Cement and Concrete Research最新文献_第10页

Aluminate 2K systems in digital concrete: Process, design, chemistry, and outlook 数字混凝土中的铝酸盐 2K 系统：工艺、设计、化学和展望

IF 10.9 1区工程技术

Cement and Concrete Research Pub Date : 2024-08-20 DOI: 10.1016/j.cemconres.2024.107644

Timothy Wangler, Yaxin Tao, Arnesh Das, Matineh Mahmoudi, Seyma Gürel, Robert J. Flatt

{"title":"Aluminate 2K systems in digital concrete: Process, design, chemistry, and outlook","authors":"Timothy Wangler, Yaxin Tao, Arnesh Das, Matineh Mahmoudi, Seyma Gürel, Robert J. Flatt","doi":"10.1016/j.cemconres.2024.107644","DOIUrl":"10.1016/j.cemconres.2024.107644","url":null,"abstract":"<div><p>Digital concrete is advancing due to growing economic incentives for construction automation. Achieving more sustainable concrete construction requires carbon reduction, and digital concrete technologies enable material-saving designs. By decoupling production strength from design strength, two-component (2K) systems utilizing aluminate precipitation offer the most flexibility, allowing more sustainable mixes with higher substitution levels. However, 2K aluminate systems are complex and demand a deeper understanding of their chemistry and strength buildup. This article reviews the basics of 2K aluminate systems, specifically aluminum sulfate-based and calcium aluminate cement/calcium sulfate-based systems, and their use in an inline active mixing reactor. An example reaction engineering analysis predicts the degree of reaction in a given reactor design, relating it to yield stress. The two chemical systems are compared, and future research recommendations are provided.</p></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"185 ","pages":"Article 107644"},"PeriodicalIF":10.9,"publicationDate":"2024-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0008884624002254/pdfft?md5=7edb6b540bd4f2463218e3f65dc3569e&pid=1-s2.0-S0008884624002254-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142011753","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

Cationic-ratio-regulated surface chloride adsorption of layered double hydroxides 受阳离子比例调节的层状双氢氧化物表面氯化物吸附现象

IF 10.9 1区工程技术

Cement and Concrete Research Pub Date : 2024-08-13 DOI: 10.1016/j.cemconres.2024.107643

Qinglu Yu , Xing Ming , Peixian Huo , Guoxing Sun

{"title":"Cationic-ratio-regulated surface chloride adsorption of layered double hydroxides","authors":"Qinglu Yu , Xing Ming , Peixian Huo , Guoxing Sun","doi":"10.1016/j.cemconres.2024.107643","DOIUrl":"10.1016/j.cemconres.2024.107643","url":null,"abstract":"<div><p>Layered double hydroxides (LDHs) have emerged as an effective ingredient for enhancing the durability of cement-based materials against chloride-contaminated coastal or marine environments. Yet, the relationship between the surface chemistry and consequential adsorption affinity, which mainly constitutes chloride binding capacity of LDHs, still remain elusive, especially in alkaline cement pore solutions. Herein, we investigate Mg-Al-CO<sub>3</sub>-LDHs to demonstrate the cationic-ratio- (M<sup>II</sup>/M<sup>III</sup>-) regulated surface chloride adsorption in alkaline solutions through a series of progressively in-depth means. The regulatory mechanism of the cationic ratio is microscopically operated through diverse composition and proportion of hydroxylated clusters with varying deprotonation reactivity of bonded hydroxyl on the surface. DFT calculations combined with multiple surface characterization techniques indicate that the varying reactivity is determined by the ionic bonding characteristics of H<img>O bond and the electrostatic attraction ability of different clusters. The LDH with Mg/Al ratio of 2.0 exhibits the optimal surface chloride adsorption among ratios ranging from 1.6 to 3.8 in alkaline solutions due to the strong resistance to nucleophilic attack from OH<sup>−</sup> of Mg<sub>2</sub>Al-OH cluster while maintaining high electrostatic attraction ability. Our findings advance the comprehension of surface interactions of LDHs with alkaline environments while underscoring the role of cationic ratio in surface chloride adsorption.</p></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"185 ","pages":"Article 107643"},"PeriodicalIF":10.9,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141979009","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 alkali-hydroxide on hydration kinetics and microstructure of high-volume fly ash blended cement pastes 碱氢氧化物对高掺量粉煤灰水泥浆水化动力学和微观结构的影响

