Fabrication and engineering properties of concretes based on geopolymers/alkali-activated binders - A review

Concretes based on geopolymers/alkali-activated binders have attracted considerable attention as the promising construction and repair materials since their discovery because of their superior properties. Moreover, less pollution was caused by geopolymer/alkali-activated concretes than conventional cement concretes. In this paper, 173 investigations reported in related literatures are integrated, and a comprehensive review on the fabrication and engineering properties of a variety of geopolymer/alkali-activated concretes is presented. The following details are included: probable source materials, alkaline activator requirements, curing conditions, compressive strength, elastic performance, tensile strength, flexural strength, fracture performance, bonding strength between geopolymer/alkali-activated concrete and steel bars, high temperature resistance, abrasion resistance, porosity and water absorption, frost resistance, chemical attack resistance, drying shrinkage, and carbonation resistance. Existing studies have revealed the excellent mechanical properties and extraordinary durability of geopolymer/alkali-activated concretes and predicted their broad application prospect in the engineering field. However, the current research status reveals that more investigations related to feasible and economical mix proportions, with which the geopolymer/alkali-activated concrete could exhibit the best engineering properties, are required.