Fibre-reinforced geopolymer concrete with ambient curing for in situ applications

Geopolymer concrete is proven to have excellent engineering properties with a reduced carbon footprint. It not only reduces the greenhouse gas emissions (compared to Portland cement-based concrete) but also utilises a large amount of industrial waste materials such as fly ash and slag. Due to these positive attributes, it is becoming an increasingly popular construction material. Previous studies on geopolymer concrete report that heat curing plays an important role in gaining higher compressive strength values (as opposed to ambient curing), and hence the application of this material could be limited to precast members. Therefore, this research was aimed at investigating the effect of heat curing by comparing the mechanical properties such as compressive strength and ductility of ambient cured and heat cured geopolymer concrete samples. It is worth noting that there was marginal strength change due to heat curing. In Australia, fibre-reinforced geopolymer concrete is being used in precast panels in underground constructions. Commercially available geopolymer cement and synthetic fibres are effectively being used to produce elements that are more durable than what is currently used in industry. As a result, this research investigated the effects of polypropylene fibres in geopolymer concrete using 0.05 and 0.15 % fibres (by weight). The addition of polypropylene fibres enhances the compressive strength and the ductility of geopolymer concrete.