钢筋混凝土轴心受压柱的抗火设计方法研究

该文以四面受火钢筋混凝土轴心受压柱为研究对象,在利用自编钢筋混凝土温度场有限元分析程序进行大量数值分析计算的基础上,通过引入材料平均强度折减系数的概念,建立了截面材料性能随受火时间变化的规律,从而提出了一种类似常温下钢筋混凝土轴心受压柱设计计算的抗火设计新方法,并编制了相应的分析程序。这种设计方法不直接依赖于具体的温度场分析,仅取决于受火时间的长短,为设计人员的抗火设计工作提供了很大便利。最后,利用大量试验数据与该文提出的方法进行了对比研究。结果表明:该文提出的钢筋混凝土轴心受压柱抗火设计方法是安全而有效的。

FIRE RESISTANCE DESIGN METHOD OF AXIALLY LOADED REINFORCED CONCRETE COLUMNS

The main objects of this paper are axially loaded reinforced concrete columns under the condition of four-face heating. Based on a lot of numerical analysis using finite element program for the reinforced concrete temperature field developed by the authors, a concept of mean strength reduction factor of material is introduced, the time-dependent material properties are established, and a simple design method which is similar to the design method used for reinforced concrete columns at ambient temperature is proposed. This design method is not directly dependent on the temperature field of the reinforced concrete cross-sections, and is only determined by the fire exposure time, so it is very convenient for design engineers. At last, the comparison between the experimental data and the theoretical results shows that the proposed fire resistance design method of axially loaded reinforced concrete columns is effective and safe.