A STUDY ON SYNTHESIS AND GEOPOLYMERIZATION KINETICS OF FLY ASH BASED GEOPOLYMER

Geopolymers are versatile materials possessing properties superior to conventional
materials as well as potential of use in a variety of applications. Geopolymerization is
a multistep process involving many reactions occurring concurrently. Despite several
kinetics studies, the geopolymerization kinetics of fly ash based geopolymers and the
mechanism involved during its formation has not been well understood. This research
determines the geopolymerization kinetics of fly ash based geopolymer using Johnson-
-MKhl-Avrami-TCnlmngnrnv (TMAK) mndH and r.harartpriyatinn techniques. The
geopolymer formation with time was measured in terms of degree of reaction of fly ash
(a) by hydrochloric acid (HC1) method. Four synthesis parameters such as silica to
alumina ratio (Si/AI) ratio (1.8-2.6), sodium to alumina (Na/Al) ratio (1-1.4), water to
solid (W/S) ratio (0.2-0.3), and curing temperature (40-80°C) were selected to
determine their effects on setting time, compressive strength, and degree of reaction
(a). The geopolymer samples were designed using Taguchi statistical design method.