Kaiyin Zhao , Hengrui Liu , Lucen Hao , Shuangshuang Liu , Shipeng Zhang , Chi Sun Poon
{"title":"二氧化碳搅拌对新拌砂浆早期流变学和电化学性能的影响","authors":"Kaiyin Zhao , Hengrui Liu , Lucen Hao , Shuangshuang Liu , Shipeng Zhang , Chi Sun Poon","doi":"10.1016/j.cemconcomp.2024.105817","DOIUrl":null,"url":null,"abstract":"<div><div>The study aimed to elucidate the mechanism behind rheological modification due to CO<sub>2</sub> mixing at the mixing and post-mixing stages from an electrochemical perspective. The results indicated that CO<sub>2</sub> mixing reduced the flowability while increasing penetration resistance and static yield stress. The electrostatic attraction between particles with opposite surface charges and the bridging effect of calcium carbonate constitute the primary factors for influencing the rheological properties of mortar at an early age. The altered surface charge of carbonized cement particles, primarily resulting from CO<sub>2</sub> injection lowering the pH and ion concentration, reversed the zeta potential of particles from the traditionally negative charge (−3.59 mV) to a positive value (+13.3 mV). Furthermore, CO<sub>2</sub> mixing further enhanced the dissolution of cement particles and accelerated the hydration process, thereby increasing the rate of structural build-up. CO<sub>2</sub> mixing was demonstrated to be a potential rheological modifier for 3D-printed concrete applications.</div></div>","PeriodicalId":9865,"journal":{"name":"Cement & concrete composites","volume":"155 ","pages":"Article 105817"},"PeriodicalIF":10.8000,"publicationDate":"2024-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Effect of CO2 mixing on the rheological and electrochemical properties of fresh mortar at the early age\",\"authors\":\"Kaiyin Zhao , Hengrui Liu , Lucen Hao , Shuangshuang Liu , Shipeng Zhang , Chi Sun Poon\",\"doi\":\"10.1016/j.cemconcomp.2024.105817\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>The study aimed to elucidate the mechanism behind rheological modification due to CO<sub>2</sub> mixing at the mixing and post-mixing stages from an electrochemical perspective. The results indicated that CO<sub>2</sub> mixing reduced the flowability while increasing penetration resistance and static yield stress. The electrostatic attraction between particles with opposite surface charges and the bridging effect of calcium carbonate constitute the primary factors for influencing the rheological properties of mortar at an early age. The altered surface charge of carbonized cement particles, primarily resulting from CO<sub>2</sub> injection lowering the pH and ion concentration, reversed the zeta potential of particles from the traditionally negative charge (−3.59 mV) to a positive value (+13.3 mV). Furthermore, CO<sub>2</sub> mixing further enhanced the dissolution of cement particles and accelerated the hydration process, thereby increasing the rate of structural build-up. CO<sub>2</sub> mixing was demonstrated to be a potential rheological modifier for 3D-printed concrete applications.</div></div>\",\"PeriodicalId\":9865,\"journal\":{\"name\":\"Cement & concrete composites\",\"volume\":\"155 \",\"pages\":\"Article 105817\"},\"PeriodicalIF\":10.8000,\"publicationDate\":\"2024-10-26\",\"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/S0958946524003901\",\"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/S0958946524003901","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
摘要
该研究旨在从电化学角度阐明二氧化碳在混合和混合后阶段造成流变性改变的机理。结果表明,二氧化碳混合降低了流动性,同时增加了渗透阻力和静屈服应力。表面电荷相反的颗粒之间的静电吸引和碳酸钙的架桥效应是影响早期砂浆流变性能的主要因素。碳化水泥颗粒表面电荷的改变主要是由于二氧化碳的注入降低了 pH 值和离子浓度,使颗粒的 zeta 电位从传统的负电荷(-3.59 mV)逆转为正值(+13.3 mV)。此外,二氧化碳混合进一步促进了水泥颗粒的溶解,加速了水化过程,从而提高了结构形成的速度。二氧化碳混合被证明是 3D 打印混凝土应用中一种潜在的流变改性剂。
Effect of CO2 mixing on the rheological and electrochemical properties of fresh mortar at the early age
The study aimed to elucidate the mechanism behind rheological modification due to CO2 mixing at the mixing and post-mixing stages from an electrochemical perspective. The results indicated that CO2 mixing reduced the flowability while increasing penetration resistance and static yield stress. The electrostatic attraction between particles with opposite surface charges and the bridging effect of calcium carbonate constitute the primary factors for influencing the rheological properties of mortar at an early age. The altered surface charge of carbonized cement particles, primarily resulting from CO2 injection lowering the pH and ion concentration, reversed the zeta potential of particles from the traditionally negative charge (−3.59 mV) to a positive value (+13.3 mV). Furthermore, CO2 mixing further enhanced the dissolution of cement particles and accelerated the hydration process, thereby increasing the rate of structural build-up. CO2 mixing was demonstrated to be a potential rheological modifier for 3D-printed concrete applications.
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.