Study On Mechanical Properties Of Steel Reinforced Concrete Beams After Exposure To Fire

The SRC structure has a lot of advantages, such as high bearing capacity, large rigidity,excellent ductility, energy-dissipation ability and so on. Due to these advantages, the SRCstructure has become the new direction of RC development. At present, the low reliability of high-rise SRC building after frequent fire accidents leads to potential society risks, even endanger lifesafety. The mechanical behaviors of SRC beams after fire by tests and numerical simulations areresearched in this paper.In the fire test,7SRC beams with different shear span ratio are divided into two groups atvarious heating-up time. By loading the specimens after exposure to fire, the failure patterns, straindistribution along the height of specimen cross-section as well as the load-deflection curves andresidual bearing capacity of beams are obtained. The effect law of heating time, shear span ratio tothe bearing capacity and rigidity of specimens is analyzed.The mechanical properties of SRC beams at room temperature are analyzed by using thefinite element simulation software ANSYS in order to verify the feasibility of program calculation.Meanwhile, simulating the fire temperature fields in order to obtain the top temperature of eachnode in specimens and verify the calculation results by test examples. The residual capacity of steelreinforced concrete after fire is simulated by using of room temperature and temperature fieldcalculation methods as well as the determination of material strength degradations. Furthermore,the correctness of calculation results are verified through the test results.Five test parameters, section area, concrete strength, shear span ratio, steel ratio and heatingtime are determined to research the law of influence of residual resistance based on the correctnessmodel. The relationships of the SRC beams residual bearing capacity with heating time, steel ratio,shear span ratio and other factors have been determined through the numerical simulations, and thecalculation method of SRC beams bearing capacity after fire is summed up.