Tangwei Mi , Yongqiang Li , En-Hua Yang , Cise Unluer
{"title":"Use of sludge produced from reject brine as a supplementary cementitious material with enhanced carbonation capability","authors":"Tangwei Mi , Yongqiang Li , En-Hua Yang , Cise Unluer","doi":"10.1016/j.cemconcomp.2025.106051","DOIUrl":null,"url":null,"abstract":"<div><div>Sludge obtained from reject brine via a novel two-step approach involving precipitation and filtration was used as a supplementary material in reactive magnesia cement (RMC) and Portland cement (PC) mixes. Detailed evaluation of the performance and microstructure of the resultant cement pastes revealed the underlying mechanism. Incorporating 25 % (of the binder content) sludge in RMC mixes significantly increased the compressive strength under ambient and carbonation-based curing, which was more than doubled under the latter condition. While the strength of PC mixes decreased with the use of sludge, it still exceeded 30 MPa under carbonation. Increase in hydration heat observed in sludge-containing mixes was attributed to the presence of brucite acting as nucleation sites. ∼30 % reduction in CO<sub>2</sub> emissions and ∼25 % reduction in energy consumption was achieved by simply incorporating sludge in the designed mixes. Furthermore, sludge enhanced carbonation in RMC and PC mixes by increasing the amount of CO<sub>2</sub> sequestered at 28 days by 25.9 % and 41.1 %, respectively. Overall, the feasibility of re-purposing reject brine by directly using the produced sludge was demonstrated, offering a sustainable alternative for concrete production with a significantly reduced environmental impact.</div></div>","PeriodicalId":9865,"journal":{"name":"Cement & concrete composites","volume":"160 ","pages":"Article 106051"},"PeriodicalIF":10.8000,"publicationDate":"2025-03-20","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/S0958946525001337","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
Sludge obtained from reject brine via a novel two-step approach involving precipitation and filtration was used as a supplementary material in reactive magnesia cement (RMC) and Portland cement (PC) mixes. Detailed evaluation of the performance and microstructure of the resultant cement pastes revealed the underlying mechanism. Incorporating 25 % (of the binder content) sludge in RMC mixes significantly increased the compressive strength under ambient and carbonation-based curing, which was more than doubled under the latter condition. While the strength of PC mixes decreased with the use of sludge, it still exceeded 30 MPa under carbonation. Increase in hydration heat observed in sludge-containing mixes was attributed to the presence of brucite acting as nucleation sites. ∼30 % reduction in CO2 emissions and ∼25 % reduction in energy consumption was achieved by simply incorporating sludge in the designed mixes. Furthermore, sludge enhanced carbonation in RMC and PC mixes by increasing the amount of CO2 sequestered at 28 days by 25.9 % and 41.1 %, respectively. Overall, the feasibility of re-purposing reject brine by directly using the produced sludge was demonstrated, offering a sustainable alternative for concrete production with a significantly reduced environmental impact.
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.