Cement and Concrete Research最新文献_第9页

Quantifying the immobilization mechanisms of heavy metals by Calcium Silicate Hydrate (C-S-H): The case of Cu2+ 量化硅酸钙水合物（C-S-H）固定重金属的机制：以 Cu2+ 为例

IF 10.9 1区工程技术

Cement and Concrete Research Pub Date : 2024-10-10 DOI: 10.1016/j.cemconres.2024.107695

Qi Liu , Pan Feng , Lijing Shao , Chen Chen , Xin Liu , Yuefeng Ma , Lizhi Zhang , Guoqing Geng

{"title":"Quantifying the immobilization mechanisms of heavy metals by Calcium Silicate Hydrate (C-S-H): The case of Cu2+","authors":"Qi Liu , Pan Feng , Lijing Shao , Chen Chen , Xin Liu , Yuefeng Ma , Lizhi Zhang , Guoqing Geng","doi":"10.1016/j.cemconres.2024.107695","DOIUrl":"10.1016/j.cemconres.2024.107695","url":null,"abstract":"<div><div>Understanding the interactions between calcium silicate hydrate (C-S-H) and heavy metals is vital for optimizing the use of solid waste in cementitious materials. This paper introduces an innovative approach to elucidate the immobilization mechanism of Cu<sup>2+</sup>, a representative heavy metal. The roles of Ca<sup>2+</sup> and OH<sup>−</sup> in Cu<sup>2+</sup> immobilization were comprehensively investigated through being treated by C-S-H samples with varying interlayer Ca<sup>2+</sup> contents via meticulous immersion in ammonium chloride (NH<sub>4</sub>Cl). Our results indicate that Cu<sup>2+</sup> immobilization primarily occurs via complete substitution of interlayer Ca<sup>2+</sup> and partial substitution of intralayer Ca<sup>2+</sup>, with contributions of 40 % and 59 %, respectively, for a Ca/Si ratio of 1.2. Minor mechanisms like OH<sup>−</sup> complexation and surface adsorption account for the remaining immobilization. The formation of Si-O-Cu complexes was confirmed by X-ray photoelectron (XPS) and Extended X-ray Absorption Fine Structure (EXAFS) analysis. This study provides a quantitative methodology that informs strategies for sustainable cementitious waste utilization.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"186 ","pages":"Article 107695"},"PeriodicalIF":10.9,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142397812","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

Setting reaction of a olivine-based Mg-phosphate cement 橄榄石基磷酸镁水泥的凝结反应

IF 10.9 1区工程技术

Cement and Concrete Research Pub Date : 2024-10-10 DOI: 10.1016/j.cemconres.2024.107694

Davide Bernasconi , Alberto Viani , Lucie Zárybnická , Simone Bordignon , Jose R.A. Godinho , Alexey Maximenko , Cem Celikutku , Sadaf Fatima Jafri , Elisa Borfecchia , Quentin Wehrung , Roberto Gobetto , Alessandro Pavese

{"title":"Setting reaction of a olivine-based Mg-phosphate cement","authors":"Davide Bernasconi , Alberto Viani , Lucie Zárybnická , Simone Bordignon , Jose R.A. Godinho , Alexey Maximenko , Cem Celikutku , Sadaf Fatima Jafri , Elisa Borfecchia , Quentin Wehrung , Roberto Gobetto , Alessandro Pavese","doi":"10.1016/j.cemconres.2024.107694","DOIUrl":"10.1016/j.cemconres.2024.107694","url":null,"abstract":"<div><div>The cementitious properties of natural Mg-rich olivine when reacted with a phosphoric acid solution are investigated, as a function of acid concentration and liquid/solid mass ratio. The obtained cements are composed of residual olivine crystals and amorphous silica nanoparticles dispersed in a dense and compact newberyite (MgHPO<sub>4</sub>∙3H<sub>2</sub>O) matrix. The latter was mostly formed by packed micrometric tabular crystals, although evidence of the presence of a fraction of amorphous MgHPO<sub>4</sub> was also found. Water content in the raw mix was observed to play a pivotal role on the reaction pathway, either promoting porosity or hindering the crystallization of the products. Up to 57 % of olivine reactivity, whose dissolution was promoted by the curing temperature (60 °C) and low pH, was achieved. All in all, these results indicate that the industrial mineral olivine may serve a viable source of Mg for the production of phosphate cements.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"186 ","pages":"Article 107694"},"PeriodicalIF":10.9,"publicationDate":"2024-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142398535","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