IF 10.9 1区工程技术

Cement and Concrete Research Pub Date : 2024-08-12 DOI: 10.1016/j.cemconres.2024.107641

Muhammad Riaz Ahmad , Satya Medepalli , Tiao Wang , Jian-Guo Dai , Yuqian Zheng , Tetsuya Ishida

{"title":"Effect of alkali-hydroxide on hydration kinetics and microstructure of high-volume fly ash blended cement pastes","authors":"Muhammad Riaz Ahmad , Satya Medepalli , Tiao Wang , Jian-Guo Dai , Yuqian Zheng , Tetsuya Ishida","doi":"10.1016/j.cemconres.2024.107641","DOIUrl":"10.1016/j.cemconres.2024.107641","url":null,"abstract":"<div><p>The influence of NaOH on pore structure, reaction kinetics, volume, and morphology of reaction products in high-volume-fly-ash mixtures was explored by two mixing methods: (i) direct addition of 0.2 M, 0.5 M and 1.0 M NaOH solution into cement-FA powder, and (ii) pre-dissolving FA into NaOH solution before mixing with cement. The pre-dissolution technique improved early-age mechanical performance by enhancing Si release, aiding the expedited precipitation of extra C-A-S-H gel. Both methods improved the degree of FA reaction and alite/belite hydration. However, 1.0 M NaOH negatively affected the strength and microstructure properties due to undesirable silica-gel formation, C-A-S-H gel carbonation, and increased capillary pore volume. NaOH concentration has affected the packing density of C-A-S-H gel, where high-pH systems exhibit loosely packed sheet-like clusters. Ca/Si of C-A-S-H gel in low and high pH systems evolved with increased curing age, with low pH system exhibiting high Ca/Si at 90 days.</p></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"185 ","pages":"Article 107641"},"PeriodicalIF":10.9,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141979008","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

X-ray near-field ptychographic nanoimaging of cement pastes 水泥浆的 X 射线近场层析纳米成像

IF 10.9 1区工程技术

Cement and Concrete Research Pub Date : 2024-08-11 DOI: 10.1016/j.cemconres.2024.107622

Shiva Shirani , Ana Cuesta , Isabel Santacruz , Angeles G. De la Torre , Ana Diaz , Pavel Trtik , Mirko Holler , Miguel A.G. Aranda

{"title":"X-ray near-field ptychographic nanoimaging of cement pastes","authors":"Shiva Shirani , Ana Cuesta , Isabel Santacruz , Angeles G. De la Torre , Ana Diaz , Pavel Trtik , Mirko Holler , Miguel A.G. Aranda","doi":"10.1016/j.cemconres.2024.107622","DOIUrl":"10.1016/j.cemconres.2024.107622","url":null,"abstract":"<div><p>The hydration processes of Portland cements (PC) and blends are complicated as there are many components with great heterogeneity at different length scales. Thus, 3D nanoimaging techniques with high spatial resolution and scanning large fields of view are needed. Here, synchrotron X-ray near-field ptychographic tomography is used to investigate four pastes within 0.2 mm thick capillaries: PC with CaCl<sub>2</sub>, PC hydration enhanced by C-S-H nucleation seeding, PC partly substituted with metakaolin, and PC partly substituted with metakaolin and limestone. Data analysis emphasis has been placed on the characterization of amorphous components: (i) C-S-H and C-A-S-H gels; (ii) iron aluminium siliceous hydrogarnets; (iii) metakaolin; and (iv) aluminium carboaluminate, AFm-like. Synchrotron ptychotomography yields electron density and absorption coefficient tomograms and the resulting bivariate plots are instrumental for characterising these amorphous components. The attained spatial resolution, ∼220 nm, with very good contrast allowed us to determine nanofeatures including mass densities and spatial distributions of amorphous components. For instance, the C-S-H gel mass density differences between the two type of accelerated pastes are detailed.</p></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"185 ","pages":"Article 107622"},"PeriodicalIF":10.9,"publicationDate":"2024-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0008884624002035/pdfft?md5=c749e0e47514b2597a3639f25b6df6d4&pid=1-s2.0-S0008884624002035-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141954149","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

