Effect of Metakaolin in the Mechanical Properties of Ambient Cured Flyash Based Geopolymer Concrete

Cement is one of the most versatile construction material used worldwide. But cement industry is responsible for several environmental issues like global warming. To address these issues there is a need for alternative binders to substitute cement. Geopolymer concrete (cement less concrete) is found to be a better alternative to conventional concrete. Geopolymer concrete (GPC) utilizes the cementitious properties of industrial byproducts like flyash, silicafume, GGBS etc. Flyash based geopolymer concrete is the common type of GPC. Flyash based GPC requires heat curing and is suitable only for precast members. Development of GPC which does not require heat curing will widen its application. This work aims to study the effect of metakaolin on the properties of ambient cured flyash based GPC. Experimental investigation is carried out by replacing flyash by metakaolin in varying percentages of 20, 30, 40, 50 and 60%. It was observed that ambient cured flyash-metakaolin GPC possess characteristics suitable for structural applications. The mechanical properties of GPC increased with increase in metakaolin content while workability properties showed a slight reduction.