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Discussion: Towards performance-based specifications for fly ash and natural pozzolans-insights from a Monte-Carlo based thermodynamic modeling framework Cem. Concr. Res. (IF 10.9) Pub Date : 2024-06-27 Galal Fares, Jieying Jane Zhang
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The role of biotite in the deterioration of pyrrhotite within concrete aggregates: Trois-Rivières case study Cem. Concr. Res. (IF 10.9) Pub Date : 2024-06-26 Bruno Titon, Josée Duchesne, Benoît Fournier
In Trois-Rivières, Canada, numerous commercial and residential structures suffered severe concrete degradation due to internal sulfate attack (ISA). The deterioration was attributed to the use of sulfide-bearing aggregates obtained from nearby quarries. The objective of this study was to investigate the mechanisms involving pyrrhotite oxidation and the role of biotite in this process. Detailed analysis
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Thermoelectric properties of the main species present in Portland cement pastes Cem. Concr. Res. (IF 10.9) Pub Date : 2024-06-26 Ridwan O. Agbaoye, Jozef Janovec, Andrés Ayuela, Jorge S. Dolado
Several experimental studies have been conducted on the thermoelectric properties of cementitious materials, but a detailed inspection of the intrinsic properties of their main ingredients is still missing. This work focuses on the thermoelectric properties of portlandite and tobermorite, two mineral components found in Ordinary Portland Cement pastes. To this end, atomistic simulations were carried
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Binary solid wastes derived clinker: Raw feed system design validation and thermodynamic simulation investigation Cem. Concr. Res. (IF 10.9) Pub Date : 2024-06-25 Lu Zhu, Hanxiong Lyu, Yang Liu, Shipeng Zhang, Chi Sun Poon
Solid waste derived clinker design methodology was established based on thermodynamic simulation and experiment validation via the recycling of incinerated sewage sludge ash (ISSA) and recycled concrete fine (RCF). Compared with 1000 °C and 1100 °C, 1200 °C was the optimum temperature for CS-rich clinker synthesis due to the highest simulated belite content after sintering. A utilization rate of 95 %
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pyCSH: Automated atomic-level structure generation of bulk C-S-H and investigation of their intrinsic properties Cem. Concr. Res. (IF 10.9) Pub Date : 2024-06-24 Ziga Casar, Jon López-Zorrilla, Hegoi Manzano, Eduardo Duque-Redondo, Aslam Kunhi Mohamed, Karen Scrivener, Paul Bowen
A new Python code for the automated generation of realistic bulk calcium silicate hydrate (C-S-H) structures is introduced. The code was used to generate 400 structures with Ca/Si of 1.3, 1.5, 1.7, and 1.9. The generated structures are in excellent agreement with experimentally measured C-S-H properties (Ca/Si, 2H/Si, MCL, Si-OH/Si, and Ca-OH/Ca). Molecular dynamics was used to simulate the structures
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Alkali-activated calcined clay blended cement: Effect of NaOH activator on performance of HPEG PCEs and on early strength Cem. Concr. Res. (IF 10.9) Pub Date : 2024-06-20 Jiaxin Chen, Johann Plank
The effect of NaOH on dispersing performance of HPEG PCE superplasticizers and early strength was studied in a calcined clay (CC) blended cement (OPC:CC = 70:30 wt./wt.). Activator impact on workability and mechanical properties was investigated on mortar via fluidity and strength tests. The results revealed a time-dependent impact. At early ages (16 h – 3 d), the strength of the NaOH-activated OPC/CC
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Build-up and consolidation of an attractive network of particles in cement-based pastes Cem. Concr. Res. (IF 10.9) Pub Date : 2024-06-14 Omar Ojeda-Farías, Didier Lootens, Pascal Hébraud
The very early age flocculation of a cement based paste, in which cement is partially substituted by a calcined clay, metakaolin, is studied. We use rheological and ultrasonic reflection to monitor the evolution of the elastic properties of the paste with time, and light scattering to follow the change of its relaxation modes at small scales. We show that, at very early ages, of the order of hundreds
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Crack-healing ability of concrete enhanced by aerobic-anaerobic bacteria and fibers Cem. Concr. Res. (IF 10.9) Pub Date : 2024-06-13 Lu Jiang, Hua Xia, Sisi Hu, Xiangbi Zhao, Wenjing Wang, Yu Zhang, Zhu Li
