Cement and Concrete Research最新文献_第10页

On the action mechanism of phosphate-based superplasticizers in one-part alkali-activated slag 论磷酸盐系超塑化剂在单组分碱活性矿渣中的作用机理

IF 10.9 1区工程技术

Cement and Concrete Research Pub Date : 2024-09-06 DOI: 10.1016/j.cemconres.2024.107659

Shengnan Sha, Yuliang Wang, Hailong Ye

{"title":"On the action mechanism of phosphate-based superplasticizers in one-part alkali-activated slag","authors":"Shengnan Sha, Yuliang Wang, Hailong Ye","doi":"10.1016/j.cemconres.2024.107659","DOIUrl":"10.1016/j.cemconres.2024.107659","url":null,"abstract":"<div><p>The mechanisms responsible for the compromised or lost dispersing capability of polycarboxylate ether (PCE) superplasticizers in two-part alkali-activated slag (AAS) have been extensively studied, but limited scientific understanding is available on how PCEs function or lose their dispersing efficiency in one-part AAS systems, particularly those prepared using greener carbonate -based solid activators. This study investigates the dispersing and adsorption behaviors of phosphate-based PCE in one-part AAS activated by K<sub>2</sub>CO<sub>3</sub> or a combination of K<sub>2</sub>CO<sub>3</sub> and CaO. Our findings indicate that in K<sub>2</sub>CO<sub>3</sub>-activated slag systems, the loss of phosphate-based PCE efficiency primarily results from the conformational contraction of PCE molecules, which deteriorates steric repulsion in the alkaline activating solution, rather than the insolubility of PCEs in alkaline solution or competitive adsorption between PCEs and carbonate anions on dissolving slag grains. In K<sub>2</sub>CO<sub>3</sub>-CaO-activated slag systems, when PCE dosage is below 5 mg/g, the consumption of PCE by early precipitates (e.g., C-A-S-H, gaylussite, calcite) contributes substantially to its lost efficiency; however, once the PCE dosage surpasses this threshold, the dominant factor influencing PCE efficiency shifts to the conformational change of PCE.</p></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"186 ","pages":"Article 107659"},"PeriodicalIF":10.9,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142144061","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

Earth stabilisation with MgO-based cement 用氧化镁水泥稳定土质

IF 10.9 1区工程技术

Cement and Concrete Research Pub Date : 2024-09-05 DOI: 10.1016/j.cemconres.2024.107655

Ellina Bernard , Daniel Rentsch , Raphael Kuhn , Guillaume Habert , Pietro Lura

{"title":"Earth stabilisation with MgO-based cement","authors":"Ellina Bernard , Daniel Rentsch , Raphael Kuhn , Guillaume Habert , Pietro Lura","doi":"10.1016/j.cemconres.2024.107655","DOIUrl":"10.1016/j.cemconres.2024.107655","url":null,"abstract":"<div><p>This study compares, for the first time, MgO-based (MB) cement and Portland-based (PB) cement for stabilizing earth mortars. While MB and PB earth mortars reach similar strength, MB cement stabilization demonstrates superior early-age performance. Thermogravimetric analysis, X-ray diffraction, <sup>29</sup>Si and <sup>31</sup>P NMR spectroscopies show that the cement reacts in both systems and allow to establish the phase assemblages. The stabilized earth pastes contain less hydroxide phases, indicating a pozzolanic reaction in both cases.</p><p>MB-stabilized clay mortars retain about 1/3 of the compressive strength of pure MB mortar, while with PB this proportion is only 1/5. This difference demonstrates that MB is more compatible with clay minerals and more suitable for stabilizing earth mortars. If MB cement could be produced with renewable energy from CO<sub>2</sub>-free sources (instead of from magnesite), stabilization of earth mortars with MB would be substantially more CO<sub>2</sub> efficient than with PB.</p></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"186 ","pages":"Article 107655"},"PeriodicalIF":10.9,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0008884624002369/pdfft?md5=87c741b9ec94508b5517aef274ebc911&pid=1-s2.0-S0008884624002369-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142144049","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 novel method for precise determination of maximum particle loading fraction in highly concentrated suspensions 精确测定高浓度悬浮液中最大颗粒装载量的新方法

IF 10.9 1区工程技术

Cement and Concrete Research Pub Date : 2024-09-05 DOI: 10.1016/j.cemconres.2024.107658

