Performance of CO2-Cured Alkali-Activated Slag Pastes During Curing and Exposure

International Journal of Concrete Structures and Materials

Research

Jae Hong Kim¹  Yubin Jun¹  Seong Ho Han¹ 

[1] Department of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology, 34141, Daejeon, Korea;

关键词: CO curing;    Amorphous CaCO;    Calcite;    CCUS;    Alkali-activated slag;   

DOI  :  10.1186/s40069-022-00563-3

 received in 2022-07-06, accepted in 2022-09-24,  发布年份 2022

来源: Springer

【 摘 要 】

This study investigated the efficiency of CO2 curing in blast-furnace slag pastes activated with three concentrations of KOH solution (3, 4, and 5 M). The CO2 curing was applied into the alkali-activated slag paste for 3 days. The CO2-cured pastes were subjected to subsequent curing in a water bath or exposed to seawater. The mechanical properties and characteristics of the reaction products were compared. Full strength can be obtained within 3 days of the early CO2 curing. The strength remained almost constant regardless of the activator concentration. The CO2-cured samples produced more CaCO3 after exposure to the seawater. The carbonates filled the micropores of the samples, and no strength reduction was observed. The hydrates Ca(OH)2 and C–S–H(I) are carbonated, forming calcite and amorphous CaCO3 during the subsequent curing and exposure to seawater as well as the CO2 curing. A less dense matrix with a lower activator concentration facilitated the diffusion of CO2 and promoted early carbonation in the paste. The polymerization of C–S–H(I) was relatively slow with low activity, and within the period of CO2 curing, more carbonates were produced in the sample prepared at a low activator concentration.

【 授权许可】

CC BY   
© The Author(s) 2022

【 图 表 】

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