Quantifying the Effect of Temperature Induced Bond Degradation on Fire Resistance of RC Beams

Abstract

This paper presents the effect of temperature induced bond degradation on fire resistance of reinforced concrete (RC) beams. Results from experimental and numerical studies, both at material and structural level, on temperature induced bond degradation in RC beams are presented. As part of material level tests, high temperature double tension pull-out (DTP) tests on normal strength concrete (NSC) and high strength concrete (HSC) specimens were conducted in a customized setup to ensure presence of longitudinal tensile stress in concrete surrounding the ribs. Data from tests is utilized to propose a simplified temperature dependent bi-linear bond stress-slip relationship. Furthermore, a finite element based numerical model is developed in ABAQUS that accounts for temperature induced bond degradation in evaluating response of RC beams under fire conditions. The model is applied to quantify the effect of temperature induced bond degradation on fire resistance of RC beams.