高温后混凝土和钢筋强度的统计分析

通过对我国有关高温后普通混凝土抗压强度、热轧钢筋屈服强度和预应力钢筋极限强度的大量试验数据进行统计分析，发现在绝大多数情况下他们与各自常温强度之比（注：本文称该类比值为相对残余强度）均符合正态分布。给出了不同温度作用后三类建筑材料相对残余强度的均值和均方差，分别建立了高温后三类建材的相对残余强度均值和具有95%保证率的分位值随温度的定量变化关系。作为火灾后钢筋混凝土结构可靠性评估的基础，积极开展高温后各类建筑材料的力学性能统计分析是十分必要的。

Statistical Analysis of Strengths of Concrete and Steel Bar After High-Temperature Treatment

Based on the statistical analysis of a lot of test data on compressive strength of normal-strength concrete, yield strength of mild steel bar, and ultimate strength of prestressed reinforcement after high temperature, it is found that the ratio of the strength after high temperature to that at room temperature（i.e., relative residual strength in this paper）is consistent with the Normal distribution. The mean values and variances of the relative residual strengths of the above materials after different high temperatures are given, and the relationships between the mean value/the value with 95% excess probability and the temperature are proposed, respectively. As a basis of the reliability assessment of reinforced concrete structures after fire, it is important to study the statistical mechanical properties of the above materials after high temperature.