Renjie Zhou , Yunjie Luo , Mingfang Ba , Zihua Zhang , Jianghua Fang , Chi Sun Poon , Xiaoliang Fang
{"title":"Value-added recycling of waste concrete fines into alternative aggregates for river sand conservation","authors":"Renjie Zhou , Yunjie Luo , Mingfang Ba , Zihua Zhang , Jianghua Fang , Chi Sun Poon , Xiaoliang Fang","doi":"10.1016/j.jcou.2024.102802","DOIUrl":null,"url":null,"abstract":"<div><p>Due to the depletion of river sand, the construction industry is eager to develop upcycling techniques for transforming secondary by-products derived from construction and demolition (C&D) waste into quality fine aggregates. This paper presents a study of replacing river sand with enhanced recycled fine aggregate through a wet carbonation process developed by the authors previously. The fine recycled concrete aggregate (FRCA) ranging from 0.15 to 5 mm was prepared by demolishing a concrete with a known mixture design. After wet carbonation, the particle size, water absorption, and density of the FRCA were tested and compared with the original samples. The chemical characteristics of the original and carbonated FRCA (C-FRCA) were analyzed by a series of experiments. The results showed that (1) an increase of carbonation products and a significant reduction of hydration products; (2) microscopic observation of the C-FRCA showed a surface layer densified by calcite after wet carbonation; and (3) no significant strength loss were observed when replacing up to 50% river sand by C-FRCA in mortar specimens. The potential environmental and economic impacts were also analyzed.</p></div>","PeriodicalId":350,"journal":{"name":"Journal of CO2 Utilization","volume":null,"pages":null},"PeriodicalIF":7.2000,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2212982024001379/pdfft?md5=c7dc23d804e7f62397bf958fc183021f&pid=1-s2.0-S2212982024001379-main.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of CO2 Utilization","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S2212982024001379","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
Due to the depletion of river sand, the construction industry is eager to develop upcycling techniques for transforming secondary by-products derived from construction and demolition (C&D) waste into quality fine aggregates. This paper presents a study of replacing river sand with enhanced recycled fine aggregate through a wet carbonation process developed by the authors previously. The fine recycled concrete aggregate (FRCA) ranging from 0.15 to 5 mm was prepared by demolishing a concrete with a known mixture design. After wet carbonation, the particle size, water absorption, and density of the FRCA were tested and compared with the original samples. The chemical characteristics of the original and carbonated FRCA (C-FRCA) were analyzed by a series of experiments. The results showed that (1) an increase of carbonation products and a significant reduction of hydration products; (2) microscopic observation of the C-FRCA showed a surface layer densified by calcite after wet carbonation; and (3) no significant strength loss were observed when replacing up to 50% river sand by C-FRCA in mortar specimens. The potential environmental and economic impacts were also analyzed.
期刊介绍:
The Journal of CO2 Utilization offers a single, multi-disciplinary, scholarly platform for the exchange of novel research in the field of CO2 re-use for scientists and engineers in chemicals, fuels and materials.
The emphasis is on the dissemination of leading-edge research from basic science to the development of new processes, technologies and applications.
The Journal of CO2 Utilization publishes original peer-reviewed research papers, reviews, and short communications, including experimental and theoretical work, and analytical models and simulations.