Experimental and numerical investigation on the behavior of hybrid concrete beams reinforced with GFRP bars after exposure to elevated temperature

Abstract

This study puts forward experimental and numerical investigations to understand the response and failure of hybrid concrete beams reinforced by Glass Fibre Reinforced Polymer (GFRP) bars and exposed to elevated temperature. Seven GFRP reinforced hybrid concrete beam specimens were designed according to ACI440.1R-15 (ACI, 2015) and exposed to temperature values between 300 °C and 700 °C and subjected to monolithically increased static load up to failure. The effects of elevated temperature on load- displacement relationships and failure modes were evaluated and discussed. Experimental results have indicated that shear failure is the predominate failure mode of all tested beams. Results have also shown that the maximum reduction in the ultimate load capacity of the hybrid concrete GFRP reinforced concrete beam is about 53% when exposed to temperature value of 700 °C compared with the ultimate load capacity of the beam at ambient temperature.This paper also suggests and validates a numerical model to simulate the performance and failure of GFRP reinforced hybrid concrete beams under high temperature using the finite element software ABAQUS. The numerical model was firstly verified against the experimental test results and then used to investigate the effect of several important parameters on the performance and ultimate load of GFRP-RC beams under different elevated temperatures.