High temperature effect on structure formation and performance of hybrid geopolymers

Abstract

Fly ash based hybrid geopolymers (HGP) containing different type of mineral admixtures such as portland cement (PC), kaolin and metakaolin (MK) were developed in this study. The improved values of compressive strength, water absorption and water resistance for PC-modified hybrid geopolymers versus MK-modified HGP and reference mix was observed. High-temperature treatment (600 °C) enables to boost compressive strength by 177 % and 55 % as well as water resistance by 34 % and 40 % for MK-modified and kaolin modified HGP, respectively. At the same time, the PC-modified HGP demonstrated a very low thermal resistance, which was confirmed by a rapid drop of compressive strength and distracted structure of the specimen subjected to high temperature.