关键词: 钢管混凝土柱, 防火涂料, 局部脱落, 温度场, 有限元

Abstract: Local damage of sprayed fire protection of concrete-filled steel tubular (CFST) columns could happen in engineering practices, which may affect the temperature field and further the fire resistance of the column. To obtain the temperature distribution of CFST columns with local damage of fire protection and provide recommendations for the fire design of the locally-damaged columns, a finite element model was developed using ABAQUS. The influences of coefficient of the cross-section shape, column length, location and length of the damaged fire protection, thickness and thermal properties of the fire protection on the temperature distribution were analyzed. The development of temperature in a circular section is similar to that in a square section and the former is slightly higher than the latter. Based on geometric symmetries, the conditions in which the fire protection is damaged at two ends or mid-height of the column could be equivalent to the condition of the one-end damage. The local damage of fire protection only influences the temperature of the CFST column within a limited area. The length of the affected area increases with the increases of the heating time, the damage length, the thickness of the protection and the decreases of the thermal conductivity of the protection and the coefficient of the cross-section shape.

Key words: concrete-filled steel tubular (CFST) columns, fire protection, local damage, temperature distribution, finite element