Phase, structure, and hygroscopic property evolutions of alkali-silica reaction gels under freeze drying 冷冻干燥条件下碱硅反应凝胶的物相、结构和吸湿性能演变

IF 10.9 1区工程技术

Cement and Concrete Research Pub Date : 2024-10-09 DOI: 10.1016/j.cemconres.2024.107692

Arkabrata Sinha, Jianqiang Wei

{"title":"Phase, structure, and hygroscopic property evolutions of alkali-silica reaction gels under freeze drying","authors":"Arkabrata Sinha, Jianqiang Wei","doi":"10.1016/j.cemconres.2024.107692","DOIUrl":"10.1016/j.cemconres.2024.107692","url":null,"abstract":"<div><div>Alkali-silica reaction (ASR), a detrimental process causing volume expansion and cracking in concrete by forming hygroscopic and swellable gel-like products, has been a long-standing challenge faced by concrete structures across the world. Understanding the underlying mechanisms of formation, moisture uptake and swelling of ASR gels requires thorough characterizations, where an appropriate drying method to remove free water and stop the reactions in the samples is essential. This study aims to elucidate the effect of freeze-drying, an emerging drying technique increasingly employed in sample preparations, on the phase, molecular structure, and moisture absorption behavior of ASR gels. Towards this end, six ASR gels with three calcium-to-silica (Ca/Si) ratios (0.1, 0.3, and 0.5) and two alkali-to-silica [(Na + K)/Si] ratios of 0.3 (low-alkali gels) and 1.0 (high-alkali gels) were studied. The results indicate that the chemical bonds and mineral components of ASR gels can be maintained during the removal of free and loosely bound water in freeze drying, while slight changes in crystallization and relative contents of alkali-silicate hydrate and calcium silicate hydrate phases were observed, in particular, for the high-alkali ASR gels. Although slight decreases in Q<sup>1</sup>, Q<sup>2,</sup> and Q<sup>3</sup> silica polymerization sites and increases in the mean chain length and degree of polymerization were observed from the nuclear magnetic resonance (NMR) spectroscopy, the intrinsic layered silicate structure of ASR gels remains. The moisture absorption of low-alkali and high-alkali ASR gels was found to be governed by gel pores and mesopores, respectively. After freeze-drying, slight increases in moisture sorption (a 6.8 % increase in absorption and a 2.2 % decrease in desorption) and enhanced hysteresis were observed from the low-alkali gels. The high-alkali gels, however, showed a slight decrease in hygroscopicity along with a 16.6 % reduction of mesopores.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"186 ","pages":"Article 107692"},"PeriodicalIF":10.9,"publicationDate":"2024-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142385993","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

Plugging effect of fine pore water in OPC and LC3 paste during accelerated carbonation monitored via single-sided nuclear magnetic resonance spectroscopy 通过单面核磁共振波谱监测加速碳化过程中 OPC 和 LC3 浆料中细小孔隙水的堵塞效应

IF 10.9 1区工程技术

Cement and Concrete Research Pub Date : 2024-10-08 DOI: 10.1016/j.cemconres.2024.107688

Luge Cheng , Ryo Kurihara , Takahiro Ohkubo , Ryoma Kitagaki , Atsushi Teramoto , Yuya Suda , Ippei Maruyama

引用次数: 0

New insights on the basic creep mechanism of one-part alkali activated slag and fly ash paste 关于单组分碱激活炉渣和粉煤灰浆基本蠕变机理的新见解

IF 10.9 1区工程技术

Cement and Concrete Research Pub Date : 2024-10-08 DOI: 10.1016/j.cemconres.2024.107691

Han Gao , Igor Shikhov , Ehab Hamed , Ailar Hajimohammadi , Iman Al-Damad , Christoph Arns , Stephen J. Foster

