Nanomaterials Applied in Modifications of Geopolymer Composites: a Review

Following the recognition of the enormous impact of cement industry on the environment, a large number of studies have recently been undertaken in the search for an environmentally friendly alternative to Ordinary Portland Cement (OPC). Among those considered, geopolymer, where OPC is replaced with alkali-activated binders, has a shown significant potential for use as an alternative binder in concrete. However, owing to their inherent weakness, particularly ambiently-cured geopolymer, the use of such a material remains limited in structural applications. In recent years, nanotechnology, which is a cutting-edge science, has been gradually introduced into the research for civil structural engineering applications and has been recognised as a feasible technique to improve the properties of geopolymer. A number of recent studies have reported the behaviour of geopolymer-containing nano-materials. This paper summarises all the published literature on this topic until 2016 and provides an all-encompassing review of the existing reports discussing the methods of using nano-materials in geopolymer and the properties of geopolymer-containing nano-materials.