Res. (IF 10.9) Pub Date : 2024-12-06
O. Rudić, C. Grengg, Y. Seyrek, F. Steindl, B. Müller, I. Zögl, D. Wohlmuth, N. Ukrainczyk, F. MittermayrThe influence of vegetable oil and steel slag aggregates on the drying shrinkage and carbonation performance of steel slag-based alkali activated materials was investigated. Decrease in carbonation rates by up to 19% attributed to the formation of metal soap phases which strongly reduced the gel and small capillary porosity as well as the specific surface area of the materials. When combined with steel
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Revealing the tricalcium silicate formation behaviors in modified EAF slag at high temperatures for the production of electric recycled cement Cem. Concr. Res. (IF 10.9) Pub Date : 2024-12-06
Mingrui Yang, Zhiming Yan, Zushu LiThe formation behaviors of tricalcium silicate (C3S) in modified EAF slag were investigated to assess the feasibility of using EAF slag for cement clinker production. For the formation conditions of C3S, the C3S content in slag exhibits a notable increase with elevating slag basicity and reaction time, while only a slight enhancement with temperature rising from 1400 °C to 1500 °C. The C3S formation
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Pyroaurite-like phases (Mg-Fe3+ LDH) synthesis and solubility Cem. Concr. Res. (IF 10.9) Pub Date : 2024-12-05
Ellina Bernard, Barbara Lothenbach, Rupert J. Myers, Marcus H.N. YioThis study explores different methods for precipitating carbonated Mg-Fe3+ layered double hydroxides (LDHs) with Mg/Fe3+ ratios ranging from 2 to 2.5. Two synthesis approaches were investigated: a) CO3-Mg-Fe3+-LDH co-precipitated directly from MgO, Fe(NO3)3 and Na2CO3 and b) NO3-Mg-Fe3+-LDH precipitated by adding NaOH to Mg(NO3)2-Fe(NO3)3 solutions, followed by ion exchange with Na2CO3 to form CO3-Mg-Fe3+-LDH
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Estimation of cement content in concrete by spatially resolved laser induced breakdown spectroscopy Cem. Concr. Res. (IF 10.9) Pub Date : 2024-12-05
Tobias Völker, Friedrich M. Mensing, Sabine KruschwitzThe cement content in concrete significantly influences critical properties such as durability, permeability, strength, and workability. Traditional methods for estimating the cement content face limitations. These include the need for comprehensive chemical and solubility knowledge, extensive sample preparation, and their time-consuming and destructive nature. This study investigates the application
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Basic creep properties of hydrates in mature slag-based CEM II concretes: A micromechanical analysis Cem. Concr. Res. (IF 10.9) Pub Date : 2024-12-05
Maximilian Sorgner, Rodrigo Díaz Flores, Bernhard Pichler, Thomas Pilgerstorfer, Bernd Moritz, Christian HellmichThe demand for accurate characterization of slag-based CEM II concretes is becoming increasingly important as the construction sector shifts towards eco-efficient materials. Here, the basic creep behavior of slag-based CEM II concretes is traced back to mixture-invariant hydrate properties. Therefore, an experimentally validated three-step micro-viscoelastic model for CEM I/OPC-concretes is complemented
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Effect of temperature on the solubility of xonotlite Cem. Concr. Res. (IF 10.9) Pub Date : 2024-12-02
S. Mingione, D. Jansen, F. Winnefeld, S.V. Churakov, B. LothenbachXonotlite forms under hydrothermal conditions and it dehydrates to β-wollastonite between 770 and 800 °C under atmospheric pressure. The solubility of xonotlite is poorly known, as the experimental datasets reported in literature differ by as much as 10 log units. This study investigates the impact of temperature (7, 20, 50 and 80 °C) on the solubility of xonotlite by dissolution experiments from undersaturation
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Changes in cement paste during accelerated mortar bar testing for pyrrhotite containing aggregate Cem. Concr. Res. (IF 10.9) Pub Date : 2024-12-02
K. De Weerdt, M. Bagheri, J. Lindgård, H. Lindstad, A. Rodrigues, J. Duchesne, P.-L. Fecteau, M.K. Haugen, T. Danner, B.J. Wigum, N. Oberhardt, K. Aasly, B. LothenbachThe accelerated mortar bar test (AMBT) for pyrrhotite (Fe1-xS) containing aggregates accelerates expansion using two regimes: Phase I, during which Fe1-xS oxidation to iron hydroxide is accelerated by bleach and storage at 80 °C; Phase II that promotes thaumasite formation with continued bleach soaking and storage at 4 °C. Two bleach concentrations and one aggregate containing 0.5 wt% Fe1-xS are tested