In this study, the self-healing of cracks in four repair systems mixed by aerobic-anaerobic bacteria and fiber is studied. The results showed that specimens S-1, S-3, and S-4 demonstrate remarkable efficacy in achieving complete repair for the majority of cracks with widths of 0.6 mm or less within a healing period of 28 d. Conversely, cracks exceeding 0.45 mm in width in specimen S-2 present challenges
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Microstructure and microanalysis of portland cement pastes with high w/c ratios Cem. Concr. Res. (IF 10.9) Pub Date : 2024-06-13 Mahipal Kasaniya, Michael D.A. Thomas, Ted Moffatt, Ashlee Hossack
This study examines the influence of an increasing water-to-cement (w/c) ratio on the hydration mechanism of portland cement. Portland cement pastes at three w/c ratios of 0.5, 0.8 and 1.2 were prepared and cured in hermetically sealed vials at 40 °C for 14 days. Compressive strength, bulk electrical resistivity and bound water measurements were conducted. Thermogravimetric analysis was performed on
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Simulation of chloride diffusion tests in cement paste and mortar made with CEM II and CEM VI cements Cem. Concr. Res. (IF 10.9) Pub Date : 2024-06-13 Benoît Bary, Alisa Machner, Klaartje de Weerdt
We developed a simplified coupled model to simulate the chloride ingress of cement paste and mortar fabricated with CEM II/C-M (S-LL) and CEM VI (S-V) cements. Diffusion of chloride, calcium, sodium, potassium, sulphate and hydroxyl ions is considered, resulting in a set of coupled mass balance equations. Source and sink terms are introduced to represent the dissolution/precipitation processes due
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Different anomalies of two-stage water absorption in carbonated and non-carbonated cement-based materials Cem. Concr. Res. (IF 10.9) Pub Date : 2024-06-10 Zhidong Zhang, Ueli Angst
It was generally recognized that water absorption into cementitious materials shows two stages, the early stage with fast water uptake and the late stage with the reduced water absorption rate. Two types of anomalous moisture transport can be classified based on the shape of the water absorption curve. To investigate the main causes of different types of anomalous moisture transport, this study carried
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Biopolymer-assisted stable halloysite nanotubes dispersion in alkaline environment and their application in cementitious composite Cem. Concr. Res. (IF 10.9) Pub Date : 2024-06-08 Yaser Rashidi, Lily Li, Asghar Habibnejad Korayem
The colloidal dispersion of biopolymer-treated HNTs in the cementitious environment was studied. Three different biopolymer treatments, namely casein (C), guar gum (GG), and xanthan gum (XG), were utilized to prepare the stable colloidal dispersions of HNTs in such environments. The examination of the dispersion and time-dependent stability of untreated HNTs in a synthetic pore solution (SPS) revealed
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Morphological stability of multiple connected CSH sheets with a glue-like agent under aqueous conditions Cem. Concr. Res. (IF 10.9) Pub Date : 2024-06-08 Jiwei JIA, Ali Zaoui, W. Sekkal
Cement-based materials are strong yet brittle, organic modifications enhance their flexibility and durability, reducing cracks. The study investigates cementitious composites inspired by the “inorganic brick-and-organic mud” structure of nacre, focusing on organic modifications with Polyvinyl Alcohol (PVA) to enhance binding capacity and mechanical properties. Calculated Free energy and separation
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Role of partial limestone calcination in carbonated lime-based binders Cem. Concr. Res. (IF 10.9) Pub Date : 2024-06-06 Xiong Qian, Xinyu Zhou, Chuanlin Hu, Fazhou Wang, Shuguang Hu
Most carbonation reactions are characterized by products encasing unreacted particles, leading to incomplete reactions and consequently lower material utilization efficiency. This study introduces a novel approach for preparing gradient carbonated materials by partially calcined limestone (PCL), which is calcined below full calcination temperatures to maintain some original limestone while partially
