Experimental Research on Load-Bearing Capacity of Fire-Damaged Reinforced Concrete Continuous T-Beams

In order to research the effects of heating and cooling on the load-bearing capacity of fire-damaged reinforced concrete (RC) continuous beams, loading tests of three RC continuous T-beams were conducted. A parametric analysis for the load-bearing capacity of fire-damaged RC continuous beams were carried out with the finite element method. A simplified method for evaluating the ultimate load of RC continuous beams after fire was presented. The research results show that a fire-damaged RC continuous T-beam exhibits a low midspan yield load, ultimate load and stiffness compared with a control T-beam, and the decrease of stiffness is greater than that of the load-bearing capacity. Within heating time of 120 min, ratio of reinforcement has a significant effect on the load-bearing capacity of a fire-damaged RC continuous T-beams, while heating time and concrete strength have a finite influence. The simplified method is capable of predicting the ultimate load of fire-damaged continuous RC beams exactly.