为了研究防火涂料破损对钢柱抗火性能的影响,采用火灾试验炉进行两个端部防火涂料破损的钢柱抗火性能试验,破损长度分别为钢柱长度的7%和14%,钢柱设计荷载比为0.55,试验得到钢柱的破坏现象和临界温度。试验表明钢柱在火灾中的破坏位置位于防火涂料破损段;防火涂料破损长度对钢柱抗火性能影响较大,破损段越短,临界温度越高;钢柱的破坏特征是防火涂料破损段钢柱屈曲或屈服。采用连续体模型和有限元方法,对试验构件和影响临界温度的参数进行分析,将分析结果和试验结果进行对比,分析发现荷载偏心对临界温度影响较大,端部约束刚度对临界温度影响较小。
In order to investigate the influence of damage of fire retardant coating (FRC) on the fire-resistance performance of steel columns, an experimental study on the fire-resistance performance of two steel columns were performed in furnace. The steel columns were protected by FRC and the length of damage of the two columns was 7% and 14% of the column length, respectively. The load ratio of the two columns was 0. 55 and their ends were connected by flush end plates. The experimental results indicate that the columns failed in the location of the FRC damage and the length of the FRC damage had a significant effect on the fire resistance performance of the steel columns. The shorter the damage length of the FRC was, the higher the critical temperature of the steel columns. The failure modes of the two columns were buckling or yielding at the FRC damaged region. The analytical results by a continuum model of the specimens were compared with the corresponding test results.