Effect of alkali dosage and silicate modulus on carbonation of alkali-activated slag mortars

Shi, Zhenguo and Shi, Caijun and Wan, Shu and Li, Ning and Zhang, Zuhua (2018) Effect of alkali dosage and silicate modulus on carbonation of alkali-activated slag mortars. Cement and Concrete Research, 113. pp. 55-64. ISSN 0008-8846

Abstract

The long-term durability and their mechanisms of alkali-activated cement based materials have remained largely elusive. In this paper, carbonation of alkali-activated slag (AAS) mortars activated by NaOH and waterglass with different alkali dosages and silicate moduli has been investigated after exposure to 3 ± 0.2% (v/v) CO2 at 20 ± 2 °C/65 ± 5% RH for 56 days. The results show that carbonation resistance of the AAS mortars increases with increase of not only alkali dosage but also silicate modulus. In addition to the higher pore solution alkalinity and slag reaction extent, the relatively higher carbonation resistance of the AAS mortars is attributed to the lower porosity and average pore size. The loss of compressive strength for the waterglass activated slag mortars after carbonation is due to decalcification of C-A-S-H phase, whereas the carbonation of katoite contributes to the increase of compressive strength of the NaOH activated slag mortars.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Permanent restricted access to Published version, in accordance with the copyright policy of the publisher.
Faculty/School / Institute/Centre: Current - Institute for Advanced Engineering and Space Sciences - Centre for Future Materials
Date Deposited: 23 Jan 2019 06:18
Last Modified: 24 Jan 2019 04:57
Uncontrolled Keywords: alkali-activated cement; carbonation; slag; compressive strength; pore structure
Fields of Research : 09 Engineering > 0912 Materials Engineering > 091202 Composite and Hybrid Materials
Identification Number or DOI: 10.1016/j.cemconres.2018.07.005
URI: http://eprints.usq.edu.au/id/eprint/35284

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