Spatial variability analysis of aged bridge concrete interfacial transition zone using 3D image scanning 利用三维图像扫描对老化桥梁混凝土界面过渡区进行空间变化分析

IF 10.9 1区工程技术

Cement and Concrete Research Pub Date : 2024-08-07 DOI: 10.1016/j.cemconres.2024.107621

Hongtao Cui, Zhonglong Li, Xu Zhang, Yapeng Guo, Shunlong Li

引用次数: 0

Drying-induced damages in exposed fresh cement-based materials at very early ages: From standard casting to 3D printing 暴露的新鲜水泥基材料在很早的龄期就会出现干燥引起的损坏：从标准铸造到 3D 打印

IF 10.9 1区工程技术

Cement and Concrete Research Pub Date : 2024-08-06 DOI: 10.1016/j.cemconres.2024.107614

Wenqiang Zuo , Laura Caneda-Martinez , Emmanuel Keita , Patrick Aimedieu , Michel Bornert , Nicolas Roussel

引用次数: 0

Fracture toughness of cement paste constituents assessed by micro-scratching correlated with acoustic emission 通过与声发射相关的微划痕评估水泥浆成分的断裂韧性

IF 10.9 1区工程技术

Cement and Concrete Research Pub Date : 2024-08-06 DOI: 10.1016/j.cemconres.2024.107623

Jiří Němeček , Radim Čtvrtlík , Lukáš Václavek , Jiří Němeček

{"title":"Fracture toughness of cement paste constituents assessed by micro-scratching correlated with acoustic emission","authors":"Jiří Němeček , Radim Čtvrtlík , Lukáš Václavek , Jiří Němeček","doi":"10.1016/j.cemconres.2024.107623","DOIUrl":"10.1016/j.cemconres.2024.107623","url":null,"abstract":"<div><p>The fracture toughness of cement paste is difficult to quantify both by standard nanoindentation tests and by time-consuming and expensive measurements on micro-specimens milled with a focused ion beam. Here, a well-calibrated scratch test with simultaneous recording of acoustic emission signals was used to quickly and easily provide statistically relevant quantitative results for a wide range of scales (1–100 µm). The microscale fracture toughness for the main hydration products reached 0.54 ± 0.03 MPa<span><math><mi>⋅</mi></math></span>m<span><math><msup><mrow></mrow><mrow><mn>1</mn><mo>/</mo><mn>2</mn></mrow></msup></math></span> for the outer product, 0.64 ± 0.05 MPa<span><math><mi>⋅</mi></math></span>m<span><math><msup><mrow></mrow><mrow><mn>1</mn><mo>/</mo><mn>2</mn></mrow></msup></math></span> for the inner product, 0.66 ± 0.06 MPa<span><math><mi>⋅</mi></math></span>m<span><math><msup><mrow></mrow><mrow><mn>1</mn><mo>/</mo><mn>2</mn></mrow></msup></math></span> for Portlandite, and 1.24 ± 0.20 MPa<span><math><mi>⋅</mi></math></span>m<span><math><msup><mrow></mrow><mrow><mn>1</mn><mo>/</mo><mn>2</mn></mrow></msup></math></span> for clinker on well-hydrated sample. Two primary deformation mechanisms inherent in the micro-scratch process, material compaction and “ripping off”, were identified and their impact on fracture toughness and friction coefficient was quantified. Simulation of cracking and damage mechanisms, plus estimation of the otherwise unavailable tensile strength of compacted cement paste constituents, were successfully modeled using a Griffith-type fracture model.</p></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"185 ","pages":"Article 107623"},"PeriodicalIF":10.9,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141909498","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

The manufacture of natural hydraulic limes: Influence of raw materials' composition, calcination and slaking in the crystal-chemical properties of binders 天然液压石灰的制造：原料成分、煅烧和焙烧对粘结剂晶体化学性质的影响

IF 10.9 1区工程技术

Cement and Concrete Research Pub Date : 2024-08-06 DOI: 10.1016/j.cemconres.2024.107631

