THE EFFECT OF AXIAL RESTRAINT AND ROTATIONAL RESTRAINT ON THE FIRE RESISTANCE OF STEEL REINFORCED CONCRETE COLUMNS

摘要

Subjected to the restraints of the surrounding components, the actual boundary conditions of steel reinforced concrete frame columns are restrained on both ends in the field of steel reinforced concrete structure.The actual boundary conditions of frame columns could be divided into axial and rotational restraints according to the action of the restraints.A theoretical calculation model under the coupling effects between temperature and load was proposed, and the results of finite element analysis models were in good agreement with the experimental results.The fire performance of steel reinforced concrete columns was researched through detailed parametric analysis;different axial restraints and different rotational restraints were considered for column models.The results show:1) axial restraints have adverse influence on columns with low load eccentricity ratio in fire.2) axial restraints are beneficial to the columns with high load eccentricity ratio in fire.3) rotational restraints could improve the fire performance of columns.