Please use this identifier to cite or link to this item: https://hdl.handle.net/10356/142400
Title: Effect of alkali cation type on strength endurance of fly ash geopolymers subject to high temperature exposure
Authors: Lahoti, Mukund
Wong, Keng Khang
Tan, Kang Hai
Yang, En-Hua
Keywords: Engineering::Civil engineering
Issue Date: 2018
Source: Lahoti, M., Wong, K. K., Tan, K. H., & Yang, E.-H. (2018). Effect of alkali cation type on strength endurance of fly ash geopolymers subject to high temperature exposure. Materials and Design, 154, 8-19. doi:10.1016/j.matdes.2018.05.023
Journal: Materials and Design
Abstract: Choice of alkali cation in mix design of geopolymers is critical for their thermal performance. However, the influence of alkali cation type on strength endurance of geopolymers subject to high temperature exposure and the underlying governing mechanisms have not been studied. This study investigated the effects of alkali cation type on high temperature response of fly ash geopolymers aiming towards structural applications. In-depth investigation was carried out to discover the underlying mechanisms governing the strength endurance of fly ash geopolymers subject to high temperature exposure and its correlation with their volume stability and chemical stability. Results showed that potassium geopolymer exhibited significant strength enhancement (30–40%) and sodium geopolymer displayed reduced strength (10%), and the strength of mixed sodium and potassium geopolymer remained unchanged after exposure to elevated temperature. While the binders were chemically stable without deterioration and formation of new crystal phases after high temperature exposure, the volume stability varied with the type of alkali cation used. Formation of cracks and gel densification due to shrinkage, and healing of micro-cracks and change of pore sizes due to sintering were identified as responsible mechanisms at different temperature ranges. While crack development and enlargement of pores lowered the strength, densification of matrix and healing of micro-cracks favored strength gain. These competing mechanisms determine the strength endurance of geopolymers depending on the type of alkali cation used. Overall, it shows that geopolymers can be tailored, such that stable (or even enhanced) strengths upon thermal exposure are realized, for structural applications.
URI: https://hdl.handle.net/10356/142400
ISSN: 0261-3069
DOI: 10.1016/j.matdes.2018.05.023
Rights: © 2018 Elsevier Ltd. All rights reserved.
Fulltext Permission: none
Fulltext Availability: No Fulltext
Appears in Collections:CEE Journal Articles

SCOPUSTM   
Citations 10

20
Updated on Mar 10, 2021

PublonsTM
Citations 20

14
Updated on Mar 7, 2021

Page view(s)

58
Updated on Dec 4, 2021

Google ScholarTM

Check

Altmetric


Plumx

Items in DR-NTU are protected by copyright, with all rights reserved, unless otherwise indicated.