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Electrochemical investigation of accelerated deterioration of concrete with iron-sulfide containing aggregates Cem. Concr. Res. (IF 10.9) Pub Date : 2024-06-04 Meshach Ojo, Donghyun Kim, Lesley Frame, Kay Wille
The present study advances the understanding of deterioration progress in concrete foundations containing iron-sulfide bearing aggregates through electrochemical accelerated testing, coupled with non-destructive damage evaluation. The method addresses the challenge of time constraints in conventional laboratory studies by expediting the iron-sulfide oxidation process and subsequent concrete deterioration
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Introducing Particle Shape Metric (PSM): A fundamental parameter that encapsulates role of aggregate shape in enhancing packing and performance Cem. Concr. Res. (IF 10.9) Pub Date : 2024-06-04 Bayezid Baten, Nishant Garg
Current packing models for aggregates are robust but they largely prioritize Particle Size Distributions (PSDs). There may be room for further improvement by incorporating aggregate shape. Here, we image up to 250 unique sand particles from 4 different sands and obtain key shape parameters such as Circularity (C), Roundness (R), and Aspect Ratio (AR). Combining these independent parameters, we introduce
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Influence of broad ion beam polishing on the surface roughness of hydrated cement paste and its implications on microstructural analysis Cem. Concr. Res. (IF 10.9) Pub Date : 2024-06-01 Thomas Sammer, Xiangyun Shi, Muhammad Zubair Khan, Aleksandar Matkovic, Christian Teichert, Johann G. Raith
In recent years, the technical capabilities of high-resolution Scanning Electron Microscopes (SEM) improved significantly. To fully utilise their potential, it is crucial that also the preparation techniques are advanced to obtain a high-quality surface which preserves even nanometre sized microstructural features. In this study, state-of-the-art resin-embedded polishing, and novel Broad Ion Beam (BIB)
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Properties of (Al, Fe)-ettringite solid solution: Experiment, atomic simulation, and thermodynamics modeling Cem. Concr. Res. (IF 10.9) Pub Date : 2024-05-30 Haoxuan Zhong, Lu Yang, Fazhou Wang
Ettringite (AFt) is critical to the durability and strength development of cement, and its structure and performance can be affected by the presence of chemical substitutions as well. Fe is one of the major constituents of cement, and its effect on the properties of AFt needs to be further understood. Combined density functional theory (DFT) with thermodynamics modeling, the crystal properties of Fe-bearing
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The influence of silicon on the formation and transformation of corrosion products Cem. Concr. Res. (IF 10.9) Pub Date : 2024-05-30 Fabio E. Furcas, Shishir Mundra, Barbara Lothenbach, Camelia N. Borca, Thomas Huthwelker, Ueli M. Angst
Accurate model predictions of corrosion-driven damage in reinforced concrete structures necessitate a comprehensive understanding of the rate of corrosion product formation. Here, we investigate the influence of dissolved Si characteristic of cementitious systems on the rate of corrosion product transformation at alkaline pH. Compared to systems aged in the absence of Si, small amounts of Si decrease
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Extrudability window and offline test methods to predict buildability of 3D printing concrete Cem. Concr. Res. (IF 10.9) Pub Date : 2024-05-30 Yu-cun Gu, Kamal H. Khayat
This study investigates the effect of thixotropy and stiffness evolution on the extrudability and buildability of 3D printing concrete. Different types of supplementary cementitious materials and limestone filler were used to prepare mortars with varying levels of thixotropy and early-age stiffness. Mixtures with yield stress and flocculation (τ) of 180–400 and 420–950 Pa, respectively, exhibited adequate
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Rheology, 3D printing, and particle interactions of xanthan gum-clay binder for earth concrete Cem. Concr. Res. (IF 10.9) Pub Date : 2024-05-30 Yierfan Maierdan, Diandian Zhao, Pooja Harsh Chokshi, Maria Garmonina, Shiho Kawashima