Yongsok Seo

{"title":"A novel method for precise determination of maximum particle loading fraction in highly concentrated suspensions","authors":"Yongsok Seo","doi":"10.1016/j.cemconres.2024.107658","DOIUrl":"10.1016/j.cemconres.2024.107658","url":null,"abstract":"<div><h3>Hypothesis</h3><p>Accurately predicting the maximum particle loading fraction (ϕ<sub>max</sub>) of a suspension remains a significant challenge in both theoretical modeling and industrial applications.</p></div><div><h3>Experiments</h3><p>We present a novel method that surpasses existing approaches by precisely determining ϕ<sub>max</sub> through predicting the general suspension viscosity at a constant shear rate as a function of particle volume fraction. Our approach leverages boundary and initial conditions to pinpoint ϕ<sub>max</sub> with precision.</p></div><div><h3>Findings</h3><p>The proposed model flawlessly captures viscosity behavior across the entire range of volume fractions without pre-assumptions or limitations, showcasing its remarkable versatility. We validate the efficacy of our method by comparing its predictions with established theoretical models and diverse experimental data for various suspensions, including nanofluids and yield stress fluids, as reported in the literature. This extends to the evaluation of crucial parameters related to ϕ<sub>max</sub> within existing suspension viscosity models. Beyond its immediate applications, this approach opens avenues for exploring relationships between ϕ<sub>max</sub> and other suspension properties, potentially leading to broader advancements in understanding or manipulating suspension rheological behavior in material science.</p></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"186 ","pages":"Article 107658"},"PeriodicalIF":10.9,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142144051","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

Additive construction in practice – Realities of acceptance criteria 实践中的快速成型建筑 - 验收标准的现实性

IF 10.9 1区工程技术

Cement and Concrete Research Pub Date : 2024-09-04 DOI: 10.1016/j.cemconres.2024.107652

Megan Kreiger , Eric Kreiger , Stephan Mansour , Sean Monkman , Mohammad Aghajani Delavar , Petros Sideris , Casey Roberts , Matthew Friedell , Shawn Platt , Scott Jones

引用次数: 0

Digital fabrication with concrete beyond horizontal planar layers 超越水平平面层的混凝土数字化制造

IF 10.9 1区工程技术

Cement and Concrete Research Pub Date : 2024-09-04 DOI: 10.1016/j.cemconres.2024.107663

Dirk Lowke , Ana Anton , Richard Buswell , Selen Ercan Jenny , Robert J. Flatt , Ena Lloret Fritschi , Norman Hack , Inka Mai , Mariana Popescu , Harald Kloft

{"title":"Digital fabrication with concrete beyond horizontal planar layers","authors":"Dirk Lowke , Ana Anton , Richard Buswell , Selen Ercan Jenny , Robert J. Flatt , Ena Lloret Fritschi , Norman Hack , Inka Mai , Mariana Popescu , Harald Kloft","doi":"10.1016/j.cemconres.2024.107663","DOIUrl":"10.1016/j.cemconres.2024.107663","url":null,"abstract":"<div><p>Digital fabrication technologies, such as 3D concrete printing, are currently making their way into the construction industry. The primary focus in this field is often on the depositing processes, such as extrusion 3D concrete printing, where material is typically applied in horizontal planar layers. This area has seen substantial progress in recent years. However, numerous research and development projects are specifically targeting the additive manufacturing of unreinforced raw concrete components. When implementing these technologies in practice, it has become clear that additional processes, such as fully automated process-parallel reinforcement integration, application of cover layers and formative and subtractive post-processing of the components, are essential for successful application. In addition, by varying the orientation, characteristics and arrangement of the layers, new shapes and functions can be realised. Examples include angled layer orientation for producing vaulted geometries without support structures, as well as non-planar layer formation for complex component geometries or assembly joints. Moreover, alternative innovative manufacturing processes, such as KnitCrete, Smart Dynamic Casting or Injection 3D Printing, reveal new potential for the application of digital manufacturing technologies in the construction industry. This article aims to demonstrate the possibilities offered by digital fabrication with concrete beyond the stacking of horizontal planar layers, and how these technologies can complement and expand a future digital fabrication strategy in the construction industry.</p></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"186 ","pages":"Article 107663"},"PeriodicalIF":10.9,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0008884624002448/pdfft?md5=2650830d18d54487f981e33decdfc34c&pid=1-s2.0-S0008884624002448-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142136839","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

Unravelling the interplay between steel rebar corrosion rate and corrosion-induced cracking of reinforced concrete 揭示钢筋锈蚀率与钢筋混凝土锈蚀诱发开裂之间的相互作用

