Review of particle- and fiber-reinforced metakaolin-based geopolymer composites

Research on reinforced metakaolin-based geopolymers for structural applications is reviewed. Geopolymers have been synthesized using metakaolin produced from kaolinite extracted from several regional soils. Kaolin is converted into metakaolin by calcination from 650 °C up to 800 °C. To obtain higher strength and stiffness, the geopolymer matrix is reinforced with particles and fibers. In addition, synthetic and natural particles and fibers have been used to enhance durability, thermal properties and shrinkage ratio of lighter geopolymer composites. Owing to the unavailability of a standard for processing and testing geopolymer composites, different laboratories use differing procedures, making data comparison very difficult. The promising market of geopolymer composites for the sustainable construction industry would benefit from a uniform standard for laboratory processing and testing. This would contribute to the creation of a large and reliable data bank, and facilitate the manufacture and certification of geopolymeric sustainable construction materials.