引用次数: 0

Insights on the mechanical properties and failure mechanisms of calcium silicate hydrates based on deep-learning potential molecular dynamics 基于深度学习潜在分子动力学的硅酸钙水合物力学性能和失效机理透视

IF 10.9 1区工程技术

Cement and Concrete Research Pub Date : 2024-10-02 DOI: 10.1016/j.cemconres.2024.107690

Weihuan Li , Chenchen Xiong , Yang Zhou , Wentao Chen , Yangzezhi Zheng , Wei Lin , Jiarui Xing

{"title":"Insights on the mechanical properties and failure mechanisms of calcium silicate hydrates based on deep-learning potential molecular dynamics","authors":"Weihuan Li , Chenchen Xiong , Yang Zhou , Wentao Chen , Yangzezhi Zheng , Wei Lin , Jiarui Xing","doi":"10.1016/j.cemconres.2024.107690","DOIUrl":"10.1016/j.cemconres.2024.107690","url":null,"abstract":"<div><div>The molecular-scale mechanical properties of calcium silicate hydrates are crucial to the macro performance of cementitious materials, while achieving coincidence between accuracy and efficiency in computational simulations still remains a challenge. This study utilizes a deep-learning potential, specifically developed for calcium silicate hydrates based on artificial neural network, to achieve molecular dynamics simulations with accuracy comparable to first-principle methods. With this potential, the elastic properties and uniaxial mechanical behaviors are explored, wherein the anisotropy and impact mechanism of calcium ratios are analyzed. The results add to evidence that the deep-learning potential possess a higher accuracy than common force fields. The anisotropy of elastic modulus is mainly attributed to different atomic interactions in various directions, while the anisotropy of strength is additionally affected by the form of failure. This study may advance the accurate molecular-scale simulation and deepen the understanding of the strength source and cohesion mechanism of cement-based materials.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"186 ","pages":"Article 107690"},"PeriodicalIF":10.9,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142369632","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

Importance of adsorption compared with complexation for retarding C3S hydration via adding sodium gluconate 在通过添加葡萄糖酸钠延缓 C3S 水化方面，吸附作用与络合作用相比具有重要意义

IF 10.9 1区工程技术

Cement and Concrete Research Pub Date : 2024-10-02 DOI: 10.1016/j.cemconres.2024.107686

Guitao Luo , Muyu Liu , Hua Li , Yang Liu , Hongbo Tan , Qimin Liu

{"title":"Importance of adsorption compared with complexation for retarding C3S hydration via adding sodium gluconate","authors":"Guitao Luo , Muyu Liu , Hua Li , Yang Liu , Hongbo Tan , Qimin Liu","doi":"10.1016/j.cemconres.2024.107686","DOIUrl":"10.1016/j.cemconres.2024.107686","url":null,"abstract":"<div><div>Adsorption effect on particle surfaces and complexation effect with free Ca<sup>2+</sup> mostly determine the retarding performance of organic admixtures on cement hydration. However, it is difficult to identify which effect plays a more important role in retarding hydration by experimental methods. Here, a theoretical model was developed to investigate the retarding mechanisms of sodium gluconate (SG) on hydration of tricalcium silicate (C<sub>3</sub>S). Based on obstruction theory and complexation reaction kinetics, effects of adsorption and complexation were simulated to examine the retarding performance of C<sub>3</sub>S hydration with addition of SG. The proposed model well predicted the effect of additional dosing of SG on the retarding performance of C<sub>3</sub>S hydration. Theoretical parameter studies demonstrated that adsorption ratio contributed much largely to the delays in C<sub>3</sub>S hydration, compared with rate constant of complex generation. Therefore, it is confirmed that adsorption plays a more important role in regulating the retarding mechanism of C<sub>3</sub>S hydration.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"186 ","pages":"Article 107686"},"PeriodicalIF":10.9,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142369637","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

Packing properties assessment of cement and alternative powders: Artefacts and protocols 水泥和替代粉料的填料特性评估：工件和规程

IF 10.9 1区工程技术

Cement and Concrete Research Pub Date : 2024-09-28 DOI: 10.1016/j.cemconres.2024.107685

Hela Bessaies-Bey , Xiaohan Yu , Wenqiang Zuo , Oumayma Ahmadah , Janine Deou , Laura Caneda-Martínez , Nicolas Roussel

