Open AccessThermal Exposure of Fly Ash-Metakaolin Blend Geopolymer with Addition of Monoaluminum Phosphate (MAP)
Author(s) -
Khairunnisa Zulkifly,
Heah Cheng-Yong,
Mohd Mustafa Al Bakri Abdullah,
Hussin Kamarudin
Publication year - 2020
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/864/1/012011
Subject(s) - geopolymer , metakaolin , compressive strength , materials science , aluminosilicate , microstructure , fly ash , composite material , curing (chemistry) , chemistry , organic chemistry , catalysis
Recent research reveals that formulation of blended geopolymers based on the association of two aluminosilicate precursors had a better performance than one precursor geopolymers. This study presents a facile method to enhance the compressive strength of fly ash-metakaolin blend geopolymer by incorporating monoaluminum phosphate (MAP) during the geopolymerization reaction. The effect of the thermal exposure on the microstructure and compressive strength of the geopolymer are investigated. Results show that the MAP is transformed to granule structures, bonded and surrounded by geopolymer gel. The unique microstructure increases the compressive strength of the room temperature curing geopolymer from 54.7 MPa to 64.21 MPa (14.8%) with an optimum addition of 1.0 wt% MAP. This enhancement in compressive strength was ensured by the formation of an amorphous structure of aluminosilicophosphate (SiO 2 .Al 2 O 3 .P 2 O 5 .nH 2 O) phase. At higher temperatures, the formation of stable crystalline phase of berlinite and nepheline contribute to strength retention of the geopolymer. Hereby, it can be concluded that the addition of 1.0wt% MAP in the geopolymer reinforced the structure.