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Comparative evaluation of laboratory methods for performance assessment of cementitious materials in wastewater networks: Biological and chemical tests versus field exposure Cem. Concr. Res. (IF 10.9) Pub Date : 2024-11-30
Alexandra Bertron, Cyrill Grengg, Matthieu Peyre Lavigne, Holger Wack, Gregor J.G. Gluth, Amr Aboulela, Vanessa Sonois, Tilman Gehrke, Florian MittermayrThe biodeterioration of concrete elements in sewer systems and their repair is of significant economic and societal concern. However, the available test methods to assess the performance of cementitious materials under the relevant conditions are insufficiently validated. In the present study, two biological test methods and a standardised chemical test were applied to two sewer repair mortars and
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Effect of flow rate on spatio-temporal deterioration of concrete under flowing sulfate attack Cem. Concr. Res. (IF 10.9) Pub Date : 2024-11-28
Fujian Yang, Zhihao Zhao, Yuan Liu, Man Li, Jinliang Song, Dawei Hu, Hui ZhouFlowing effect on concrete deterioration caused by sulfate attack at varying flow rates was studied. It was found that an increased flow rate can expedite the weakening of the concrete's elastic modulus in the short term, thus causing an earlier onset of this weakening. However, the long-term deterioration of the elastic modulus remains unaffected by the flow rate due to the limited amount of products
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Reaction and microstructure development of one-part geopolymer for wellbore applications – An experimental and numerical study Cem. Concr. Res. (IF 10.9) Pub Date : 2024-11-26
Mayank Gupta, Xiujiao Qiu, Mohamed Omran, Yun Chen, Mahmoud Khalifeh, Guang YeThis study focuses on the numerical modeling of the reaction and microstructure development of a one-part granite-based geopolymer, which is often used for carbon capture and storage (CCS) applications. This work extends the capabilities of GeoMicro3D to model one-part geopolymers containing different precursors and activators (solid and in solution). The model considers the particle size distribution
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Penetration test of sheet-like indenter for yield stress assessment of 3D-printed concrete Cem. Concr. Res. (IF 10.9) Pub Date : 2024-11-26
Haoyu Lu, Lizhi Zhang, Junkai Wang, Zhaoxin Shi, Wei She, Wenqiang ZuoThe evolution of early mechanical properties of 3D-printed concrete (3DPC) plays a crucial role in early constructability, while current methods face challenges on the tradeoff between the accuracy and feasibility of mechanical properties characterization. In this paper, we designed a sheet-like indenter configuration to quantitatively obtain the yield stress of fresh 3DPC. First, we show the typical
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Quantitative relationship between microstructure of steel-concrete interface and chloride-induced corrosion rate of steel in unsaturated cementitious materials Cem. Concr. Res. (IF 10.9) Pub Date : 2024-11-25
Zushi Tian, Xiaojuan Kang, Haodong Ji, Hailong YeWhile extensive evidence indicates that the porous microstructure of the steel-concrete interface (SCI) is the key factor contributing to early depassivation and expedited corrosion propagation of steel rebar, there remains a lack of quantitative relationship between the SCI microstructural parameters and corrosion rate of steel, particularly under unsaturated conditions. In this work, the effects
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Rheology dependent pore structure optimization of high-performance foam concrete Cem. Concr. Res. (IF 10.9) Pub Date : 2024-11-25
Dingqiang Fan, Chunpeng Zhang, Jian-Xin Lu, Ligang Peng, Rui Yu, Chi Sun PoonFoam concrete encounters a fundamental challenge in balancing lightweight and high strength. Pore optimization is the key to address this problem. This study starts with rheology control to optimize the pore structure of foam concretes, thereby designing high-performance foam concrete (HPFC). X-ray computed tomography was employed to explore the relationship between rheology and pore characteristics
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Rheology control of cement paste by in-situ polymerization for 3D printing applications Cem. Concr. Res. (IF 10.9) Pub Date : 2024-11-21
