EFFECT OF DAMAGE ON FIRE RATING OF RC-BEAMS

Abstract

The main purpose of this study is to investigate the effects of pre-damage on fire resistance of reinforced concrete structures under standard fire conditions. For this, a loaddisplacements curve analysis is carried out in simply supported condition. From this curve, we found out the load required for damage of beams in terms of deflection. After the damage steps, such beams are exposed to fire on three sides and fixed point load is applied on the top surface of beam up to ultimate failure. In one case of fire exposure test, four RC-beams are exposed with fire for one hours duration. In other case of fire test, a reinforced concrete beams were tested to obtain the effect of pre-damaged on fire resistance. An analytical works aere carried out to develop a proposed equation to determine the fire resistance of damage and undamaged beams. Results obtained from these fire test are compared with the results that of obtained from some simplified proposed equation and put forward some conclusions and recommendations concerning the fire design of reinforced concrete beams. The experimental programmes involve of casting and testing of beams of size (I 800mmx300mmx 150mm).