This study investigates the potential of xanthan gum (XG) to serve as a biopolymer binder for improving the rheological, mechanical, and 3D printing properties of earth-based concrete, aligning with the pressing need for sustainable, low-carbon construction materials. Experimental results indicate that XG could disperse kaolinite clay particles, which likely arises from the highly negative charges
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Active control of thixotropy of magneto-responsive cementitious materials with the intervention of time-varying magnetic fields Cem. Concr. Res. (IF 10.9) Pub Date : 2024-05-23 Yiyuan Zhang, Yaxin Tao, Yubo Sun, Kim Van Tittelboom, Yi Zhang, Karel Lesage, Geert De Schutter
The thixotropic behaviour of cementitious materials received widespread attention in recent years. However, structural break-down is often ignored in most research. The role of structural break-down in thixotropy of magneto-responsive cementitious materials should be discussed in order to achieve comprehensive active rheology control of cementitious materials, not only from more liquid-like to more
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Effect of wet carbonated recycled cement paste powder on the rheology of cement paste Cem. Concr. Res. (IF 10.9) Pub Date : 2024-05-23 Yuguang Mao, Sarra Drissi, Xiang Hu, Jian Zhang, Caijun Shi
This study investigated the effect of wet carbonated recycled cement paste powder (RCPP) on the rheological properties of cement pastes. The results showed that wet carbonated RCPP decreased the cement paste's setting time and flowability, increased its yield stress and plastic viscosity, and changed its thixotropy. The high absorption capacity of the silica gel in the carbonated RCPP was the most
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Further understanding of the sensitivity of triethanolamine on the hydration and setting performance of cement: Effect of aging Cem. Concr. Res. (IF 10.9) Pub Date : 2024-05-22 Zhiwei Liu, Zichen Lu, Liheng Zhang, Pengyu Chen, Zhenping Sun
After exposing cement under controlled relative humidity (RH) for different periods, impact of triethanolamine (TEA) on hydration and setting performance of aged cement was evaluated by Vicat test, calorimetry, XRD, and TGA. It is found anhydrite and hemihydrate can already transform to gypsum under 30 % RH, which leads to slight retardation on cement hydration. TEA accelerates the dissolution of sulfate
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Development of highly carbonation-effective calcium silicates (β-C2S): Phase evolution, microstructure, and carbonation mechanisms Cem. Concr. Res. (IF 10.9) Pub Date : 2024-05-21 Miao Ren, Peiliang Shen, Yong Tao, Chi-sun Poon
Carbonation of calcium silicate (CS) minerals to produce hardened construction materials has attracted increasing interest, but the efficiency of conventional CS minerals is low. This study prepared a highly reactive β-CS derived from a C-S-H precursor through hydrothermal synthesis. The potential CO uptake ability, product compositions, microstructural characteristics, and carbonation mechanisms of
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Surface chemistry and radionuclide anion immobilisation potential of phosphoric acid-activated metakaolin-based geopolymers Cem. Concr. Res. (IF 10.9) Pub Date : 2024-05-17 Xiaobo Niu, Yogarajah Elakneswaran, Naoki Hiroyoshi
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Cement hydration kinetics followed by electron spin resonance Cem. Concr. Res. (IF 10.9) Pub Date : 2024-05-17 Wolfgang Sauskojus, Christian Pritzel, Reinhard H.F. Trettin, Jörn Schmedt auf der Günne
Cement hydration is driven by a complex system of chemical reactions of several hydraulic binders and water that influence each other. Here we establish a method to measure the hydration kinetics of an individual clinker phase by electron spin resonance spectroscopy. The hydration of a Mn(II) doped crystalline phase can be analyzed from the decay of signals coming from the starting material and the
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A sweet answer to how sucrose delays tricalcium silicate hydration Cem. Concr. Res. (IF 10.9) Pub Date : 2024-05-17 Weiqing Xu, Deni Mance, Jean-Baptiste d'Espinose de Lacaillerie, Robert J. Flatt
The way in which chemical admixtures delay cement hydration is a highly debated topic in the cement related literature. Sugars in particular can cause substantial retardation and have been investigated by many researchers, but with conflicting conclusions.
