{"title":"The impact of forced early-age carbonation on the hydration of cementitious materials","authors":"","doi":"10.1016/j.conbuildmat.2024.138781","DOIUrl":null,"url":null,"abstract":"<div><div>CO<sub>2</sub> curing has emerged as a promising method for carbon sequestration in cementitious materials. However, the complex interactions during CO<sub>2</sub> curing and the impact on the maturation pathways of cement during hydration remain a significant research gap. This paper introduces significant innovations in the study of CO<sub>2</sub> curing cement using (bi)-carbonate additives in both OPC and C<sub>3</sub>S systems to address a critical challenge in measuring the heat release during CO<sub>2</sub> curing due to instrumental limitations—specifically, the difficulty of simultaneously introducing CO<sub>2</sub> gas into the system and measuring the reaction heat in real-time. The findings reveal that early-stage addition of HCO<sub>3</sub><sup>-</sup>/CO<sub>3</sub><sup>2-</sup> leads to varied calcium carbonate polymorphs and a distinctive C-S-H/CaCO<sub>3</sub> composite with a clustered morphology. This configuration offers additional sites for further hydration/carbonation, leading to a more complete and rapid development of the products. Moreover, the research utilizes in-situ TGA to uncover a novel three-phase competitive reaction process—comprising induction, acceleration, and deceleration phases—between hydration and carbonation, with the availability of Ca<sup>2+</sup> ions being a critical factor. Finally, the study also reveals a preferential formation of Type II and III carbonates, offering insights into optimizing CO<sub>2</sub> curing for improved cementitious material performance. This dynamic perspective provides new insights into the interplay between these two processes, offering a more comprehensive understanding of the effects of forced early-age carbonation on cement hydration.</div></div>","PeriodicalId":288,"journal":{"name":"Construction and Building Materials","volume":null,"pages":null},"PeriodicalIF":7.4000,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Construction and Building Materials","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0950061824039230","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
CO2 curing has emerged as a promising method for carbon sequestration in cementitious materials. However, the complex interactions during CO2 curing and the impact on the maturation pathways of cement during hydration remain a significant research gap. This paper introduces significant innovations in the study of CO2 curing cement using (bi)-carbonate additives in both OPC and C3S systems to address a critical challenge in measuring the heat release during CO2 curing due to instrumental limitations—specifically, the difficulty of simultaneously introducing CO2 gas into the system and measuring the reaction heat in real-time. The findings reveal that early-stage addition of HCO3-/CO32- leads to varied calcium carbonate polymorphs and a distinctive C-S-H/CaCO3 composite with a clustered morphology. This configuration offers additional sites for further hydration/carbonation, leading to a more complete and rapid development of the products. Moreover, the research utilizes in-situ TGA to uncover a novel three-phase competitive reaction process—comprising induction, acceleration, and deceleration phases—between hydration and carbonation, with the availability of Ca2+ ions being a critical factor. Finally, the study also reveals a preferential formation of Type II and III carbonates, offering insights into optimizing CO2 curing for improved cementitious material performance. This dynamic perspective provides new insights into the interplay between these two processes, offering a more comprehensive understanding of the effects of forced early-age carbonation on cement hydration.
期刊介绍:
Construction and Building Materials offers an international platform for sharing innovative and original research and development in the realm of construction and building materials, along with their practical applications in new projects and repair practices. The journal publishes a diverse array of pioneering research and application papers, detailing laboratory investigations and, to a limited extent, numerical analyses or reports on full-scale projects. Multi-part papers are discouraged.
Additionally, Construction and Building Materials features comprehensive case studies and insightful review articles that contribute to new insights in the field. Our focus is on papers related to construction materials, excluding those on structural engineering, geotechnics, and unbound highway layers. Covered materials and technologies encompass cement, concrete reinforcement, bricks and mortars, additives, corrosion technology, ceramics, timber, steel, polymers, glass fibers, recycled materials, bamboo, rammed earth, non-conventional building materials, bituminous materials, and applications in railway materials.