The effect of aggregate type on geopolymer concrete high temperature resistance

Concrete is the most used building material in the world. However, during producing cement, a high amount of energy is consumed, and excessive carbon dioxide emissions are made. The production of alternative binders to the Portland cement has been studied for a long time. Geopolymers are materials that have the potential to be an alternative to the cement. It is well-known that geopolymers have a good high temperature resistance. However, the high temperature resistance of both conventional and geopolymer concretes is significantly affected by the type and properties of the aggregate. In this study, the resistance of geopolymer concretes produced by using limestone, river, basalt and slag aggregates to 600 and 900 degrees C temperatures was determined by comparing their compressive strength losses. The geopolymer concrete produced with limestone aggregate was completely decomposed up on exposure to 900 degrees C. However, the counterpart concretes produced with river, basalt and slag aggregates lost 32.9, 48.5 and 53.6% of their compressive strength, respectively.