Carbonation induced phase evolution in alkali-activated slag/fly ash cements: The effect of silicate modulus of activators

Zhang, Jian and Shi, Caijun and Zhang, Zuhua (2019) Carbonation induced phase evolution in alkali-activated slag/fly ash cements: The effect of silicate modulus of activators. Construction and Building Materials, 223. pp. 566-582. ISSN 0950-0618


Abstract

In this study, the effects of silicate modulus of activators (Ms) on carbonation of alkali-activated slag/fly ash cements are studied and compared between natural (0.03–0.04% CO2) and accelerated (1% CO2) carbonation conditions, via XRD, FTIR and TG/DTG techniques. Carbonation results in the decalcification of the C-A-S-H gels and the formation of calcium carbonates and silica gels, while the N-A-S-H gels are essentially constant after carbonation. The main calcium carbonate phase after carbonation is calcite, and the increase of Ms leads to the generation of vaterite and aragonite. The carbonation behaviors of low-calcium system (20% slag) are different from the high-Ca systems (100% and 60% slag), while the carbonation rate and the amount of calcium carbonates generally decrease with the increase of Ms in all of the studied systems. This investigation provides an in-depth understanding of carbonation mechanisms of alkali-activated cements, and is essential for the establishment of carbonation models and prediction of long-term performances.


Statistics for USQ ePrint 37686
Statistics for this ePrint Item
Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Files associated with this item cannot be displayed due to copyright restrictions.
Faculty/School / Institute/Centre: Current - Institute for Advanced Engineering and Space Sciences - Centre for Future Materials (1 Jan 2017 -)
Faculty/School / Institute/Centre: Current - Institute for Advanced Engineering and Space Sciences - Centre for Future Materials (1 Jan 2017 -)
Date Deposited: 28 Jan 2020 03:08
Last Modified: 30 Jan 2020 02:43
Uncontrolled Keywords: Alkali-activated cements, Carbonation, Slag, Fly ash, Activators, Silicate modulus
Fields of Research : 09 Engineering > 0905 Civil Engineering > 090503 Construction Materials
Socio-Economic Objective: B Economic Development > 87 Construction > 8703 Construction Materials Performance and Processes > 870301 Cement and Concrete Materials
Identification Number or DOI: doi:0.1016/j.conbuildmat.2019.07.024
URI: http://eprints.usq.edu.au/id/eprint/37686

Actions (login required)

View Item Archive Repository Staff Only