Ductility Index For Class F Fly Ash Based Reinforced Geopolymer Concrete Beams

Abstract

This paper presents the experimental investigation on low calcium class F based reinforced geopolymer concrete beams, cast for different percentage of tension reinforcement, with varying molarities of sodium hydroxide and ratio of sodium silicate to sodium hydroxide solution. The preliminary investigation on compressive strength, split tensile strength and flexural strength were carried out to assure that geopolymer concreter behaves like conventional cement concrete. Sixteen reinforced geopolymer concrete beams were cast to study the ductility behaviour of reinforced geopolymer concrete beams by varying the percentage of tension reinforcement. The test results of reinforced geopolymer concrete were validated with respect to load-deflection characteristics of the reinforced geopolymer concrete beams and ductility in accordance with the provisions given in Indian standard code IS: 456-2000 for reinforced Portland cement concrete. The ductility indices calculated for the reinforced geopolymer concrete beams in the present investigation have clearly shown that the acceptable lower bound of ductility index is ensured for moment redistribution, at the limit state of serviceability. The crack propagation observed for the reinforced geopolymer concrete beams is very similar to that obtained in reinforced cement concrete beams