EXPERIMENTAL STUDY AND THEORETIC ANALYSIS ON FIRE RESISTANCE OF ANGLE STEEL STRENGTHENED REINFORCED CONCRETE COLUMNS
Xiao-Yong Mao*, Li-Ren Zhou and Zhen Zhang
Department of Civil Engineering, Suzhou University of Science and Technology, Suzhou, China
Experiments on fire resistance of four angle steel strengthened reinforced concrete (ASSRC) columns under ISO834 standard fire were carried out. Failure mode, deflection and fire resistance of the columns were presented. Thermo-structure coupling analysis model was built up considering the spalling of the mortar fire insulation, which was validated by the test data. Then the validated model was used to analyze the effect of load level, eccentricity ratio, fire protection thickness and increasing coefficient of carrying capacity on fire behavior of ASSRC column. The results showed that, epoxy resin reached its failure temperature and lost mechanical strength with the spalling of mortar insulation in a short time, leading to a poor fire behavior of ASSRC columns. With the increasing of load level, eccentricity ratio and coefficient of carrying capacity, fire resistance of ASSRC columns decreases, in which, the load level has a notable influence. Thicker fire protection of mortar can retard the heat transmission process, corresponding to a better fire resistance.
Angle Steel Strengthening; Fire Resistance; RC Columns; Thermo-Structure Coupling Analysis