Evaluation of GFRP Reinforced Circular Geopolymer Concrete Columns Under Concentric and Eccentric Axial Loading

This study presents an experimental investigation to evaluate the behavior of circular geopolymer concrete columns reinforced with Glass Fiber Reinforced Polymer (GFRP) bars and helices under axial compression. Four circular geopolymer concrete columns of 160 mm diameter and 640 mm height were tested under concentric and eccentric axial loading. Two columns were reinforced with longitudinal steel bars and steel helices and two columns were reinforced with longitudinal GFRP bars and GFRP helices. The influence of the type of internal reinforcement and the axial loading eccentricity were investigated. The GFRP bar reinforced columns achieved lower axial load-carrying capacity than the steel bar reinforced columns under both concentric and 35 mm eccentric axial loadings. The axial load carrying capacity of concentrically loaded GFRP bar reinforced column was 15% less than the axial load carrying capacity of steel bar reinforced column. However, the axial load carrying capacity of eccentrically loaded GFRP bar reinforced column was only 5% less than the axial load carrying capacity of steel bar reinforced column. The ductility of concentric and 35 mm eccentric axially loaded GFRP bar reinforced columns were about 42% and 7% less, respectively than the ductility of their steel counterpart