Rosnita Mohamed, Rafiza Abd Razak, Mohd Mustafa Al Bakri Abdullah, Raa Khimi Shuib, Subaer, Jitrin Chaiprapa
The main objective in this study is to elucidate the geopolymerization of Class C fly ash at different solid-to-liquid ratio (1.0-3.0) by using heat evolution analysis. Differential Scanning Calorimeter was used to monitor heat evolution. The calculated heat evolved was utilized to analyze the reaction kinetics using Johnson-Mehl-Avrami-Kolmogrov Model and correlate with the compressive strength and microstructural properties encompassing morphology, functional group, phase analysis, and elemental distribution. The heat evolution was found to increase with increasing solid-to-liquid ratios. The nucleation mechanism of geopolymerization of Class C fly ash was governed by instantaneous heterogeneous nucleation with rod-like growth. Solid-to-liquid ratio of 2.5 was concluded as optimal ratio due to its great performance for strength development. Meanwhile the contribution of calcium (Ca) and iron (Fe) was confirmed due to the presence of Si-O-Ca and Si-O-Fe bonds in the functional group analysis, which was further confirmed by phase analysis and elemental distribution mapping. © 2020
Geopolymer & Green Technology, Centre of Excellence (CEGeoGTech), Universiti Malaysia Perlis (UniMAP), Perlis, Malaysia; Faculty of Civil Engineering Technology, Universiti Malaysia Perlis (UniMAP), Perlis, Malaysia; School of Materials & Minerals Resources Engineering, Universiti Sains Malaysia, Nibong Tebal, 14300, Pulau Pinang, Malaysia; Geopolymers & Green Material Group, Physics Department, FMIPA, Universitas Negeri Makassar, Indonesia; Synchrotron Light Research Institute, Muang, Nakhon Ratchasima, 3000, Thailand
