方钢管混凝土柱耐火极限影响因素分析

研究了方形截面钢管混凝土柱的耐火性能 ,分析了材料强度、构件截面含钢率、截面尺寸、构件长细比及荷载偏心距、保护层厚度等参数对构件耐火极限的影响。结果表明 ,材料强度、构件截面含钢率、荷载偏心距对方形截面钢管混凝土柱耐火极限的影响不大 ;截面尺寸、构件长细比对方形截面钢管混凝土柱耐火极限的影响较大 ,且截面尺寸越大 ,构件耐火极限越长 ,长细比越大 ,构件耐火极限越短。并指出可以通过涂以一定厚度的防火涂料保证方形截面钢管混凝土柱达到要求的耐火极限

PARAMETERS ANALYSIS OF THE FIRE RESISTANCE OF CONCRETE FILLED STEEL TUBULAR COLUMN WITH SQUARE SECTIONS

The influences of the significant parameters,such as strength of materials,steel ratio,column section dimensions,slenderness,load eccentricity,thickness of fire protection layer of a concrete filled steel tubular column with square section on its fire resistance are studied.From the results,it is indicated that the influences of strength of materials,steel ratio,load eccentricity are not significant. But the influences of column section dimensions,slenderness are greater.The fire resistance increases with increasing the column section dimensions,and decreases with increasing the slenderness.And from the results,it is shown that the fire resistance of the concrete filled square steel tubes can reach the required point by simply adding fire protection with certain depth to the column's surface.