Quantification of chloride diffusion in fly ash-slag-based geopolymers by X-ray fluorescence (XRF)

Yang, Tao and Yao, Xiao and Zhang, Zuhua (2014) Quantification of chloride diffusion in fly ash-slag-based geopolymers by X-ray fluorescence (XRF). Construction and Building Materials, 69. pp. 109-115. ISSN 0950-0618

Abstract

Chloride diffusion in cementitious materials is one of the key factors affecting the durability performance of concretes. This paper reports an investigation on the quantification of chloride diffusion in fly ash-slag-based geopolymer pastes. X-ray fluorescence (XRF) technique was used to determine the chemical compositions of the samples after short-term ponding test (contact with the 3% NaCl solution for 72h). The effect of the coexistence of Al-substituted calcium silicate hydrate (C-A-S-H) gel and aluminosilicate geopolymeric gel on the ingress of chloride was evaluated. The results showed that incorporation of slag as a secondary precursor in fly ash-based geopolymers led to the refinement of the pore structure, reducing both sorptivity of the pastes and the ingress of chloride ions. More compact C-A-S-H gel formed in geopolymer pastes with partial slag substitution led to lower permeability compared with the porous aluminosilicate gel that formed in the full fly ash-based geopolymer paste, contributing to the slower transportation of chloride in the fly ash-slag blended geopolymer pastes. The fly ash-slag-based geopolymer paste with 50% of slag performed better than the Portland cement paste in terms of resistance to chloride ingress.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: © 2014 Elsevier Ltd. Permanent restricted access to published version in accordance with the copyright policy of the publisher.
Faculty / Department / School: Current - Faculty of Health, Engineering and Sciences - No Department
Date Deposited: 25 Aug 2014 22:50
Last Modified: 04 Jul 2016 23:00
Uncontrolled Keywords: chloride diffusion; durability; fly ash; geopolymer; pore structure; slag
Fields of Research : 09 Engineering > 0905 Civil Engineering > 090503 Construction Materials
03 Chemical Sciences > 0303 Macromolecular and Materials Chemistry > 030305 Polymerisation Mechanisms
09 Engineering > 0912 Materials Engineering > 091209 Polymers and Plastics
Socio-Economic Objective: B Economic Development > 87 Construction > 8703 Construction Materials Performance and Processes > 870301 Cement and Concrete Materials
Identification Number or DOI: 10.1016/j.conbuildmat.2014.07.031
URI: http://eprints.usq.edu.au/id/eprint/25833

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