Fire resistance limit and its influence factors of axial restrained PEC columns subjected to standard fire

In order to investigate the influence of adjoining members on the fire resistance of PEC(Partially Encased Concrete) columns under the high temperature,the ABAQUS software of the finite element model was used to develop the model for numerical analysis of restrained PEC columns under the standard fire,and the model was verified by the test data.The verified model was then used to analyze the influence rules of the load ratio,axial restraint ratio,slenderness ration and eccentricity on the fire resistance limit of restrained PEC columns.The result shows that the limit tends to be low when the load ratio increases;the axial restraint ratio has little influence on the load ratio;the slenderness and load eccentricity have slight influence;under the same load ratio,the increase of slenderness leads to a slight decrease of the fire resistance of the PEC columns,and the increase of the load eccentricity leads to slight increase of the fire resistance of the columns.