A state of the art on effect of alkali activator, precursor, and fibers on properties of geopolymer composites

Engineered geopolymer composites (EGC) are a new type of high-performance fiber-reinforced geopolymer composites with improved tensile, flexural, and strain hardening properties. This review article aims to provide an all-encompassing overview on the effect of various factors such as the addition of alkali activators, their chemistry, reaction mechanism, precursors, admixtures, and fibers in hybrid combination on the engineering properties of EGC. Among these, the alkali activator solution plays a crucial role in the geopolymer formulation and its binding capacity. From the review articles, it was found that EGC have higher strain-hardening capacities of about 4–7 % and improved mechanical properties due to enhanced geopolymerization and strong interfacial bond between the fibers and the matrix. The research gap in EGC pertaining to use of low and high-modulus fibers in hybrid combinations, durability, carbonation, and corrosion studies should form the focus of future research. [Display omitted] •SHGC shows enhanced tensile strain hardening behavior.•SHGC exhibits better deflection and multiple cracking behavior during bending.•EGC displays better compressive strength compared to ECC.