BEHAVIOUR OF CONCRETE SHORT COLUMNS WITH GFRP REINFORCEMENTS

The need for evaluating the strength of short columns is felt necessary as these columns are susceptible to fail under lateral loads due to seismic loads. In this experimental work, nine short concrete columns reinforced with Glass Fiber Reinforced Plastic (GFRP) main bars and helical stirrups were tested. The reinforcements were fabricated in-house by using a simple semi-mechanized technique. While keeping the amount of column main reinforcement constant for the all the specimens, the pitch of the spiral reinforcement and grade of concrete were varied to investigate the short concrete columns. The pitch distances adopted were 75 mm, 100 mm, and 150 mm and the grades of concrete were M 20, M 30 and M 40 respectively. A slenderness ratio of 4.66 was kept constant for all the columns. Strain gauges were used to determine the strains developed in concrete and GFRP reinforcements due to the applied load. The short column specimens were subjected to testing under pure axial load condition to evaluate the compressive load carrying capacity of these columns.