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Structural features of thermally or mechano-chemically treated montmorillonite clays as precursors for alkali-activated cements production Cem. Concr. Res. (IF 10.9) Pub Date : 2024-05-16 Alastair T.M. Marsh, Sreejith Krishnan, Susan A. Bernal
In this study it was determined the impact of calcination or mechano-chemical activation (MCA) on the physico-chemical properties and reactivity of Ca-montmorillonite and Na-montmorillonite clays, and its subsequent effect on phase assemblage evolution of sodium hydroxide activated cements. MCA enabled colour control, enhanced early age reactivity of montmorillonite clays, associated with dehydroxylation
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Aggregate shape reconstruction and concrete mesostructure modelling based on the spherical DOG wavelet frame Cem. Concr. Res. (IF 10.9) Pub Date : 2024-05-16 Jingzhe Li, Huiling Sha, Binggen Zhan, Peng Gao, Qijun Yu, Yanbo Hu, Jingfeng Wang, Juan Wu
The reconstruction of multi-angled aggregates (e.g., manufactured aggregates) is increasingly concerned. Based on the compactly supported spherical “Difference of Gaussians” (DOG) wavelets, this paper proposed a novel shape reconstruction method (called the DOG method). In addition, this paper proposed a concrete mesostructure modelling method using the aggregates reconstructed by the DOG method. The
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D3 method: Direct and delayed dosing: New insights into specific surface area modification by superplasticizers Cem. Concr. Res. (IF 10.9) Pub Date : 2024-05-16 Shengnan Sha, Moghul Sirajuddin, Robert J. Flatt
In cement suspensions, a part of the superplasticizers measured as adsorbed by solution depletion, is actually consumed uselessly by intercalation, coprecipitation, micellization and/or modification of early hydrate surface area. This amount is often referred to as lost, as it is not effective as a dispersant. Despite extensive research on the subject, mechanisms responsible for this remain unclear
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Reply to the discussion of the paper ‘Low-field 1H NMR study on geopolymers: The effect of paramagnetic Fe(III)’ by C. Zhou, Z. Zhang and J. Qiao Cem. Concr. Res. (IF 10.9) Pub Date : 2024-05-16 Ziyou Yu, Rodrigo de Oliveira Silva, Yiannis Pontikes, Dimitrios Sakellariou
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New insight into the combined effect of aluminum sulfate and triethanolamine on cement hydration Cem. Concr. Res. (IF 10.9) Pub Date : 2024-05-14 Liheng Zhang, Zichen Lu, Yanrong Zhang, Zhiwei Liu, Ye Pan, Guoqing Zhang, Yan He, Zhenping Sun
The combined effect of aluminum sulfate (AS) and triethanolamine (TEA) on cement hydration was investigated by techniques of setting time, compressive strength, calorimetry, XRD, and ICP-OES. The results indicate that the increased strength through the addition of AS mainly originates from the accelerated silicate phase reaction. Besides, the combined addition of TEA and AS leads to an aggravated retardation
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An investigation into corrosion around voids at the steel-concrete interface Cem. Concr. Res. (IF 10.9) Pub Date : 2024-05-14 Miha Hren, Tadeja Kosec, Andraž Legat
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Temperature affected cement foaming and foams Cem. Concr. Res. (IF 10.9) Pub Date : 2024-05-14 Qiang Zeng, Shan Chen, Rijiao Yang, Zhendi Wang, Yang Zhao
This work reports the kinetics and structures of cement-limestone powder foams cast at the temperature between 27 and 42 °C. The pH, viscosity, flowability, temperature history and height of the slurries were measured, and the foaming kinetics was interpreted with the Weibull and Log-Logistic dose-time models. The structures and mechanical properties of the hardened foams were tested at 28 d. The results
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Thermodynamic modelling of alkali-silica reactions in blended cements Cem. Concr. Res. (IF 10.9) Pub Date : 2024-05-11 Haoliang Jin, Sam Ghazizadeh, John L. Provis
Experiments and field observations have shown that supplementary cementitious materials (SCMs) mitigate the risk of alkali-silica reaction (ASR) in Portland cement blends, but this is difficult to describe thermodynamically due to the lack of appropriate thermodynamic database information, and challenges in defining the kinetic factors. This paper examines how four well-known SCMs (namely ground granulated
