The Potential of Geopolymer in Development of Green Coating Materials: A Review

Cementitious coating is essential as passive protection for building and infrastructure including steel and coastal structures from aggressive environment, such as fire and chloride and enhance the durability of the substrate. Still, there is durability concern on the conventional ordinary Portland cement (OPC)-based coatings that will lead to high repair cost. The durability concern is normally caused by weathering effects, UV degradation, fire and toxicity. In recent years, researches on the incorporation of geopolymers as cementitious coating materials have been growing, considering its superior performance in durability and mechanical strength over the conventional OPC-based coatings, especially the long-term durability and under aggressive environment. The present review summarizes the potential use of geopolymers as green coating materials, where the performance in terms of strength, durability such as fire resistance, heat resistance and corrosion resistance, as well as the influencing factors and prospects are discussed. This review concludes with an outline of some future opportunities, in view of environment protection, engineering applications and economic savings.