Cement and Concrete Research最新文献_第3页

Rate effect on the pull-out load of individual fibers in concrete: A probabilistic modeling approach

IF 10.9 1区工程技术

Cement and Concrete Research Pub Date : 2025-03-11 DOI: 10.1016/j.cemconres.2025.107857

Takeru Kanazawa , John E. Bolander

{"title":"Rate effect on the pull-out load of individual fibers in concrete: A probabilistic modeling approach","authors":"Takeru Kanazawa , John E. Bolander","doi":"10.1016/j.cemconres.2025.107857","DOIUrl":"10.1016/j.cemconres.2025.107857","url":null,"abstract":"<div><div>Understanding of the load-rate dependence of fiber pull-out from concrete has been hindered by the large scatter of test data. Relatively little attention has been given to the statistical nature of single-fiber pull-out under different loading rates. The present study is based on a probabilistic interpretation of the pull-out phenomenon, assessing the statistical fluctuations observed in the common finding that complete pull-out occurs at greater load levels under higher loading rates. Since progressive debonding along the fiber–matrix interface affects the pull-out behavior, interfacial crack growth is modeled using a fracture mechanics approach. Based on a theoretical justification, the transition probability to debonding is devised and implemented within a Markov chain model. The Markov model accounts for debonding propagation with each stress increment until complete pull-out. The results demonstrate that the probability distributions of stress at complete pull-out differ from a normal distribution. The coefficient of variation is also independent of the loading rates. These findings show reasonable agreement with statistical variations observed from test data.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"193 ","pages":"Article 107857"},"PeriodicalIF":10.9,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143590118","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}

引用次数: 0

High energy X-ray scattering reveals the short-range order of proto-C-S-H: Implications for the nucleation of cement hydrates

IF 10.9 1区工程技术

Cement and Concrete Research Pub Date : 2025-03-10 DOI: 10.1016/j.cemconres.2025.107855

R. Besselink , A. Poulain , M. la Bella , A.-L. Auzende , S. Goberna-Ferron , M.P. Asta , V. Magnin , S. Bureau , L. Fernández-Carrasco , A.E.S. Van Driessche , A. Fernandez-Martinez

{"title":"High energy X-ray scattering reveals the short-range order of proto-C-S-H: Implications for the nucleation of cement hydrates","authors":"R. Besselink , A. Poulain , M. la Bella , A.-L. Auzende , S. Goberna-Ferron , M.P. Asta , V. Magnin , S. Bureau , L. Fernández-Carrasco , A.E.S. Van Driessche , A. Fernandez-Martinez","doi":"10.1016/j.cemconres.2025.107855","DOIUrl":"10.1016/j.cemconres.2025.107855","url":null,"abstract":"<div><div>The heterogeneous nature of the cement clinker, its complex coupled dissolution/re-precipitation process and the complex defect chemistry of the hydrates formed during cement hydration, make that the nucleation and growth mechanisms of cement hydrates are not fully understood. Recent studies have suggested the existence of a disordered precursor prior to the crystallization of C-S-H. Here, a combination of X-ray scattering and electron microscopy experiments are used to study the structure and crystallization kinetics of this amorphous intermediate. Our results suggest that proto-C-S-H is predominantly composed of 6-fold oxygen-to-calcium coordinated CaO<sub>x</sub> polyhedra, in contrast to the 7-fold coordinated polyhedra in C-S-H with a tobermorite-like structure. The addition of gluconate, a widely used additive, resulted in an increased kinetic persistence of proto-C-S-H. Overall, our study provides new insights into the formation and structure of proto-C-S-H, and suggests that it plays an important role in the crystallization mechanism of C-S-H.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"193 ","pages":"Article 107855"},"PeriodicalIF":10.9,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143590050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Pb-induced retardation of early hydration of Portland cement: Insights from in-situ XRD and implications for substitution with industrial by-products

IF 10.9 1区工程技术

Cement and Concrete Research Pub Date : 2025-03-09 DOI: 10.1016/j.cemconres.2025.107867

Yikai Liu , Maria Chiara Dalconi , Maurizio Pietro Bellotto , Luca Valentini , Simone Molinari , Xinyi Yuan , Daolin Wang , Wei Hu , Qiusong Chen , Alejandro Fernandez-Martinez , Gilberto Artioli

