Effect of curing conditions on the pore solution and carbonation resistance of alkali-activated fly ash and slag pastes

Nedeljkovi?, Marija; Ghiassi, Bahman; van der Laan, Sieger; Li, Zhenming; Ye, Guang

Abstract

The effect of curing conditions (sealed and unsealed) on the pore solution composition and carbonation resistance of different binary alkali-activated fly ash (FA) and ground granulated blast furnace slag (GBFS) pastes is investigated in this study. The studied mixtures were with FA/GBFS ratios of 100:0, 70:30; 50:50, 30:70, 0:100. Ordinary Portland cement (OPC) and Cement III/B (70?wt% of GBFS and 30?wt% OPC) pastes with the same precursor content were also studied to provide a baseline for comparison. Accelerated carbonation conditions (1% (v/v) CO2, 60% RH for 500?days) were considered for evaluating the carbonation resistance of the pastes.

The results show a substantial lower [Na+] in the pore solution of the unsealed cured samples compared to the sealed cured samples. It is also found that unsealed curing of the samples leads to a faster carbonation rate. Additionally, it is observed that the carbonation rate decreases with increasing GBFS content independent of the curing conditions. The potential risks with respect to carbonation of the pore solution are also identified and discussed.

Citation

Nedeljkovi?, M., Ghiassi, B., van der Laan, S., Li, Z., & Ye, G. (2019). Effect of curing conditions on the pore solution and carbonation resistance of alkali-activated fly ash and slag pastes. Cement and Concrete Research, 116, 146-158. https://doi.org/10.1016/j.cemconres.2018.11.011

• Journal Article Type: Article
• Acceptance Date: Nov 14, 2018
• Online Publication Date: Nov 27, 2018
• Publication Date: 2019-02
• Deposit Date: Nov 29, 2018
• Publicly Available Date: Nov 28, 2019
• Journal: Cement and Concrete Research
• Print ISSN: 0008-8846
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 116
• Pages: 146-158
• DOI: https://doi.org/10.1016/j.cemconres.2018.11.011
• Keywords: Alkali-activated fly ash/slag; Curing condition; Pore solution; Carbonation
• Public URL: https://nottingham-repository.worktribe.com/output/1338136
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S0008884618303272?via%3Dihub