Journal of Metals, Materials and Minerals
Publication Date
2021
Abstract
The present study investigated the mechanical and thermal properties of geopolymer composite. The geopolymer composite was prepared by mixing fly ash and wollastonite with the alkaline activator, which was 6 M KOH:K2SiO3 in a mass ratio of 1:1 and a solid:liquid mass ratio of 3:2. The compressive strength at 28 days of geopolymer was 33.3 MPa and possessed the highest strength of 38.3 MPa when 30 wt% wollastonite was added. The flexural strength presented differently whereby it increased from 2.1 MPa to 6.8 MPa. It increased remarkably up to 200% with the addition of 50 wt% wollastonite. The geopolymer composites were exposed to high temperatures at 800℃ to 1100°C for 2 h. Cracks were reduced since 20 wt% wollastonite was added. A high percentage of wollastonite presented excellent thermal stability. The total weight loss of the geopolymer composite at temperatures of 30℃ to 1400°C was minimized. It decreased from 25% to 12% when 50 wt% wollastonite was added, and the dilatometric data resulted in a dimensional change of almost zero. The phase development of the geopolymer composites at high temperatures showed the crystallization of leucite, kalsilite, calcium silicate, calcium aluminium silicate, and calcium aluminium oxide, which were the high temperature stable phases. The results indicated that wollastonite reinforced fly ash-based geopolymer composites are promising for use in high temperature applications.
DOI
10.55713/jmmm.v31i4.1230
First Page
13
Last Page
25
Recommended Citation
Hemra, Khanthima; Kobayashi, Takaomi; Aungkavattana, Pavadee; and Jiemsirilers, Sirithan
(2021)
"Enhanced mechanical and thermal properties of fly ash-based geopolymer composites by wollastonite reinforcement,"
Journal of Metals, Materials and Minerals: Vol. 31:
No.
4, Article 2.
DOI: 10.55713/jmmm.v31i4.1230
Available at:
https://digital.car.chula.ac.th/jmmm/vol31/iss4/2