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

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

Nedeljković, Marija (TU Delft Materials and Environment)
Ghiassi, B. (University of Nottingham)
van der Laan, Sieger (Tata Steel)
Li, Z. (TU Delft Materials and Environment)
Ye, G. (TU Delft Materials and Environment)

2019

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.

Alkali-activated fly ash/slag
Carbonation
Curing condition
Pore solution

http://resolver.tudelft.nl/uuid:46100020-efdc-4cae-ae4b-26a64d2c8230

https://doi.org/10.1016/j.cemconres.2018.11.011

2019-11-27

0008-8846

Cement and Concrete Research, 116, 146-158

Institutional Repository

journal article

© 2019 Marija Nedeljković, B. Ghiassi, Sieger van der Laan, Z. Li, G. Ye