Compressive Strength and Thermal Expansion Properties of Geopolymer Concrete at Elevated Temperature

Abstract

This paper presents the results of an experimental study on the effect of elevated temperature up to 800°C on the compressive strength and thermal expansion of geopolymer concrete. The effects of molarity of alkali activator and curing conditions on the compressive strength of geopolymer concrete at elevated temperature up to 800°C are also studied. The results show that, the geopolymer concrete gained between 10% and 50% of its ambient strength after exposure to 800°C temperature, compared to 80% loss of OPC concrete. Geopolymer concrete exhibited about 10% less strain to that of OPC concrete mix containing same aggregates. Geopolymer concrete with low molarity (10 Molars) benefited with significant strength gain whereas geopolymer concrete with high molarity (16 Molars) only attained minor increase in strength at elevated temperatures above 400°C. The same is true when geopolymer concrete was cured for a longer duration.