Back to Search Start Over

Effect of Microwave Pretreatment on the Properties and Microstructure of Low-Concentration Carbon Dioxide Early Cured Cement-Based Materials

Authors :
Xiao Liang
Maosen Li
Lu Wang
Shuhua Liu
Source :
Buildings, Vol 14, Iss 4, p 1074 (2024)
Publication Year :
2024
Publisher :
MDPI AG, 2024.

Abstract

The utilization of microwave drying technology has expanded across various sectors due to its rapid processing speed, reduced operation time, lower sample temperatures, and consistent heating. In this research, microwave pretreatment was implemented prior to carbonation curing with low concentrations, and an array of tests including moisture content, compressive strength, carbonation depth, CO2 absorptivity, thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM), and mercury intrusion porosimetry (MIP) were utilized to investigate the effect of microwave pretreatment on the properties and microstructure of cementitious materials under early carbonation curing with low CO2 concentrations. The findings reveal that microwave pretreatment significantly decreases the moisture content within the test specimens, expediting the ingress of CO2 and improving the compressive strength of the specimens. At the same time, the effectiveness of microwave pretreatment in reducing moisture content diminishes as the pretreatment time increases. The absorption of CO2 is relatively rapid in the early stage of carbonation curing, with over 50% of the CO2 absorption occurring within the 0–6 h period of carbonation curing. The hydration products and microstructure of the uncarbonated part inside the specimens are generally consistent with the normal curing state. The formation of CaCO3 contributed to the densification of the specimen by infilling its internal voids, thereby enhancing its compressive strength. Although carbonation curing enlarges the average pore size of the samples, it also serves a filling function, making the samples more compact and reducing the porosity.

Details

Language :
English
ISSN :
20755309
Volume :
14
Issue :
4
Database :
Directory of Open Access Journals
Journal :
Buildings
Publication Type :
Academic Journal
Accession number :
edsdoj.426f5f3279554a22bf22d63d294c99ca
Document Type :
article
Full Text :
https://doi.org/10.3390/buildings14041074