Zhaoyang Sun, Yuyang Zhao, Dongshuai Hou, Zongjin Li, Binmeng ChenRheology control is the most critical determinant of success in 3D concrete printing (3DCP), typically achieved through the hydration control of cement. However, this inevitably leads to overdesign of printed concrete featuring a low water-to-binder ratio (w/b), which is incompatible with its non-load bearing purpose and raises a series of environmental and durability problems, such as high carbon
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Reactive transport modelling of autogenous self-healing in cracked concrete Cem. Concr. Res. (IF 10.9) Pub Date : 2024-11-21
Daniel Lahmann, Sylvia KeßlerAutogenous self-healing can close cracks in water-retaining concrete structures. However, its inconsistent efficiency in building practice indicates that the underlying processes are not fully understood. Therefore, this study characterizes reactive transport through cracked concrete and models it using PHREEQC to develop a comprehensive understanding of chemical processes promoting autogenous self-healing
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Ca/Si-dependent size of silica nanoparticles derived from C-S-H at high water to solid ratio Cem. Concr. Res. (IF 10.9) Pub Date : 2024-11-20
Binmeng Chen, Xu Fang, Yuyang Zhao, Zongjin LiIn recycling and reusing construction waste, carbonation of recycled concrete fine (RCF) has been successfully applied to produce value-added products, such as silica nanoparticles, via the breaking of calcium silicate hydrate (C-S-H) structure and condensation of silicate chains. However, the intricacies of carbonation of RCF with varying calcium to silicon (C/S) ratios and their implications on the
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A new model for investigating the formation of interfacial transition zone in cement-based materials Cem. Concr. Res. (IF 10.9) Pub Date : 2024-11-20
Xuan Gao, Qing-feng Liu, Yuxin Cai, Liang-yu Tong, Zesen Peng, Qing Xiang Xiong, Geert De SchutterThe interfacial transition zone (ITZ), located between aggregate and cement paste, has the features of high porosity, low unhydrated cement content, and enrichment of calcium hydroxide crystals (CH) and is often regarded as the weak link in cement-based materials. The present study is devoted to investigating the influence of multiple mechanisms or factors on ITZ formation, including the wall effect
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Modelling and experimental study on static yield stress evolution and structural build-up of cement paste in early stage of cement hydration Cem. Concr. Res. (IF 10.9) Pub Date : 2024-11-20
Yanliang Ji, Ursula Pott, Alexander Mezhov, Christiane Rößler, Dietmar StephanStatic yield stress is crucial for concrete, especially for 3D printed concrete, as it determines whether the bottom layer can support the load of the subsequent layers or withstand any potential impulses. A better understanding of the evolution of the static yield stress and its changing mechanism is therefore needed. Under the assumption that hydrate formation follows fractal patterns, this work
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Expansion of irregularly shaped aggregate induced by alkali-silica reaction: Insights from numerical modeling Cem. Concr. Res. (IF 10.9) Pub Date : 2024-11-18
Lifu Yang, Zhenguo Shi, Kai Li, Xiang Hu, Caijun ShiThis study presents a homogenization approach to understand and simulate the heterogeneous expansion of irregularly shaped aggregate induced by alkali-silica reaction (ASR). The analysis employs a cubic representative volume element (RVE) containing a single reactive aggregate with an arbitrary shape embedded in a mortar matrix. At the aggregate level, ASR expansion is characterized by applying a homogeneous
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3D microstructural generation from 2D images of cement paste using generative adversarial networks Cem. Concr. Res. (IF 10.9) Pub Date : 2024-11-16
Xin Zhao, Lin Wang, Qinfei Li, Heng Chen, Shuangrong Liu, Pengkun Hou, Jiayuan Ye, Yan Pei, Xu Wu, Jianfeng Yuan, Haozhong Gao, Bo YangEstablishing a realistic three-dimensional (3D) microstructure is a crucial step for studying microstructure development of hardened cement pastes. However, acquiring 3D microstructural images for cement often involves high costs and quality compromises. This paper proposes a generative adversarial networks-based method for generating 3D microstructures from a single two-dimensional (2D) image, capable
