Flexural behaviour of corroded RC beams exposed to fire

Abstract

Reinforced concrete structures located in coastal areas face durability-related concerns such as reinforcing steel's corrosion due to aggressive and humid environments. An accidental fire in such a scenario can lead to a severe loss of mechanical properties and load-carrying capacity. This paper examines the load–deflection response of short-span RC beams on account of exposure to combinations of corrosion-induced damage and exposure to elevated temperatures. The idea pertinent to this study is to simulate a fire in an old or aged structure located in a humid environment. The study involved flexure testing on normal strength reinforced concrete beams reinforced with SD TMT (Super Ductile thermo-mechanically treated) bars. The RC beam specimens were exposed to impressed current to achieve desired corrosion levels in terms of mass loss of 4% & 8% and subsequently to elevated temperatures (400 °C and 600 °C) under a steady state. The beams were tested in flexure, and the load–deflection response was observed. The results indicate a notable reduction in load–deflection behavior due to the two non-linear phenomena' superimposition. It was concluded that the exposure to combinations mentioned above of corrosion-induced damage and elevated temperatures caused significant loss of load–deflection response of RC beams.