Durability of geopolymers and geopolymer concretes: A review

Abstract

Geopolymers are green materials with three-dimensional silicon and aluminum tetrahedral structures that can be serving as environmentally friendly construction materials and therefore have the potential to contribute to sustainable development. In this paper, the mechanism and research progress regarding the carbonation resistance, structural fire resistance, corrosion resistance, permeation properties and frost resistance of geopolymer concretes are reviewed, and the main problems with the durability of geopolymer concretes are discussed. Geopolymers possess the superb mechanic property and their compression strengths could be higher than 100 MPa. Generally, the higher the GPC strength, the better the carbonation-resistant. GPC has excellent fire resistance, due to geopolymers are acquired an inorganic skeleton which is affected by the alkali content, alkali cation, and Si/Ai ratio. There are a large number of Al-O and Si-O structures in geopolymers. Geopolymers do not react with acids at room temperature and can be used to make acid-resistant materials. Besides, GPC owning low porosity volume shows good resistance to permeability. The freezing-thawing failure mechanism of geopolymer concretes is mainly based on hydrostatic and osmotic pressure theory. GPC has poor frost resistance, and the freezing-thawing limit is less than 75 times.