Fire resistance of fly ash-based geopolymer concrete blended with calcium aluminate cement

![CDATA[Geopolymer has been known as an eco-friendly alternative to Portland cement-based concrete. Geopolymer concrete usually uses alkali-activated fly ash as the binder, and develops desirable strength within 8 hours when a heat-curing regime is used. Due to its ceramic-like properties, geopolymer concrete is believed to have high fire resistance. When heat-cured geopolymer concrete is exposed to high temperatures, a strength gain is often reported. However, the heat-curing procedure limits the future of geopolymers for on-site applications. To solve this issue, suitable additives (e.g., ground granulated blastfurnace slag and calcium aluminate cement) can be used in the binder which can develop the desirable strength of geopolymer concrete. It is important to understand the high-temperature performance of ambient-cured geopolymer concretes which have received little attention. This paper presents a study on the high-temperature performance of fly ash-based geopolymer concrete cured at ambient temperature. Compression tests were carried out on geopolymer mortars at temperatures of 23, 600 and 800̊C. As an outcome from this work, the authors have proposed a geopolymer concrete mixing design based on the parameter analysis, and the fire performance of the geopolymer concrete are compared with that of the reference OPC concrete at different temperatures.]]