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A discussion of the paper “Low-field [formula omitted]H NMR study on geopolymers: The effect of paramagnetic Fe(III)” by Z. Yu, R. de Oliveira-Silva, Y. Pontikes, and D. Sakellariou Cem. Concr. Res. (IF 10.9) Pub Date : 2024-05-08 Chunsheng Zhou, Zuhua Zhang, Jing Qiao
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Effect of natural and accelerated carbonation on microstructure and pH of sodium carbonate alkali-activated slag Cem. Concr. Res. (IF 10.9) Pub Date : 2024-05-08 Patrick Azar, Cédric Patapy, Gabriel Samson, François Cussigh, Laurent Frouin, Martin Cyr
This study aims to understand the effect of the natural and accelerated carbonation on the alkali-activated slag (AAS) activated by sodium carbonate. Carbonation increased AAS paste total porosity but reduced slag containing materials (CEM III) porosity. The pH after carbonation was higher in AAS than in CEM III, which was explained by the buffering effect of the alkalis and the carbonation of the
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Resilient crystalline admixture in ultra-high performance self-healing concrete under cyclic freeze-thaw with de-icing salts Cem. Concr. Res. (IF 10.9) Pub Date : 2024-05-08 Vanessa Cappellesso, Liberato Ferrara, Elke Gruyaert, Kim Van Tittelboom, Nele De Belie
Ultra-high performance (fibre-reinforced) concrete (UHPC) is recognised for its mechanical properties, such as tensile strain hardening, and exceptional durability, including autogenous healing capabilities due to, among others, the addition of supplementary cementitious materials and fibres. However, it is unknown how the cracked concrete can deal with freeze-thaw (FT) cycles with de-icing salts and
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Hydration in diluted solutions of brownmillerite extracted from SR cement and synthetic brownmillerite Cem. Concr. Res. (IF 10.9) Pub Date : 2024-05-07 Alexis Mériot, Sandrine Gauffinet, Marie-Noëlle de Noirfontaine, Mireille Courtial, Karen Alloncle, Laurent Izoret, Frédéric Dunstetter
The aim of this study is to investigate the reactivity of ferrites extracted from Sulfate Resisting (SR) Portland cement clinkers, until now often neglected. Industrial materials and synthetic materials have been studied and compared in the whole range of the Al/Fe ratio. Highly diluted aqueous suspensions were used, ranging between pure water and more complex solutions simulating the pore solution
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Sodium aluminate activated waste glass: Reduced efflorescence behavior by C(N)−A−S−H transformation Cem. Concr. Res. (IF 10.9) Pub Date : 2024-05-04 Tao Liu, Yuxuan Chen, Bo Yuan, Weitan Zhuang, H.J.H. Brouwers, Qingliang Yu
Waste glass has been highly used in alkali activated materials, but the efflorescence behavior remains an intractable issue. This study investigates the effect of sodium aluminate as an activator to activate waste glass with the aim to mitigate the efflorescence behavior, and blast furnace slag is used as calcium source as well as to promote the early age strength. The gel structure (reaction product)
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Modeling concrete deposition via 3D printing using reproducing kernel particle method Cem. Concr. Res. (IF 10.9) Pub Date : 2024-05-04 Hanbin Cheng, Aleksandra Radlińska, Michael Hillman, Feihong Liu, Jiarui Wang
The quality and geometry conformity of 3D concrete printing are the two major concerns facing autonomous construction. To investigate the geometry of printed concrete and optimize the printing strategy, the reproducing kernel particle method (RKPM) was developed and implemented for the first time to describe the flow of fresh concrete and simulate the process of 3D printing. The proposed novel numerical
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How does carbonation of alkali-activated slag and Portland cement systems impact steel corrosion differently? Cem. Concr. Res. (IF 10.9) Pub Date : 2024-05-03 Zushi Tian, Chuanqing Fu, Hailong Ye
Carbonation of cementitious materials, associated with neutralization of pore solution, is one of the prevalent reasons for inducing corrosion of steel in concrete. Compared with ordinary Portland cement (OPC) concrete, the poorer carbonation resistance of alkali-activated slag (AAS) concrete leads to serious durability concerns of a higher risk of steel corrosion. This work investigates the corrosion
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Atomic structure of nanocrystalline and amorphous ASR products Cem. Concr. Res. (IF 10.9) Pub Date : 2024-05-03 Tulio Honorio, Wang Wei
