An Investigation On Geopolymer Concrete: A Review

Abstract

In the world of concrete, where cement is the main constituent, there is a new development named as Geopolymer concrete (GPC). In Geopolymer concrete, the cement is totally replaced by pozzolanic materials like fly ash or ground granulated blast furnace slag. The Geopolymer concrete uses highly alkaline activators to act as binder for the concrete. An experimental investigation has been carried out in order to find the suitable ingredients of the Geopolymer concrete and mix design procedure is proposed to achieve the desired strength at required workability. The fly ash, being waste is disposed and hence poses an environment threat. Also for reducing the cement consumption, effective promotion of Geopolymer concrete is required. And hence, mix design procedure for production of Geopolymer concrete is essential. Therefore, efforts have been made in order to develop a mix design methodology for Geopolymer concrete with the main objective on achieving better compressive strength in an economical way.  Fly ash of Class F is used as a binder material for this study, which was brought from local sources. Based on the investigation carried out, sodium hydroxide and sodium silicate are taken as alkaline activator solutions. To achieve the compressive strength in an economical way, correlation between alkaline activator solution molarity and 28 days compressive strength has been investigated for the advancement of conceptual mix design method for Geopolymer concrete. The proposition of mix design includes various molarities of alkaline activator solution ranging from 12 to 16 M and the 28 day compressive strength has been calculated. The proposed design methodology has been given step wise and its verification is given with the help of example in this research. Geopolymer concrete consists of broader range of constituents and therefore for obtaining the best strength of Geopolymer mix, numerous trial mixes are required. In this research, strength criterion mix design is proposed in an economical way, considering all primary constituents and their proportions. The tests for workability, compressive strength and durability are included in this research.