Open AccessMicrostructural Analysis of Fly Ash-based Geopolymers with various Alkali Concentration
Author(s) -
Ng Hui-Teng,
Heah Cheng-Yong,
Liew Yun-Ming,
Mohd Mustafa Al Bakri Abdullah,
Ng Yong-Sing
Publication year - 2019
Publication title -
iop conference series. materials science and engineering
Language(s) - English
Resource type - Journals
eISSN - 1757-899X
pISSN - 1757-8981
DOI - 10.1088/1757-899x/551/1/012090
Subject(s) - fly ash , geopolymer , sodium silicate , sodium hydroxide , alkali metal , materials science , silicate , sodium , chemical engineering , microstructure , nuclear chemistry , composite material , chemistry , metallurgy , organic chemistry , engineering
In the present work, a comparative study on the effect of different concentration of sodium hydroxide (NaOH) on fly ash-based geopolymer was investigated. The geopolymer synthesis by mixing fly ash with alkali activator (a mixture of NaOH and sodium silicate) at solid/liquid ratio of 2.5. The NaOH were used 6M, 8M, 10M, 12M and 14M with constant sodium silicate/NaOH ratio of 2.5. The geopolymers were cured at room temperature (29°C) for 24 hours and 60°C in oven for another 24 hours. The testing and analysis of the fly ash-based geopolymers were performed after 28 days. The adequate Na + ions and densified microstructure were observed at optimum 8M-NaOH-activated fly ash-based geopolymers.