Stress Performances Of Reinforced Concrete Beam By Simple Reinforced In The Fire And After The Fire And Repaired By Gluing The Steel Plates

Once the building has the fire, not only causes the huge damage to the people and the goods, but also produces the latent damages of the construction structure and its components. For instance the reinforced concrete beam is an important component withstanding vertical loads. If the beams'mechanical properties had the immense changes under the function of the fire in a short time , even the phenomenon of caving would happen along with the fire continuing to develop, the threatens are serious to the securities of the people's life and properties. In order to prevent this kind of disaster to occur, it is necessery to launch the researches of the concrete beams'mechanical properties in the fire and after the fire. As in the structure both the sides of the beam have received the constraints, then redistribution of internal force will take place when it is in force , so there would be an important impact on the ultimate bearing capacity of beams. In order to eliminate these effects, simply supported beams in clear force are used in this paper,which of the effects would be more intuitive.As the reinforced concrete beams by simple-supported are the material no-linear,and when the fire occurs, it is mainly undergone the coupling function,which is composed of the temperature stress produced by the fire and the loads that are transmited by the floors, the entire process is so complex.In order to show this effects clearly, we will take three identical beams to study in the different fire conditions. Focused on studing the changes of the beams'mechanical properties and the deflection in the different fire conditions with the same load case,and the damage of the beams'cross section produced by high-temperature.The remaining number of the residual capacity of the simply supported beams which experienced the high-temperature is essential, related to the problem whether to reinforce or not how to reinforce. how to calculate the remains of the bearing capacity of the beams by simple- supported after the fire and whether the results of simplified calculation can be used in engineering practice, is also the focus of this paper. In addition, the simplified calculation of the bearing capacity of the beams by reinforced after the fire was also discussed, and the feasibility of this method is reflected by.the way of comparing with the actual results of ultimate bearing capacity.This paper simulated a real fire environment and hoped could provide reference for the reinforcement by researching the changes of the mechanical properties of the full size of the simply supported beams in the fire and after the fire, residual capacity after the fire and the capacity of steel reinforcement. In this study, a simplified calculation method is only for a single component, does not apply to the whole building in the fire conditions. In addition, compareing with the predecessors'papers, software simulation is mainly used in them,the number of the full scale fire tests is few, however the significance of the test is precisely in this.