Research On Fire Performance Of Restrained Steel Reinforced Concrete(SRC) Columns With +-shaped Cross Section

The steel reinforced concrete(SRC) special-shaped column has the advantages of high load bearing capacity, excellent earthquake resistance qualities, flexible building function, it has got more and more attention in modern buildings.At present,the study of steel reinforced concrete columns mainly focus on seismic performance and earthquake resistance behavior at room temperature,and the study of its fire behavior is little.The area of exposed in the fire of the steel reinforced concrete special-shaped columns with the +-shaped cross section is larger than the common columns,so the fire stability of these columns is lower than the common columns.Therefore this paper carried out the research of fire resistance of steel reinforced concrete columns with ten shaped section,The calculation method is established to figure the columns, and It has theoretical significance and engineering application value.The main research contents are as following:(1) By analyzing and comparing the domestic and foreign literature, the thermal parameters and constitutive relation model of concrete and steel are selected to calculate model.(2) Established restrained steel reinforced concrete columns with +-shaped cross sections subjected to all-around-face heating by using the software of ABAQUS, and The rationality of the model is verified by the fire resistance test data of ten steel reinforced concrete special-shaped column shaped section, PEC columns and steel reinforced concrete columns(3) The validated model was used to analyze the axial force and displacement of the columns on related factors, such as sectional dimension,load ratio, eccentric ratio,axial restraint stiffness ratio,rotational restraint stiffness ratio, slenderness ratio.(4) Influence of following parameters, such as sectional dimension,load ratio, eccentric ratio,axial restraint stiffness ratio,rotational restraint stiffness ratio, slenderness ratio on fire resistance of the columns under fire condition was analyzed,thus get the influenced law of these factors.(5) Through analyzing and sorting out the above parameters influence on the fire resistance limit of date.fitting the fire proof limit applicable formula for the restrained steel reinforced concrete columns with +-shaped cross sections under certain conditions. And through the comparison and analysis, to verify the accuracy of the calculation formula.