Strength properties of Fly Ash based Geopolymer Concrete cured at different temperatures

Abstract

This paper presents the results of an experimental study of the effect of curing temperature on the compressive strength and split tensile strength of Geopolymer concrete (GPC) which is made using fly ash produced at Norochcholai Coal Power Plant, Sri Lanka. A relationship between splitting tensile strength and compressive strength is also developed using test data. The results are then compared with some expressions published in international literature. A mixture of Sodium Silicate and Sodium Hydroxide solutions was used to activate low calcium class F fly ash to form Geopolymers. All specimens were oven cured for 48hours where curing temperature was varied from ambient temperature to 80oC at 20oC intervals. One day of rest period was given to every sample before curing. Test results showed that curing temperature has a significant effect on rate of strength gaining of GPC. The output of this study has provided a better understanding of the correlation between splitting and compressive strengths of GPC, which has therefore helped to generate a new expression with better accuracy for GPC prepared using locally available fly ash.