Limited information about the atomic structure of amorphous and nanocrystalline alkali–silica reaction (ASR) products is available. Here, reactive molecular simulations were employed to construct a model of these products based on defective shlykovite. To introduce disorder into the models, various annealing temperatures (ranging from ambient to temperatures above silicate dissolution) were tested
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A novel approach for the lifetime prediction and structural health monitoring of concrete sewer systems exposed to biogenic sulphide corrosion Cem. Concr. Res. (IF 10.9) Pub Date : 2024-05-03 R.A. Luimes, F.A.M. Rooyackers, A.S.J. Suiker, F.H.L.R. Clemens, E. Bosco
A novel, combined experimental-modelling approach is presented for the estimation of the corrosion depth, load bearing capacity and lifetime of unreinforced concrete sewer pipes exposed to prolonged biogenic sulphide corrosion. The biogenic sulphide corrosion process is mimicked through two types of representative chemical experiments, namely: (i) experiments performed under pH conditions, where dry-cast
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Degradation of alkali-activated Fe-rich slag in sulfuric acid Cem. Concr. Res. (IF 10.9) Pub Date : 2024-05-01 Nana Wen, Arne Peys, Tobias Hertel, Ziyou Yu, Dimitrios Sakellariou, Yiannis Pontikes
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Influence of free calcium sulfate levels on the early hydration of sulfate-rich belite sulfoaluminate clinkers: A comparative study with anhydrite and gypsum Cem. Concr. Res. (IF 10.9) Pub Date : 2024-04-29 Wensheng Zhang, Lixue Cao, Xuehong Ren, Jiayuan Ye, Lei Liu, Yanze Wu
In the present study, belite sulfoaluminate (BSA) clinkers containing varying levels of free calcium sulfate (f-CaSO)—specifically 0 %, 5 %, and 10 %—were synthesized. These clinkers were subsequently mixed with anhydrite and gypsum for comparative analysis. Utilizing a range of analytical techniques such as isothermal calorimetry, X-ray diffraction (XRD), and thermogravimetric analysis (TGA), the
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Factors influencing the hydration kinetics of ye'elimite; effect of free lime Cem. Concr. Res. (IF 10.9) Pub Date : 2024-04-27 Frank Bullerjahn, Maciej Zajac
This study investigates factors influencing the hydration of ye'elimite, comparing stoichiometric ye'elimite-rich clinkers with and without free lime (Y-C and Y, respectively). Although the hydration sequences and products were similar, there were notable differences in their kinetics. Y-C exhibited rapid hydration upon contact with water, followed by a significant slowdown within minutes. Contrary
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New insights into the immobilisation of Ce(IV) in Portland cement: Properties, hydration, microstructure and occurrence status of Ce Cem. Concr. Res. (IF 10.9) Pub Date : 2024-04-27 Haosen Ma, Yanjie Tang, Wei Chen, Qiu Li
The immobilisation mechanism of Pu(IV) by Portland cement-based material is not well understood. This study aims to reveal the immobilisation mechanism and occurrence status of Ce(IV) (chemical analogue of Pu(IV)) in Portland cement paste. The addition of Ce(NO) first slightly retarded then accelerated the early-age hydration of Portland cement, thereby resulting in an increase of compressive strength
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Can carbonation depth be measured in a nondestructive way? High-frequency quantitative ultrasound imaging for cement paste Cem. Concr. Res. (IF 10.9) Pub Date : 2024-04-25 Seungo Baek, Hyeong-Ki Kim, Michael L. Oelze, Gun Kim
Determining the carbonation depth is of paramount importance in assessing the durability of cementitious materials as the carbonation process alters their near-surface physicochemical properties. This paper introduces a novel quantitative ultrasound (QUS) technique capable of nondestructively identifying the carbonation depth, regardless of the tortuosity of the carbonation front. A 2.5 MHz phased
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Fundamental effects of using power ultrasound to accelerate C3S hydration Cem. Concr. Res. (IF 10.9) Pub Date : 2024-04-23 Ricardo Remus, Christiane Rößler, Simone Peters, Thomas Sowoidnich, Horst-Michael Ludwig
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Colloidal nanosilica promotes high-density calcium-silicate-hydrates in fine recycled concrete aggregate mortar Cem. Concr. Res. (IF 10.9) Pub Date : 2024-04-19 Nathanial Buettner, Gass Iyacu, Ange-Therese Akono