C. Parra-Fernández , A. Arizzi , M. Secco , G. Cultrone

{"title":"The manufacture of natural hydraulic limes: Influence of raw materials' composition, calcination and slaking in the crystal-chemical properties of binders","authors":"C. Parra-Fernández , A. Arizzi , M. Secco , G. Cultrone","doi":"10.1016/j.cemconres.2024.107631","DOIUrl":"10.1016/j.cemconres.2024.107631","url":null,"abstract":"<div><p>This study aims to achieve an in-depth understanding of the manufacturing process of natural hydraulic lime (NHL) by assessing the influence of raw materials' chemical- mineralogical composition and the effect of the slaking process. NHLs with variable hydraulicity were manufactured using 56 raw materials from carbonate outcrops in Andalusia (Spain). This study shows that siliceous limestones with microcrystalline quartz generate hydraulic phases after calcination. However, when the amount of this reactive silica exceeds 18% by weight, CaO is not formed, and only calcium silicates appear. It was also found that slaking of NHL leads to partial hydration of the most reactive calcium silicates, reducing the expected reactivity of the lime. Instead, exposure of NHL quicklimes to environmental relative humidity promotes the formation of disordered portlandite and reduces the partial hydration of hydraulic phases. Our findings demonstrate that standard slaking can be replaced by alternative methods for the studied binders.</p></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"185 ","pages":"Article 107631"},"PeriodicalIF":10.9,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0008884624002126/pdfft?md5=6138a387a9a85c9661236e8fcc34f3c7&pid=1-s2.0-S0008884624002126-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141909495","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

Investigation of self-desiccating cement-based materials for dihydrogen sequestration: Interactions between γ-MnO2/Ag2CO3 getter and the cement matrix 用于二氢封存的自干燥水泥基材料的研究：γ-MnO2/Ag2CO3吸附剂与水泥基质之间的相互作用

IF 10.9 1区工程技术

Cement and Concrete Research Pub Date : 2024-08-05 DOI: 10.1016/j.cemconres.2024.107628

Céline Cau Dit Coumes , Oriane Farcy , Hugo Danis , Jean-Baptiste Champenois , Pascal Antonucci , Adel Mesbah , David Lambertin

{"title":"Investigation of self-desiccating cement-based materials for dihydrogen sequestration: Interactions between γ-MnO2/Ag2CO3 getter and the cement matrix","authors":"Céline Cau Dit Coumes , Oriane Farcy , Hugo Danis , Jean-Baptiste Champenois , Pascal Antonucci , Adel Mesbah , David Lambertin","doi":"10.1016/j.cemconres.2024.107628","DOIUrl":"10.1016/j.cemconres.2024.107628","url":null,"abstract":"<div><p>Mitigating the release of dihydrogen resulting from metal corrosion or water radiolysis is an important issue for the disposal of certain types of cemented radwaste packages. The approach investigated in this work consists in adding an oxide getter (γ-MnO<sub>2</sub>/Ag<sub>2</sub>CO<sub>3</sub>) to the cement matrix. Since the efficiency of the getter decreases under wet environment, two self-desiccating binders (calcium sulfo-aluminate and magnesium potassium phosphate cements), are used to obtain significant desaturation of the pore network by the sole hydration reactions. The getter slightly influences the rate of cement hydration at early age, but has no effect afterwards. Sorption of ions released by dissolution of cement phases onto γ-MnO<sub>2</sub> is evidenced, as well as partial or total destabilization of silver carbonate. Nevertheless, the getter still enables to reduce strongly the outgassing of dihydrogen from mortars encapsulating Al-metal, which opens new perspectives to improve the conditioning of waste producing H<sub>2</sub> in a cement matrix.</p></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"185 ","pages":"Article 107628"},"PeriodicalIF":10.9,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141909506","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

Quantitative characterization of nano-scale pore structures in a consistent volume of cement paste subjected to heating via synchrotron X-ray nanoimaging 通过同步辐射 X 射线纳米成像定量表征受热水泥浆一致体积中的纳米级孔隙结构

IF 10.9 1区工程技术

Cement and Concrete Research Pub Date : 2024-08-03 DOI: 10.1016/j.cemconres.2024.107630

Heongwon Suh, Seongmin Cho, Gyeongryul Kim, Sungchul Bae

引用次数: 0