{"title":"Pb-induced retardation of early hydration of Portland cement: Insights from in-situ XRD and implications for substitution with industrial by-products","authors":"Yikai Liu , Maria Chiara Dalconi , Maurizio Pietro Bellotto , Luca Valentini , Simone Molinari , Xinyi Yuan , Daolin Wang , Wei Hu , Qiusong Chen , Alejandro Fernandez-Martinez , Gilberto Artioli","doi":"10.1016/j.cemconres.2025.107867","DOIUrl":"10.1016/j.cemconres.2025.107867","url":null,"abstract":"<div><div>Using industrial by-products as substitutes for Ordinary Portland Cement (OPC) is a promising strategy to reduce its environmental impact. However, heavy metals like Pb strongly interfere with initial kinetics. The dynamic physicochemical environment makes it challenging to identify the key factors. Here, we employed <em>in-situ</em> XRD as a time-dependent method, alongside conventional characterization techniques and geochemical modeling, to investigate the Pb-induced retardation in CEMI 42.5R and 52.5R. The results show that Pb-hydroxides and Pb-O-Si clusters are expected to be the primary mechanisms for this inhibition. Among clinker phases, C<sub>3</sub>A dissolution is less affected and serves as the primary source of alkalinity in early hydration, promoting hydration products precipitation and gypsum dissolution. Geochemical modeling suggests that Pb species concentration in the solution regulates the precipitation of hydration products, especially portlandite. The comparison of hydration kinetics of 2 types of OPC highlights optimizing particle size as a solution to mitigate retardation impact.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"193 ","pages":"Article 107867"},"PeriodicalIF":10.9,"publicationDate":"2025-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143576380","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A preliminary study on an effective and simplistic self-healing concept for cement using coarse clinker particles as the healing agent

IF 10.9 1区工程技术

Cement and Concrete Research Pub Date : 2025-03-05 DOI: 10.1016/j.cemconres.2025.107859

Jialiang Wang, Min Wu

{"title":"A preliminary study on an effective and simplistic self-healing concept for cement using coarse clinker particles as the healing agent","authors":"Jialiang Wang, Min Wu","doi":"10.1016/j.cemconres.2025.107859","DOIUrl":"10.1016/j.cemconres.2025.107859","url":null,"abstract":"<div><div>Effective, low-cost and simplistic self-healing strategies for cement-based systems are attractive. This work proposed a concept where coarse clinker particles were used to replace cement and acted as the healing agent, and the effectiveness was validated by comprehensive studies. The results showed the high potential of the clinker sizes (40–60 μm, 60–90 μm, 0.5–1 mm) and replacement ratios (20–40%) under the studied conditions. For the clinker sized 40–60 μm, the 28d tensile and compressive strength recovery rates achieved 1.12 and 0.91, and the 56d crack sealing width and area reached 300–400 μm and 83.4%–94.4%, which even exceeds conventional autonomous self-healing strategies. The microscopic analyses indicated that larger clinker particles affected reaction kinetics of hydrating particles and improved spatial distribution of the hydration products. By retaining abundant unhdyrated parts and leading to more uniform distribution of the hydration products, the coarse clinker particles significantly improved self-healing properties of the cement mixes.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"193 ","pages":"Article 107859"},"PeriodicalIF":10.9,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143546521","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

From bauxite residue mineralogy to reactivity and properties of blended cements 从铝矾土残渣矿物学到混合水泥的反应性和特性

IF 10.9 1区工程技术

Cement and Concrete Research Pub Date : 2025-03-03 DOI: 10.1016/j.cemconres.2025.107854

Michael Wenzel, Fabien Georget, Thomas Matschei

引用次数: 0

Mechanisms governing in-depth infiltration of crack filling solutions in concrete using a magnetic approach

IF 10.9 1区工程技术

Cement and Concrete Research Pub Date : 2025-03-01 DOI: 10.1016/j.cemconres.2025.107856

