Yaogang Tian, Jing Jiang, Kuo Ji, Jin Tian, Junpeng Yang, Kan Jia, Xin Lu
{"title":"条件对再生水泥浆粉中CO2活化质量的定量影响:目标产物的含量、形态和化学反应性以及CO2固存能力","authors":"Yaogang Tian, Jing Jiang, Kuo Ji, Jin Tian, Junpeng Yang, Kan Jia, Xin Lu","doi":"10.1016/j.cemconcomp.2025.106120","DOIUrl":null,"url":null,"abstract":"<div><div>Cement clinker production is a major contributor to CO<sub>2</sub>-intensive emissions and high energy consumption in the cement industry, necessitating urgent development of sustainable alternatives. In this study, thus, a CO<sub>2</sub>-activation recycled cement paste powder (ca-RCPP) with pozzolanic activity and aragonite whisker was synthesized by enhancing recycled cement paste powder (RCPP) through CO<sub>2</sub>. Meantime, the change rule of CO<sub>2</sub>-activation quality of ca-RCPP was quantitatively investigated and the related effect mechanism was elucidated under different CO<sub>2</sub>-activation conditions. The results showed that ca-RCPP was dominated by calcite under high CO<sub>2</sub> dissolution conditions. Increasing the concentration of crystal modifier (MgCl<sub>2</sub>·6H<sub>2</sub>O), CO<sub>2</sub>-activation temperature and rotation speed promoted a moderate reduction in CO<sub>3</sub><sup>2−</sup> saturation, which enhanced both the content and length-diameter ratio (L/D) of aragonite, thereby improving the chemical reactivity of ca-RCPP with 3CaO·Al<sub>2</sub>O<sub>3</sub>. However, excessively low CO<sub>3</sub><sup>2−</sup> saturation levels were proved counterproductive. Concurrently, silica gel content and CO<sub>2</sub> sequestration efficiency (<em>β</em>) always decreased under these conditions. Prolonged CO<sub>2</sub>-activation time increased aragonite content, <em>β</em>, silica gel content and pozzolanic activity of ca-RCPP, but shortened the L/D of aragonite. Elevated gas flux of CO<sub>2</sub> similarly enhanced <em>β</em> and silica gel content, but diminished both the content and L/D of aragonite. Correlation analysis demonstrated an overall synergistic relationship between these evaluation indexes of CO<sub>2</sub>-activation quality under the influence of most CO<sub>2</sub>-activation conditions. Additionally, the concentration of crystal modifier, CO<sub>2</sub>-activation time and CO<sub>2</sub>-activation temperature exerted greater influence on the CO<sub>2</sub>-activation quality of ca-RCPP than gas flux of CO<sub>2</sub> or rotation speed.</div></div>","PeriodicalId":9865,"journal":{"name":"Cement & concrete composites","volume":"162 ","pages":"Article 106120"},"PeriodicalIF":10.8000,"publicationDate":"2025-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Quantitative influence of conditions on CO2-activation quality in recycled cement paste powder: content, morphology and chemical reactivity of target product and CO2 sequestration capacity\",\"authors\":\"Yaogang Tian, Jing Jiang, Kuo Ji, Jin Tian, Junpeng Yang, Kan Jia, Xin Lu\",\"doi\":\"10.1016/j.cemconcomp.2025.106120\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>Cement clinker production is a major contributor to CO<sub>2</sub>-intensive emissions and high energy consumption in the cement industry, necessitating urgent development of sustainable alternatives. In this study, thus, a CO<sub>2</sub>-activation recycled cement paste powder (ca-RCPP) with pozzolanic activity and aragonite whisker was synthesized by enhancing recycled cement paste powder (RCPP) through CO<sub>2</sub>. Meantime, the change rule of CO<sub>2</sub>-activation quality of ca-RCPP was quantitatively investigated and the related effect mechanism was elucidated under different CO<sub>2</sub>-activation conditions. The results showed that ca-RCPP was dominated by calcite under high CO<sub>2</sub> dissolution conditions. Increasing the concentration of crystal modifier (MgCl<sub>2</sub>·6H<sub>2</sub>O), CO<sub>2</sub>-activation temperature and rotation speed promoted a moderate reduction in CO<sub>3</sub><sup>2−</sup> saturation, which enhanced both the content and length-diameter ratio (L/D) of aragonite, thereby improving the chemical reactivity of ca-RCPP with 3CaO·Al<sub>2</sub>O<sub>3</sub>. However, excessively low CO<sub>3</sub><sup>2−</sup> saturation levels were proved counterproductive. Concurrently, silica gel content and CO<sub>2</sub> sequestration efficiency (<em>β</em>) always decreased under these conditions. Prolonged CO<sub>2</sub>-activation time increased aragonite content, <em>β</em>, silica gel content and pozzolanic activity of ca-RCPP, but shortened the L/D of aragonite. Elevated gas flux of CO<sub>2</sub> similarly enhanced <em>β</em> and silica gel content, but diminished both the content and L/D of aragonite. Correlation analysis demonstrated an overall synergistic relationship between these evaluation indexes of CO<sub>2</sub>-activation quality under the influence of most CO<sub>2</sub>-activation conditions. Additionally, the concentration of crystal modifier, CO<sub>2</sub>-activation time and CO<sub>2</sub>-activation temperature exerted greater influence on the CO<sub>2</sub>-activation quality of ca-RCPP than gas flux of CO<sub>2</sub> or rotation speed.</div></div>\",\"PeriodicalId\":9865,\"journal\":{\"name\":\"Cement & concrete composites\",\"volume\":\"162 \",\"pages\":\"Article 106120\"},\"PeriodicalIF\":10.8000,\"publicationDate\":\"2025-05-12\",\"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/S0958946525002021\",\"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}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Cement & concrete composites","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0958946525002021","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}
Quantitative influence of conditions on CO2-activation quality in recycled cement paste powder: content, morphology and chemical reactivity of target product and CO2 sequestration capacity
Cement clinker production is a major contributor to CO2-intensive emissions and high energy consumption in the cement industry, necessitating urgent development of sustainable alternatives. In this study, thus, a CO2-activation recycled cement paste powder (ca-RCPP) with pozzolanic activity and aragonite whisker was synthesized by enhancing recycled cement paste powder (RCPP) through CO2. Meantime, the change rule of CO2-activation quality of ca-RCPP was quantitatively investigated and the related effect mechanism was elucidated under different CO2-activation conditions. The results showed that ca-RCPP was dominated by calcite under high CO2 dissolution conditions. Increasing the concentration of crystal modifier (MgCl2·6H2O), CO2-activation temperature and rotation speed promoted a moderate reduction in CO32− saturation, which enhanced both the content and length-diameter ratio (L/D) of aragonite, thereby improving the chemical reactivity of ca-RCPP with 3CaO·Al2O3. However, excessively low CO32− saturation levels were proved counterproductive. Concurrently, silica gel content and CO2 sequestration efficiency (β) always decreased under these conditions. Prolonged CO2-activation time increased aragonite content, β, silica gel content and pozzolanic activity of ca-RCPP, but shortened the L/D of aragonite. Elevated gas flux of CO2 similarly enhanced β and silica gel content, but diminished both the content and L/D of aragonite. Correlation analysis demonstrated an overall synergistic relationship between these evaluation indexes of CO2-activation quality under the influence of most CO2-activation conditions. Additionally, the concentration of crystal modifier, CO2-activation time and CO2-activation temperature exerted greater influence on the CO2-activation quality of ca-RCPP than gas flux of CO2 or rotation speed.
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.