Experimental Study on Residual Flexural Behavior of Reinforced Concrete Beams after Exposure to Fire

Abstract

Reinforced Concrete (RC) beams in the building structures are usually assumed as a ‘T’-shaped beam when the effects of adjacent slab flange are considered. However, experimental studies on residual flexural behavior of ‘T’-shaped RC beams are rarely reported. The residual flexural behavior of two RC rectangular beams and one RC ‘T’-shaped beam after exposure to ISO834 standard fire were experimentally investigated in the paper. The detailed experimental results, including the measured temperatures, flexural capacity, load-deflection curves and concrete strain are presented. The effects of flange on temperature distribution and residual flexural behavior of RC beams were analyzed. The experimental results show that: (a) the assumption of plane section is applicable for RC ‘T’-shaped beam. (b) The flexural capacity of RC rectangular beam was decreased 18.5% after exposure to fire for 2 hours, but the ultimate mid-span deflection was increased 55.1%. (c) The residual flexural capacity and the ultimate mid-span deflection of RC rectangular beam after fire was respectively increased 8.4% and 9.9% due to the effect of flange.

Characterization of bending performance of reinforced cementitious composites beams with hybrid fibers after exposure to high temperatures

“…The reason was that after high temperature and cooling, the strength of longitudinal steel bars under stress recovered to a large extent, while the strength of concrete further decreased. So the shear strength of reinforced beam was significantly decreased 39 . As a result, the bending failure was changed to shear failure after high temperature.…”

“…So the shear strength of reinforced beam was significantly decreased. 39 As a result, the bending failure was changed to shear failure after high temperature. HyFRCC can be used as concrete material in fire resistance engineering.…”

Applicability of the 500°C isotherm method in determining the strength of reinforced concrete beams after fire

“…Xu et al [19]- [21] presented experimental studies analyzing the residual strength after fire to shear and the bending moment of reinforced concrete beams with rectangular and "T" sections. In Xu et al [20] a study on estimating of the resistance after fire is presented based on the Chinese code [22], reducing the strengths of concrete and steel as a function of temperature.…”

Residual response of fire‐damaged high‐strength concrete beams

“…At present, postfire residual behavior of reinforced concrete (RC) structural members is still not well established. There are limited experimental and numerical studies on residual behavior of fire‐exposed NSC beams, with much fewer studies on HSC beams. In previously reported studies, a standard fire (heating) regime was mostly adopted for simulating fire damage in the beams, without any consideration to cooling phase, which is an important consideration for realistic fires in building compartments.…”