钢筋混凝土楼板隔火能力的耐火当量时间

The fire resistance equivalent time of fire insulating ability of RC floorslab

我国现行规范在规定钢筋混凝土楼板耐火极限时,并未考虑火灾荷载和通风条件。从隔热性方面研究了钢筋混凝土楼板的耐火极限,以室内火灾轰燃后的房间热平衡和热传导理论为基础,以钢筋混凝土楼板火灾中背火面的最高温度相等为原则,利用计算机数值分析方法计算出楼板的隔火当量时间,并用最小二乘法回归出当量时间关于火灾荷载密度和开口因子的计算公式,可使设计方法得到简化,为性能化防火设计提供参考。

The fire load and the ventilated condition namely latent fire environment were not considered when the reinforced concrete floorslab＇s duration of fire resistance is ordained in our country＇s current criterion. The duration of fire resistance of the reinforced concrete floorslab is researched from the aspect of the heat insulation. The fire insulate equivalent time is derived by numerical analysis on base of the theories of heat balance of compartment post-flashover and heat conduction and the principle that the maximal temperature of the back reinforced concrete floorslab in the compartment fire equals to that of standard fire, and an equivalent time formula about fire load density and ventilation factor is given by the least squares. Thus, the method of design is simplified, and will provide a certain reference to the future design based on fire resistance.