Performance of GFRP reinforced HPC compression members under axial loading

Abstract

Performance of GFRP reinforced HPC compression members under axial loading were studied by conducting detailed experimental investigations. Basic properties of constituents of HPC were studied and concrete mix design was done using IS code method. For the present study, twenty-four columns of size 150 mm x 150 mm and slenderness ratios of 6, 8, 10 and 12 were cast with length of column 900 mm, 1200 mm, 1500 mm and 1800 mm respectively, in which twelve columns are GFRP reinforced and other twelve are steel reinforced. For each slenderness ratio, three different percentages of reinforcement was tried with 1.4%, 2% and 3.5% with diameter of bars as 10 mm, 12 mm and 16 mm longitudinal reinforcement both in GFRP and steel. Performance characteristics such as load carrying capacity, axial deformation, lateral deformation and axial strain of rebars were studied in detail. Parametric study was done by taking L/D ratio and percentage of reinforcement as parameters. Experiments were performed with 2000 kN capacity loading frame. Strain gauges were fitted with reinforcement to measure rebar strain. Axial and lateral deformation of HPC square columns were measured using LVDTs. Lateral deformation was measured by keeping 5 LVDTs at every L/6 interval. The loads were applied with an increment 10 kN through hydraulic jack and deformations were measured upto a load of 500 kN for safety purpose and to maintain uniformity for comparison purpose and all the columns tested upto failure stage. The validation of experimental results was done with the results of Finite Element Model developed using ANSYS software. newline