Experimental Research And Numerical Simulation On Fir Resistance Performance Of R.C. Columns With Stress Damages

Column was a kind of important stress members in reinforced concrete structures.Once column destroyed, it was possible to occur structural collapses. For theheterogeneity of using material and construction errors, there were no axial stressmembers in reinforced concrete structures. In general, Columns were eccentric stressmembers and exist different width cracks which were different stress damage index.Researching fire test of concrete eccentric compression column with stress damage hadvital significance.In order to obtain the distribution law of temperature field of columns，sectionunder different stress damages, establish the relationship between stress damage and fireresistance period and provide comparative date for numerical analysis, four concreteeccentric compression columns were designed to test. Based on purposes, this paper haddone the following research work:(1)Research status of fire test of concrete structures was analyzed from two aspectsbetween experimental study and numerical calculation.(2)Thermal performance and mechanical properties of reinforced bar and concretewere reviewed comprehensively and the constitutive relation and material parameterswere determined.(3)Four concrete eccentric compression columns under static test occurreddifferent maximum crack widths which were respectively0.05mm,0.1mm,0.15mm,0.2mm. The different crack widths represented different stress damages.(4)Fire tests of four concrete eccentric compression columns were conducted afterstatic test. Section temperature distribution, axial deformations and ultimatefire-resistance time were comparative analysis during four concrete eccentriccompression columns.(5)According to the actual fire tests heating curves, ANSYS was used to simulatetemperature field of section of eccentric compression columns. The nephogram oftemperature field distribution and the curve of temperature-time were obtained in thispaper. The feasibility and accuracy of ANSYS numerical simulation were also discussedhere.