IF 10.9 1区工程技术

Cement and Concrete Research Pub Date : 2024-09-02 DOI: 10.1016/j.cemconres.2024.107647

Evžen Korec , Milan Jirásek , Hong S. Wong , Emilio Martínez-Pañeda

{"title":"Unravelling the interplay between steel rebar corrosion rate and corrosion-induced cracking of reinforced concrete","authors":"Evžen Korec , Milan Jirásek , Hong S. Wong , Emilio Martínez-Pañeda","doi":"10.1016/j.cemconres.2024.107647","DOIUrl":"10.1016/j.cemconres.2024.107647","url":null,"abstract":"<div><p>Accelerated impressed current testing is the most common experimental method for assessing the susceptibility to corrosion-induced cracking, the most prominent challenge to the durability of reinforced concrete structures. Although it is well known that accelerated impressed current tests lead to slower propagation of cracks (with respect to corrosion penetration) than in natural conditions, which results in overestimations of the delamination/spalling time, the origins of this phenomenon have puzzled researchers for more than a quarter of a century. In view of recent experimental findings, it is postulated that the phenomenon can be attributed to the variability of rust composition and density, specifically to the variable ratio of the mass fractions of iron oxide and iron hydroxide-oxide, which is affected by the magnitude of the applied corrosion current density. Based on this hypothesis, a corrosion-induced cracking model for virtual impressed-current testing is presented. The simulation results obtained with the proposed model are validated against experimental data, showing good agreement. Importantly, the model can predict corrosion-induced cracking under natural conditions and thus allows for the calculation of a newly proposed crack width slope correction factor, which extrapolates the surface crack width measured during accelerated impressed current tests to corrosion in natural conditions.</p></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"186 ","pages":"Article 107647"},"PeriodicalIF":10.9,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S000888462400228X/pdfft?md5=6745c12db290da40dee6943e961e33c5&pid=1-s2.0-S000888462400228X-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142122852","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

Carbonation reactivity of calcium silicate glasses at various calcium to silicate ratios and comparison with wollastonite 不同钙硅比硅酸钙玻璃的碳化反应性以及与硅灰石的比较

IF 10.9 1区工程技术

Cement and Concrete Research Pub Date : 2024-09-02 DOI: 10.1016/j.cemconres.2024.107653

Chen Li , Bo Liu , Qiaomu Zheng , Yi Li , Xinping Zhu , Yuan Fang , Qingxin Zhao , Zhengwu Jiang , Jiaqi Li

{"title":"Carbonation reactivity of calcium silicate glasses at various calcium to silicate ratios and comparison with wollastonite","authors":"Chen Li , Bo Liu , Qiaomu Zheng , Yi Li , Xinping Zhu , Yuan Fang , Qingxin Zhao , Zhengwu Jiang , Jiaqi Li","doi":"10.1016/j.cemconres.2024.107653","DOIUrl":"10.1016/j.cemconres.2024.107653","url":null,"abstract":"<div><p>Amorphous calcium (alumino) silicates are the main component of industrial byproducts (e.g., blast furnace slag and fly ash) and can be generated by grinding silicate minerals that are abundant in steel slag and carbonated calcium silicate binders. To promote the production of CO<sub>2</sub>-activated building material from diverse materials, this study investigated the carbonation of synthetic calcium silicate glasses, model compounds of these amorphous silicates. A dissolution-controlled carbonation mechanism was revealed, in contrast with a nucleation-controlled counterpart for the carbonation of wollastonite, a model compound of silicate minerals. The former mechanism is governed by the number of Q<sup>3</sup> species in the silica layers on carbonated particle surfaces serving as sites for ionic exchange. The latter is evidenced by well-aligned CaCO<sub>3</sub> nuclei precipitating on wollastonite particles under high CaCO<sub>3</sub> supersaturation. Overall, high Ca/Si ratios favor carbonation. At Ca/Si = 1, the calcium silicate glass shows faster carbonation kinetics than wollastonite at early ages.</p></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"186 ","pages":"Article 107653"},"PeriodicalIF":10.9,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142122853","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

Study on the solidification and hydration release behavior of K+ ions in high-potassium cement clinkers under different silica modulus 不同二氧化硅模量下高钾水泥熟料中 K+ 离子的凝固和水化释放行为研究

IF 10.9 1区工程技术

Cement and Concrete Research Pub Date : 2024-09-02 DOI: 10.1016/j.cemconres.2024.107661

Qingchun Yang, Jiaming Wu, Jun Jiang, Quanliang Li, Libo Yu, Xiaolei Lu, Jiayu Guo, Zhengmao Ye

