Porosity and fire resistance of fly ash based geopolymer

The fly ash based geopolymer (fa-gp) is a promising binder manufactured by activation of jorf lasfer's fly ash with a highly alkaline activating solution. the fa-gp prepared were characterized by several analytical methods. the present work reports the experimental results of the porosity and fire resistance studies of fly ash based geopolymer fa-gp binder and ordinary portland cement (opc) cement for comparison. the porosity studies of fa-gp and opc cement pastes were determined using n2 adsorption/desorption plots. surface areas were calculated from the isotherm data using the (bet) method. the total pore volume and micropore volume of the samples were calculated using t-plot analysis. the barrett-joyner-halenda (bjh) method was used to obtain pore size distribution curves. the result shows that the fa-gp pores had a significant proportion of micropores whilst opc cement pores were predominantly mesopores. the thermal and fire resistance properties were determined by investigation of thermal stability up to 1000°c of fa-gp and opc paste for comparison. the effect of heat treatment on the fa-gp and opc pastes heated at elevated temperature (600°c,800°c and 1000°c) was studied and the fire resistance of samples pastes is evaluated by visual observation,weight loss,and microstructural change after thermal treatment at high temperature. the microstructural changes before and after heat exposure were evaluated using ft-ir,drx and sem analysis. the results show that the fa-gp possesses superior fire resistance compared to opc cement. the excellent fire resistance performance of fa-gp is due to their ceramic-like characteristics. © 2017,university of mohammed premier oujda morocco.