Abstract: In this paper , based on the experimental data , with the help of "Jander"kinetic equation and modern analytical methods , the reaction kinetics of fly ash geopolymer system were studied .The research content include:the effect of liquid-solid ratio on the reaction process , the reaction kinetics stage of fly ash based geopolymer , the effects of temperature and alkali concentration on the each reaction kinetics stage and generating mechanism of compressive strength .The results show that:Reducing liquid-solid ratio will cause a decline in the reaction rate , promote the formation of solid products and the structure change of reaction products .The main reaction kinetics stage belong to diffusion reaction stage ( model N=2 and N>2).Increasing temperature can improve each reaction rate and at same time reduce stage duration of each kinetics stage .Higher alkali concentration could effectively increase the reaction rate of each kinetics stage.The difference of chemical composition between fly ash particles and reaction produces is related to the geopolymer reaction process and the formation of compressive strength .

Key words: fly ash;geopolymer;kinetics