Jing Xie , Zemei Wu , Xuanhan Zhang , Xiang Hu , Caijun Shi
{"title":"揭示不同温度下控制富菱镁矿水泥基材料强度和微结构演变的机制","authors":"Jing Xie , Zemei Wu , Xuanhan Zhang , Xiang Hu , Caijun Shi","doi":"10.1016/j.cemconcomp.2024.105765","DOIUrl":null,"url":null,"abstract":"<div><div>The effect of temperature on the properties of belite-rich cement-based (BRC) materials is different from that on Portland cement (PC). This study provides a comprehensive understanding of the mechanisms controlling strength and microstructural evolution at different temperatures, especially C-S-H characteristics, of BRC materials. Phase assemblage, pore structure, and microscopic morphology of BRC paste, as well as phase composition and structure, chemically bound water, and bulk density of C-S-H were investigated using X-ray diffraction (XRD), thermogravimetric analysis (TGA), <sup>1</sup>H and <sup>29</sup>Si nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), and energy dispersive spectrometer (EDS). The strength of BRC mortar increased with temperature is because of the higher hydration degree of β-C<sub>2</sub>S, lower porosity (except for 60 °C), and increased main chain length (MCL) of C-S-H. Hydration degrees of 28-d β-C<sub>2</sub>S and C<sub>3</sub>S increased by 202.5 % and 16.3 %, respectively, while MCL increased by 39.4 % from 5 to 60 °C. The higher temperature sensitivity of β-C<sub>2</sub>S is due to its activation energy being 12.4 % greater than that of C<sub>3</sub>S in BRC paste. Additionally, gel porosity decreased with temperature due to decreased bound water content and increased 16.7 % bulk density of C-S-H from 5 to 60 °C. Finally, the CaO/SiO<sub>2</sub> was inversely proportional to MCL and bulk density, but positively to H<sub>2</sub>O/SiO<sub>2</sub>. The findings deepen the mechanistic understandings of the hydration kinetics and microstructural evolution for temperature-affected BRC material.</div></div>","PeriodicalId":9865,"journal":{"name":"Cement & concrete composites","volume":"154 ","pages":"Article 105765"},"PeriodicalIF":10.8000,"publicationDate":"2024-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Uncovering the mechanism controlling strength and microstructural evolution of belite-rich cement-based materials at different temperatures\",\"authors\":\"Jing Xie , Zemei Wu , Xuanhan Zhang , Xiang Hu , Caijun Shi\",\"doi\":\"10.1016/j.cemconcomp.2024.105765\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>The effect of temperature on the properties of belite-rich cement-based (BRC) materials is different from that on Portland cement (PC). This study provides a comprehensive understanding of the mechanisms controlling strength and microstructural evolution at different temperatures, especially C-S-H characteristics, of BRC materials. Phase assemblage, pore structure, and microscopic morphology of BRC paste, as well as phase composition and structure, chemically bound water, and bulk density of C-S-H were investigated using X-ray diffraction (XRD), thermogravimetric analysis (TGA), <sup>1</sup>H and <sup>29</sup>Si nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), and energy dispersive spectrometer (EDS). The strength of BRC mortar increased with temperature is because of the higher hydration degree of β-C<sub>2</sub>S, lower porosity (except for 60 °C), and increased main chain length (MCL) of C-S-H. Hydration degrees of 28-d β-C<sub>2</sub>S and C<sub>3</sub>S increased by 202.5 % and 16.3 %, respectively, while MCL increased by 39.4 % from 5 to 60 °C. The higher temperature sensitivity of β-C<sub>2</sub>S is due to its activation energy being 12.4 % greater than that of C<sub>3</sub>S in BRC paste. Additionally, gel porosity decreased with temperature due to decreased bound water content and increased 16.7 % bulk density of C-S-H from 5 to 60 °C. Finally, the CaO/SiO<sub>2</sub> was inversely proportional to MCL and bulk density, but positively to H<sub>2</sub>O/SiO<sub>2</sub>. The findings deepen the mechanistic understandings of the hydration kinetics and microstructural evolution for temperature-affected BRC material.</div></div>\",\"PeriodicalId\":9865,\"journal\":{\"name\":\"Cement & concrete composites\",\"volume\":\"154 \",\"pages\":\"Article 105765\"},\"PeriodicalIF\":10.8000,\"publicationDate\":\"2024-09-26\",\"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/S095894652400338X\",\"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/S095894652400338X","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}
Uncovering the mechanism controlling strength and microstructural evolution of belite-rich cement-based materials at different temperatures
The effect of temperature on the properties of belite-rich cement-based (BRC) materials is different from that on Portland cement (PC). This study provides a comprehensive understanding of the mechanisms controlling strength and microstructural evolution at different temperatures, especially C-S-H characteristics, of BRC materials. Phase assemblage, pore structure, and microscopic morphology of BRC paste, as well as phase composition and structure, chemically bound water, and bulk density of C-S-H were investigated using X-ray diffraction (XRD), thermogravimetric analysis (TGA), 1H and 29Si nuclear magnetic resonance (NMR), scanning electron microscopy (SEM), and energy dispersive spectrometer (EDS). The strength of BRC mortar increased with temperature is because of the higher hydration degree of β-C2S, lower porosity (except for 60 °C), and increased main chain length (MCL) of C-S-H. Hydration degrees of 28-d β-C2S and C3S increased by 202.5 % and 16.3 %, respectively, while MCL increased by 39.4 % from 5 to 60 °C. The higher temperature sensitivity of β-C2S is due to its activation energy being 12.4 % greater than that of C3S in BRC paste. Additionally, gel porosity decreased with temperature due to decreased bound water content and increased 16.7 % bulk density of C-S-H from 5 to 60 °C. Finally, the CaO/SiO2 was inversely proportional to MCL and bulk density, but positively to H2O/SiO2. The findings deepen the mechanistic understandings of the hydration kinetics and microstructural evolution for temperature-affected BRC material.
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.