Abstract
The valorisation of industrial solid by-products into geopolymers, a new class of inorganic polymers, provides two main benefits. Firstly, it solves a significant waste management problem by the transformation of potentially dangerous industrial wastes into safe and value-added products. Secondly, it reduces the carbon footprint of cement concrete. Geopolymers exhibit comparable or even improved physico-mechanical and durability properties to those of standard cement-based concrete, with the potential for use in construction applications. Particularly, geopolymers can use alumina-silicate bearing industrial residues, such as fly and bottom ashes, red mud and slags, as secondary raw materials. In the present study, a comprehensive literature review of recent (last five years) advances in the field of sustainable ash-based geopolymers was conducted, focusing on four main types of geopolymers: a) low-Ca siliceous ash-based, b) high-Ca ash-based ones, c) geopolymers from ash-based mixtures, and d) ash-based geopolymer matrix composites.
