Empirical Relationships on Mechanical Properties of Class-F Fly Ash and GGBS Based Geopolymer Concrete

Ordinary Portland Cement (OPC) is one of the important materials used in the development of the construction industry.Production of OPC consumes lot of raw materials, emits extreme quantity of carbon dioxide (CO2) into atmosphere and highly energy-intensive.Thus, to reduce the production of cement so many attempts are done and an alternative binder was found.The alternative to cement concrete is geopolymer concrete (GC) and it is produced by mixing industrial by-products (rich in aluminosilicate) with an alkaline solution.This paper explores the mechanical properties and a representative non-linear equation was proposed for the relationship between splitting tensile Vs compressive strengths and flexural Vs compressive strengths of fly ash-GGBS synthesized GC cured at ambient temperature for 28 days.This work also presents empirical formulae for predicting elastic modulus of fly ash-GGBS synthesized GC.Equations were proposed to determine the splitting tensile strength, flexural strength and elastic modulus based on the compressive strength of GC.The obtained results are clearly indicating that the predicted (from proposed equations) splitting tensile and flexural strength values are very close to the experimental values.It is established that the formulae found in various codes and literature generally predict the higher values of the elastic modulus than those obtained using the proposed equation.