{"title":"Early hydration and microstructure formation of ultra-rapid hardening alkali-activated slag cement (URHA) at presence of MgO","authors":"Ziye Huang , Zuhua Zhang , Cheng Shi , Yingcan Zhu , Zhengning Zhou , Xiaolong Jia , Qiang Ren , Zhengwu Jiang","doi":"10.1016/j.cemconcomp.2025.106057","DOIUrl":null,"url":null,"abstract":"<div><div>The fundamentals of hydration process of an ultra-rapid hardening alkali-activated slag cement (URHA) was studied for understanding the link between mechanical properties and microstructure development. By employing combined application of Raman spectroscopy, thermogravimetry (TG), X-ray diffractometry (XRD) and hydrogen low field <sup>1</sup>H nuclear magnetic resonance (LF <sup>1</sup>H NMR), it revealed that the mixing MgO into the URHA led to the formation of magnesium silicate hydrates (M-S-H), followed by the rapid development of calcium-alumino-silicate hydrates (C-A-S-H) and hydrotalcite (Ht). This not only altered the composition of the hydration products but also increased the reaction extent of early slag reactions, resulting in the formation of a more compact microstructure. The presence of MgO was proven to reduce chemical shrinkage (by 57.6 % when 12 % MgO was used), and increased compressive strength at 1 h. The formation and spacial distribution of Mg-containing phases were found to have positive effect on sustaining strength development in the later stages of 1 day and 3 days. This study provides an insight of the hydration mechanism of MgO-modified URHA, which can help predict hydration kinetics and performance for real applications.</div></div>","PeriodicalId":9865,"journal":{"name":"Cement & concrete composites","volume":"160 ","pages":"Article 106057"},"PeriodicalIF":10.8000,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Cement & concrete composites","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0958946525001398","RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CONSTRUCTION & BUILDING TECHNOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
The fundamentals of hydration process of an ultra-rapid hardening alkali-activated slag cement (URHA) was studied for understanding the link between mechanical properties and microstructure development. By employing combined application of Raman spectroscopy, thermogravimetry (TG), X-ray diffractometry (XRD) and hydrogen low field 1H nuclear magnetic resonance (LF 1H NMR), it revealed that the mixing MgO into the URHA led to the formation of magnesium silicate hydrates (M-S-H), followed by the rapid development of calcium-alumino-silicate hydrates (C-A-S-H) and hydrotalcite (Ht). This not only altered the composition of the hydration products but also increased the reaction extent of early slag reactions, resulting in the formation of a more compact microstructure. The presence of MgO was proven to reduce chemical shrinkage (by 57.6 % when 12 % MgO was used), and increased compressive strength at 1 h. The formation and spacial distribution of Mg-containing phases were found to have positive effect on sustaining strength development in the later stages of 1 day and 3 days. This study provides an insight of the hydration mechanism of MgO-modified URHA, which can help predict hydration kinetics and performance for real applications.
期刊介绍:
Cement & concrete composites focuses on advancements in cement-concrete composite technology and the production, use, and performance of cement-based construction materials. It covers a wide range of materials, including fiber-reinforced composites, polymer composites, ferrocement, and those incorporating special aggregates or waste materials. Major themes include microstructure, material properties, testing, durability, mechanics, modeling, design, fabrication, and practical applications. The journal welcomes papers on structural behavior, field studies, repair and maintenance, serviceability, and sustainability. It aims to enhance understanding, provide a platform for unconventional materials, promote low-cost energy-saving materials, and bridge the gap between materials science, engineering, and construction. Special issues on emerging topics are also published to encourage collaboration between materials scientists, engineers, designers, and fabricators.