{"title":"Regulating hydration and microstructure development of reactive MgO cement by citric acids","authors":"Huanhuan Wang , Shuang Liang , Xiangming Zhou , Pengkun Hou , Xin Cheng","doi":"10.1016/j.cemconcomp.2024.105832","DOIUrl":null,"url":null,"abstract":"<div><div>Reactive MgO cement (RMC) is a novel binder formed through the hydration and carbonation of MgO, but its low reactivity hinders its wider application. Preliminary research has suggested that citric acids can form compounds with Mg<sup>2+</sup> that regulate these processes, but the mechanism is yet to be understood well. This study investigated the effects of citric acids on the fresh and hardened properties of RMC. Results showed that the shear yield stress and plastic viscosity of the RMC pastes decreased with the addition of citric acids. Under standard curing, 4 <em>wt</em>% and 8 <em>wt</em>% citric acids increased the compressive strength of RMC by ∼100 % at 14 days. The adsorption of citrate on MgO inhibited the formation of brucite, forming an amorphous network-like microstructure crystallised after 14 days. Under CO<sub>2</sub> curing, the compressive strength of RMC with 8 <em>wt</em>% citric acids increased by 12 % at 14 days, which could be ascribed to the porous microstructure formed that promotes the uptake of CO<sub>2</sub> and the densification of the microstructure.</div></div>","PeriodicalId":9865,"journal":{"name":"Cement & concrete composites","volume":"155 ","pages":"Article 105832"},"PeriodicalIF":10.8000,"publicationDate":"2024-11-01","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/S0958946524004050","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
Reactive MgO cement (RMC) is a novel binder formed through the hydration and carbonation of MgO, but its low reactivity hinders its wider application. Preliminary research has suggested that citric acids can form compounds with Mg2+ that regulate these processes, but the mechanism is yet to be understood well. This study investigated the effects of citric acids on the fresh and hardened properties of RMC. Results showed that the shear yield stress and plastic viscosity of the RMC pastes decreased with the addition of citric acids. Under standard curing, 4 wt% and 8 wt% citric acids increased the compressive strength of RMC by ∼100 % at 14 days. The adsorption of citrate on MgO inhibited the formation of brucite, forming an amorphous network-like microstructure crystallised after 14 days. Under CO2 curing, the compressive strength of RMC with 8 wt% citric acids increased by 12 % at 14 days, which could be ascribed to the porous microstructure formed that promotes the uptake of CO2 and the densification of the microstructure.
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.