Influence of reinforcement corrosion on fire performance of reinforced concrete beams

Abstract

Abstract Corroded steel bars frequently exist in concrete structures under chloride exposure conditions; moreover, corroded reinforced concrete (RC) is not fireproof. This paper presents an investigation on the effects of reinforcement corrosion on the fire performance of RC beams. The corroded RC beams were prepared using an accelerated corrosion test, and the fire test was carried out according to the ISO 834 standard fire. Test results indicated that corrosion of the tensile steel bars led to premature failure of the concrete beams. During the fire tests, with the increase of the steels’ degree of corrosion, the midspan deflection of the RC beam rapidly develops, while the fire resistance obviously decreases. Because the thermal diffusion coefficient of air is higher than that of concrete, a corrosion induced crack increased the heating rate of the corroded steel bar inside the concrete, and the vertical cracks caused by the applied loading had a significant impact on the temperature field of the beam tensile zone. Notably, reinforcement corrosion may lead to brittle failure in a balanced-reinforced beam subjected to fire.