Onur Ozturk, Sriramya Duddukuri Nair

引用次数: 0

Freezing behavior of ionic solutions within calcium silicate hydrate gel pores

IF 10.9 1区工程技术

Cement and Concrete Research Pub Date : 2025-03-01 DOI: 10.1016/j.cemconres.2025.107841

Songyue Chai , Jianyu Song , Muhan Wang , Yue Zhang , Bo-Tao Huang , Bing Yin , Pan Wang , Dongshuai Hou

{"title":"Freezing behavior of ionic solutions within calcium silicate hydrate gel pores","authors":"Songyue Chai , Jianyu Song , Muhan Wang , Yue Zhang , Bo-Tao Huang , Bing Yin , Pan Wang , Dongshuai Hou","doi":"10.1016/j.cemconres.2025.107841","DOIUrl":"10.1016/j.cemconres.2025.107841","url":null,"abstract":"<div><div>Salt-frost damage is a crucial issue affecting the durability of concrete structures, however, the freezing behavior and micro-mechanisms of ionic solutions within cementitious material gel pores remain unclear, which is not conducive to optimizing cold-resistant concrete design from the bottom up. In this study, the models of saturated calcium silicate hydrate (C-S-H) gel pores containing NaCl, Na<sub>2</sub>SO<sub>4</sub>, and aqueous solution, respectively, were constructed by molecular dynamics (MD) simulation. We investigated the freezing behavior of ionic solutions within the gel pores at 230 K. The freezing process of models exhibited a distinct periodic pattern. Na<sup>+</sup> and Cl<sup>−</sup> delayed the freezing of pore water, while <span><math><msubsup><mi>SO</mi><mn>4</mn><mrow><mn>2</mn><mo>−</mo></mrow></msubsup></math></span> accumulated near the freezing front, significantly hindering freezing progression. The freezing resulted in two types of nano brine pockets in the NaCl model. This work provides new molecular insights into salt freezing in cementitious materials and informs the design of cold-resistant concrete at the molecular scale.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"192 ","pages":"Article 107841"},"PeriodicalIF":10.9,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143518892","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}

引用次数: 0

Effects of nano- and micro-cellulose on Ca(OH)2 formation: Implications for lime-based binders

IF 10.9 1区工程技术

Cement and Concrete Research Pub Date : 2025-02-27 DOI: 10.1016/j.cemconres.2025.107851

Paulina Guzmán García Lascurain , Carlos Rodriguez-Navarro , Lucia Toniolo , Sara Goidanich

{"title":"Effects of nano- and micro-cellulose on Ca(OH)2 formation: Implications for lime-based binders","authors":"Paulina Guzmán García Lascurain , Carlos Rodriguez-Navarro , Lucia Toniolo , Sara Goidanich","doi":"10.1016/j.cemconres.2025.107851","DOIUrl":"10.1016/j.cemconres.2025.107851","url":null,"abstract":"<div><div>Air lime-based mortars and plasters are preferred for the restoration of historic masonry due to their high compatibility, and for modern constructions given their lower environmental impact. However, their slow setting (via carbonation) and their limited strength hinder their widespread use. This study explores the influence of nano- and micro-cellulose additives dosed during lime slaking on the formation and textural/structural features of calcium hydroxide. The alkaline degradation of the additives, along with their interaction and adsorption/occlusion during heterogeneous and homogeneous precipitation of calcium hydroxide was studied. Both additives foster the non-classical crystallization of portlandite via amorphous phases, resulting in plate-like crystals in the case of nano-cellulose, whereas more reactive micro-cellulose promotes the stabilization of a dense liquid precursor, and upon its dehydration, the stabilization of amorphous calcium hydroxide. Ultimately both additives lead to the formation of potentially more reactive nano and mesostructured Ca(OH)<sub>2</sub> particles.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"192 ","pages":"Article 107851"},"PeriodicalIF":10.9,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143509904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Water's grip on CO2 intake in mesopores of dicalcium silicate

IF 10.9 1区工程技术

Cement and Concrete Research Pub Date : 2025-02-26 DOI: 10.1016/j.cemconres.2025.107842

Gen Li , Yong Tao , Yining Gao , Peiliang Shen , Xiong Qian , Binbin Yin , Roland J.-M. Pellenq , Chi Sun Poon