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Fast vapour migration next to a depressurizing interface: A possible driving mechanism of explosive spalling revealed by neutron imaging Cem. Concr. Res. (IF 10.9) Pub Date : 2024-04-17 Roberto Felicetti, Ramin Yarmohammadian, Stefano Dal Pont, Alessandro Tengattini
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Uptake of chloride and isosaccharinic acid by cement paste with high slag content (CEM III/C) Cem. Concr. Res. (IF 10.9) Pub Date : 2024-04-16 Yongheum Jo, Barbara Lothenbach, Neşe Çevirim-Papaioannou, Benny de Blochouse, Marcus Altmaier, Xavier Gaona
The uptake of chloride (Cl) and isosaccharinic acid (ISA, main degradation product of cellulose) by cement paste with high slag content (CEM III/C) was investigated with batch sorption experiments with Cl and inactive ISA. A weak uptake of chloride was quantified (0.43 ≤ R [L∙kg] ≤ 5.8), consistently with previous observations for Portland cement. C-S-H, AFm and hydrotalcite are suggested as primary
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Water-based graphene nanofluid additives: Advancements in sustainable, low-carbon, and high-performance nanocarbon-modified cementitious materials Cem. Concr. Res. (IF 10.9) Pub Date : 2024-04-16 Chun Pei, Si-cheng Kong, Ming-Zhi Guo, Ji-Hua Zhu
Advancing carbon neutrality in construction demands innovative, low-carbon, high-performance cement composites. This study introduces a water-stable graphene nanofluid admixture (GNA) at a 13 g/L concentration, addressing challenges in nanomaterial processing, dispersion, and cost for large-scale civil engineering. GNA can replace water in concrete casting, aligning with engineering practices. The
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Evolution of silicate species from waterglass in waterglass activated slag (WAS) pastes at early age Cem. Concr. Res. (IF 10.9) Pub Date : 2024-04-15 Dongdong Jiang, Zuhua Zhang, Caijun Shi
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Multiple cracking and strain-hardening criteria of Engineered Cementitious Composites (ECC) with river sand Cem. Concr. Res. (IF 10.9) Pub Date : 2024-04-13 Yazhao Li, Junxia Li, En-Hua Yang, Xinchun Guan
The inclusion of river sand in ECC alters the crack initiation and propagation behavior. As a result, the multiple cracking and pseudo strain-hardening of the river sand ECC (RS-ECC) are different from that of the typical micro-silica sand ECC. This study investigates the strain-hardening criteria for the RS-ECC by considering the matrix as a three-phase material containing pre-existing flaws along
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Combined effect of natural fibre and steel fibre on the thermal-mechanical properties of UHPC subjected to high temperature Cem. Concr. Res. (IF 10.9) Pub Date : 2024-04-13 Maha M.S. Ridha
This research investigates the combined effect of steel and natural fibre on the mechanical properties and spalling resistance of ultra-high performance concrete (UHPC) before and after exposure to elevated temperatures. The effects of two parameters, namely temperature (ambient temperature, 200 °C, 400 °C and 600 °C) and fibre type (solely macro end hooked steel fibre (MHS) and hybrid of micro straight
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A rheometric approach to assess plastic shrinkage and implications of early age drying on the microstructure of cement-based materials Cem. Concr. Res. (IF 10.9) Pub Date : 2024-04-12 Manu K. Mohan, A.V. Rahul, Yury Villagran-Zaccardi, Geert De Schutter, Kim Van Tittelboom
3D printed cementitious materials are subjected to environmental drying from a very early age as it does not have any formwork protection. In this paper, we present a novel methodology using a rheometer for measuring the shrinkage strains in such stiff cement-based materials from the onset of processing. In this approach, cylindrical samples are placed between parallel plates attached to the rheometer
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A microstructure-based model for quantifying irreversible yield stress evolution in cement-based pastes during hydration Cem. Concr. Res. (IF 10.9) Pub Date : 2024-04-11 Xiuliang Yin, Zhijun Wu, Lei Weng, Xiangyu Xu, Yuan Zhou, Quansheng Liu
Investigating workability loss in cement-based pastes during hydration, primarily marked by an irreversible yield stress increase, is crucial for cement-based materials application and development. This paper presents a model for quantifying the irreversible yield stress evolution by incorporating microstructural changes involving physical, chemical, and physicochemical effects. By systematically integrating