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Unveiling the key factors for clinker reactivity and cement performance: A physic-chemical and performance investigation of 40 industrial clinkers Cem. Concr. Res. (IF 10.9) Pub Date : 2024-11-14
J.S. Andrade Neto, I.C. Carvalho, P.J.M. Monteiro, P.R. de Matos, A.P. KirchheimThis study assessed 40 industrial clinkers from 16 cement plants, determining their physical, chemical, and mineralogical properties and the corresponding cements' strength development and hydration kinetics. Pearson's statistical analysis identified key factors influencing clinker and cement properties. Clinker composition ranged within 56.5–73.9% C₃S, 4.1–24.5% C₂S, 0.8–8.4% C₃A, and 7.4–13.9% C₄AF
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3D crystalline phase and pore structure evolution upon CO2 exposure in sodium sulfate-activated cement pastes Cem. Concr. Res. (IF 10.9) Pub Date : 2024-11-11
Zengliang Yue, Zixian Su, Partha P. Paul, Alastair T.M. Marsh, Alice Macente, Marco Di Michiel, John L. Provis, Philip J. Withers, Susan A. BernalThe effects of CO2 exposure on sodium sulfate-activated blast furnace slag cement paste have been characterised by X-ray (attenuation) computed tomography revealing changes in micron-scale pore structure, and X-ray diffraction computed tomography (XRD-CT) elucidating changes in the spatial distribution of crystalline and semi-crystalline phases. Accelerated carbonation reduced ettringite volumes and
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Degradation of alkali-activated Fe-rich slag in acetic acid Cem. Concr. Res. (IF 10.9) Pub Date : 2024-11-09
Nana Wen, Ziyou Yu, Vincent Hallet, Arne Peys, Dimitrios Sakellariou, Yiannis PontikesAlkali-activated Fe-rich non-ferrous metallurgical slags (AA-NFMS) emerge as a novel, sustainable cementitious binder, but durability performance is one of the crucial parameters to assess their success. This paper investigates the degradation mechanisms of AA-NFMS in 4 wt% acetic acid (AcH) solutions, commonly found in agricultural industries. The results indicated that upon AcH exposure, the amorphous
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Reactive transport modeling of acetic acid-induced degradation in portland cement paste Cem. Concr. Res. (IF 10.9) Pub Date : 2024-11-08
Maximilian Löher, Neven Ukrainczyk, Andreas Bogner, Astrid Hirsch, Frank Dehn, Eduardus KoendersA reactive transport model was employed to investigate the influence of multiple hydrate phases during acetic acid attack on Portland cement paste. The simulation accounted for the dissolution of primary cement hydrates like Ettringite, Portlandite and C-S-H, along with the formation of silica gel products impacting diffusivity. The simulations primarily utilized independent material parameters, though
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Influence of ultra-fine pozzolanic materials on the self-healing capabilities of ultra-high performance concrete under carbonation conditioning Cem. Concr. Res. (IF 10.9) Pub Date : 2024-11-06
Qiaomu Zheng, En-hua Yang, Chen Li, Qiang Ren, Hongen Zhang, Facheng Song, Bo Liu, Zhengwu JiangThis work studies the autogenous self-healing of ultra-high performance concrete (UHPC) incorporating two ultra-fine pozzolanic materials, silica fume (USF) and ultra-fine fly ash (UFFA), under carbonation conditioning. Both ultra-fine pozzolanic materials stimulate the healing of cracks by promoting the secondary hydration of the cement matrix. USF and UFFA form healing products primarily consisting
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Hourly three-minute creep testing of an LC3 paste at early ages: Advanced test evaluation and the effects of the pozzolanic reaction on shrinkage, elastic stiffness, and creep Cem. Concr. Res. (IF 10.9) Pub Date : 2024-11-06
Sophie J. Schmid, Luis Zelaya-Lainez, Olaf Lahayne, Martin Peyerl, Bernhard PichlerIn this study, hourly three-minute creep testing is used to elucidate the evolution of the viscoelastic behavior of cement pastes produced with ordinary Portland cement (OPC), limestone Portland cement (LPC), and limestone calcined clay cement (LC3), from 1 to 7 days after production. An innovative test evaluation protocol, accounting for shrinkage, is used to identify values of the elastic modulus
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Insight into the direct carbonation process of Ca2SiO4 based on ReaxFF MD simulation and experiments Cem. Concr. Res. (IF 10.9) Pub Date : 2024-11-04
Ya-Jun Wang, Xiao-Pei Zhang, Dong-Mei Liu, Jun-Guo Li, Jian-Bao Zhang, Yu-Wei Zhang, Ya-Nan Zeng, Yi-Tong Wang, Bao Liu, Xi Zhang, Ya-Jing Zhang