Characterisation of “One-part” Ambient Cured Engineered Geopolymer Composites

Abstract

Engineered geopolymer composites (EGC) recently emerged as a promising alternative to resolve traditional concrete’s CO2 emission and brittleness. It features a cementless-based solution and possesses pseudo-strain-hardening (PSH) behaviour with high tensile ductility. There are two main obstacles associated with the use of geopolymer: firstly, the handling of user-hostile alkaline solutions and secondly, the necessity of heat curing. This paper aims to summarize the findings on the development and characterization of an ambient cured “one-part” EGC under the influence of various parameters, namely binder proportion between fly ash (FA) and ground granulated blast furnace slag (GGBS), quartz powder/binder ratio, alkali activator/binder ratio and water/binder ratio. Fresh and mechanical properties consisting of compressive strength, uniaxial tensile performance, and microstructure analysis were conducted. The results obtained indicate that increased FA content favours the attainment of PSH behaviour of the composite due to low matrix fracture toughness and fibre-matrix interfacial bond strength. Low water content and increased alkali activator content would greatly enhance the matrix toughness and fibre-matrix interfacial bond strength. The addition of quartz powder may favour strength attainment, but excessive quantities may have unfavourable consequences on the PSH behaviour.