{"title":"Study on the solidification and hydration release behavior of K+ ions in high-potassium cement clinkers under different silica modulus","authors":"Qingchun Yang, Jiaming Wu, Jun Jiang, Quanliang Li, Libo Yu, Xiaolei Lu, Jiayu Guo, Zhengmao Ye","doi":"10.1016/j.cemconres.2024.107661","DOIUrl":"10.1016/j.cemconres.2024.107661","url":null,"abstract":"<div><p>Recently, the widespread use of high‑potassium limestone has led to a sharp increase in the K<sub>2</sub>O content in clinker, resulting in high‑potassium cement clinker. When mixed with water, high‑potassium cement clinker releases a significant amount of K<sup>+</sup> ions in a short period, adversely affecting the performance of cement. Changes in the silica modulus can modify the proportion of silicate minerals and flux minerals that act as carriers of K<sup>+</sup> ions, which in turn affects the solidification and the hydration rate of K<sup>+</sup> ions. This study aims to investigate the influence of varying silica modulus in high‑potassium clinkers on the solid solution and hydration release rate of K<sup>+</sup> ions and its influences on the mineral composition and hydration performance of high‑potassium clinkers. The results indicate that an increase in silica modulus leads to a decrease in the solid solubility of K<sup>+</sup> ions in clinkers, resulting in a reduction in the ratio of C<sub>2</sub>S-α′<sub>L</sub>/C<sub>2</sub>S-β and the ratio of C<sub>3</sub>A-o/C<sub>3</sub>A-c. Additionally, an increase in the silica modulus delays the sulfate depletion peak, retards the release of K<sup>+</sup> ions, inhibits the transformation of AFt to Ms, and ultimately increases the compressive strength at 28 days.</p></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"186 ","pages":"Article 107661"},"PeriodicalIF":10.9,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142122854","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

Enhancement of the energy dissipation capacity C-S-H gel through self-crosslinking the poly (vinyl alcohol) 通过自交联聚乙烯醇提高 C-S-H 凝胶的能量耗散能力

IF 10.9 1区工程技术

Cement and Concrete Research Pub Date : 2024-09-01 DOI: 10.1016/j.cemconres.2024.107648

Huasheng Zhu , Xuli Lan , Xiaohui Zeng , Guangcheng Long , Youjun Xie

{"title":"Enhancement of the energy dissipation capacity C-S-H gel through self-crosslinking the poly (vinyl alcohol)","authors":"Huasheng Zhu , Xuli Lan , Xiaohui Zeng , Guangcheng Long , Youjun Xie","doi":"10.1016/j.cemconres.2024.107648","DOIUrl":"10.1016/j.cemconres.2024.107648","url":null,"abstract":"<div><p>Damping cementitious materials have been widely used in engineering structures for vibration control. However, achieving a balance between the mechanical strength and damping capacity of cementitious materials remains a challenge. Herein, we utilized an initiator (APS) to initiate the self-crosslinking reaction of PVA molecules in C<sub>3</sub>S paste, then successfully introduced the viscoelastic PVA membranes into C-S-H gel to enhance its energy dissipation capacity. Results showed that the self-crosslinking PVA (scPVA) increased the loss modulus (<span><math><msup><mi>E</mi><mrow><mo>′</mo><mo>′</mo></mrow></msup></math></span>) of C-S-H gel by about 158 %, increased loss tangent (<span><math><mo>tan</mo><mi>δ</mi></math></span>) by 85 % and increased the compressive strength by 24 %. Nano-microscopic tests and molecular dynamics (MD) simulation confirmed that scPVA was introduced into C-S-H gel via the hydrogen-bonding interaction, and then formed the viscoelastic PVA membranes, which promoted C<sub>3</sub>S hydration, reduced the pore size of C-S-H gel and increased the mean chain length (MCL) of C-S-H gel. This study proposes a novel approach for designing high-damping cementitious materials.</p></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"185 ","pages":"Article 107648"},"PeriodicalIF":10.9,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142117422","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

Fluid transport in Ordinary Portland cement and slag cement from in-situ positron emission tomography 通过原位正电子发射断层扫描观察普通硅酸盐水泥和矿渣水泥中的流体输送情况

IF 10.9 1区工程技术

Cement and Concrete Research Pub Date : 2024-08-29 DOI: 10.1016/j.cemconres.2024.107657

Amit G. Reiss , Johannes Kulenkampff , Gabriela Bar-Nes , Cornelius Fischer , Simon Emmanuel

引用次数: 0