{"title":"Water's grip on CO2 intake in mesopores of dicalcium silicate","authors":"Gen Li , Yong Tao , Yining Gao , Peiliang Shen , Xiong Qian , Binbin Yin , Roland J.-M. Pellenq , Chi Sun Poon","doi":"10.1016/j.cemconres.2025.107842","DOIUrl":"10.1016/j.cemconres.2025.107842","url":null,"abstract":"<div><div>While carbon sequestration with dicalcium silicate (C<sub>2</sub>S) offers a promising approach, the underlying mechanisms governing the contrasting carbonation efficiencies of different polymorphs remain poorly understood. Taking three C<sub>2</sub>S polymorphs as a paradigm, this study uses Grand Canonical Monte Carlo simulations to investigate CO<sub>2</sub> physisorption within α<sub>L</sub>-, β-, and γ-C<sub>2</sub>S mesopores under dry, unhydrated, and hydrated conditions. Our findings show that in dry scenarios, solid-gas interactions dominate, with γ-C<sub>2</sub>S exhibiting the lowest CO<sub>2</sub> intake due to its high surface charge density. A nanometer-thick water film in humid environments significantly enhances CO<sub>2</sub> adsorption due to the liquid-gas interactions, which are mediated by surface charges via the polarization of water molecules. Surface hydroxylation increases surface charge density in hydrated α<sub>L</sub>- and β-C<sub>2</sub>S and reduces their CO<sub>2</sub> adsorption capacity. The slower hydration of γ-C<sub>2</sub>S leads to a comparatively higher CO<sub>2</sub> adsorption capacity, suggesting a larger CO<sub>2</sub> reservoir within its mesopores. This enhanced CO<sub>2</sub> availability potentially explains the experimentally observed superior carbonation efficiency of γ-C<sub>2</sub>S and demonstrates a vivid example of the competing effect of hydration and carbonation for cement minerals. These molecular-level insights provide a profound understanding of the complex interplay between surface properties, hydration, and CO<sub>2</sub> physisorption in the carbonation of C<sub>2</sub>S and other carbonatable materials.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"192 ","pages":"Article 107842"},"PeriodicalIF":10.9,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143488500","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}

引用次数: 0

Effect of aluminum dihydrogen phosphate in enhancing mechanical properties and water resistance of magnesium phosphate cement

IF 10.9 1区工程技术

Cement and Concrete Research Pub Date : 2025-02-24 DOI: 10.1016/j.cemconres.2025.107849

Xingyu Gan , Haiming Zhang , Zeyu Lu , Kai Ma , Xiaowen Chen , Lingchao Lu , Laibo Li

{"title":"Effect of aluminum dihydrogen phosphate in enhancing mechanical properties and water resistance of magnesium phosphate cement","authors":"Xingyu Gan , Haiming Zhang , Zeyu Lu , Kai Ma , Xiaowen Chen , Lingchao Lu , Laibo Li","doi":"10.1016/j.cemconres.2025.107849","DOIUrl":"10.1016/j.cemconres.2025.107849","url":null,"abstract":"<div><div>Incorporating aluminum dihydrogen phosphate into magnesium phosphate cement (MPC), including magnesium ammonium phosphate cement (AMAPC) and magnesium potassium phosphate cement (AMKPC), significantly enhances both compressive strength and water resistance. The results show that AMAPC-3 exhibited a remarkable increase in compressive strength, maintaining a compressive strength retention ratio of 0.83 after 60 days. The addition of aluminum dihydrogen phosphate introduced extra phosphate ions that facilitated the hydration of unreacted MgO, resulting in an increased formation of hydration products such as struvite and k-struvite. Furthermore, it participated in independent hydration reactions, generating new phase Al(OH)<sub>3</sub> gel and Al(PO<sub>4</sub>)·2H<sub>2</sub>O gel, which contributed to a denser microstructure. Microstructural analysis confirmed a refined pore structure and reduced porosity in the modified cements. These findings position aluminum dihydrogen phosphate as an effective modifier for enhancing the water resistance and mechanical properties of MPCs.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"192 ","pages":"Article 107849"},"PeriodicalIF":10.9,"publicationDate":"2025-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143479782","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}

引用次数: 0