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Experimental investigation of the impact of additives in low clinker cementitious materials on multi-ion transference numbers and diffusion coefficients 低熟料胶凝材料中添加剂对多离子转移数和扩散系数影响的实验研究

IF 10.9 1区工程技术

Cement and Concrete Research Pub Date : 2024-09-26 DOI: 10.1016/j.cemconres.2024.107687

Rachid Cherif , Carmen Andrade , Abdelkarim Aït-Mokhtar

{"title":"Experimental investigation of the impact of additives in low clinker cementitious materials on multi-ion transference numbers and diffusion coefficients","authors":"Rachid Cherif , Carmen Andrade , Abdelkarim Aït-Mokhtar","doi":"10.1016/j.cemconres.2024.107687","DOIUrl":"10.1016/j.cemconres.2024.107687","url":null,"abstract":"<div><div>In this paper, multi-ion transference numbers were determined throughout the chloride migration testing of low clinker cement-based materials. For this purpose, five cement pastes were studied: pure Portland paste (as a reference) and four other pastes, based on limestone filler, fly ash, slag or silica fume. The transference numbers were calculated from the concentration evolution in the three zones of the migration cell (catholyte, anolyte and sample), considering that: (i) ions moved in the catholyte and anolyte; (ii) ions leached from the sample; (iii) ions were generated from the electrode processes, and (iv) the pore solution of the sample evolved during the test. The chloride transference numbers of pastes with pure Portland cement, limestone filler, fly ash, slag or silica fume are almost zero at the beginning of the migration test but 0.23; 0.18; 0.06; 0.05 and 0.20 at the end of the test, respectively. The ion transference numbers obtained were used for the calculation of diffusion coefficients of chlorides, sodium and potassium using the Nernst-Einstein equation.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"186 ","pages":"Article 107687"},"PeriodicalIF":10.9,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142322770","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

Tensile strength and failure mechanism of rock–cement sample: Roles of curing temperature, nano-silica and rock type 岩石-水泥样品的拉伸强度和破坏机理：固化温度、纳米二氧化硅和岩石类型的作用

IF 10.9 1区工程技术

Cement and Concrete Research Pub Date : 2024-09-25 DOI: 10.1016/j.cemconres.2024.107673

Rongwei Yang , Shan He , Junyao Liu , Jiyun Shen , Linlin Wang , Yongjin Yu , Dongwei Hou

{"title":"Tensile strength and failure mechanism of rock–cement sample: Roles of curing temperature, nano-silica and rock type","authors":"Rongwei Yang , Shan He , Junyao Liu , Jiyun Shen , Linlin Wang , Yongjin Yu , Dongwei Hou","doi":"10.1016/j.cemconres.2024.107673","DOIUrl":"10.1016/j.cemconres.2024.107673","url":null,"abstract":"<div><div>Understanding the tensile strength and failure mechanism of rock–cement interfacial transition zone (ITZ) is of vital significance to the sealing integrity of cement sheath under downhole condition. Taking advantage of multiple techniques, i.e., digital image correlation (DIC), nano-indentation, XRD-Rietveld analysis, <span><math><mrow><msup><mrow></mrow><mrow><mn>29</mn></mrow></msup><mtext>Si</mtext></mrow></math></span> MAS solid NMR, and SEM-EDX, this study is devoted to investigating the impacts of curing temperature, rock type, and the addition of nano-silica (NS), on the tensile strength and failure mechanism of rock–cement sample. The experimental results show that both the curing temperature and the addition of NS leads to the formation of more C-S-H, which densifies the ITZ microstructure and responsible for high tensile strength of rock–cement samples; the tensile strengths of shale-cement samples are consistently higher than those of sandstone-cement sample; the crack velocities for rock–cement samples under three-point bending tests are approximately 1 mm/s, the crack velocities for rock–cement samples are slowed down when the NS is incorporated in cement paste, but they are independent on the rock type and curing temperature.</div></div>","PeriodicalId":266,"journal":{"name":"Cement and Concrete Research","volume":"186 ","pages":"Article 107673"},"PeriodicalIF":10.9,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142319669","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