材料期刊网

摘 要：为了得到高温后冷轧带肋钢筋的材料特性，本文对该钢筋（CRB550）在高温后的力学性能进行了试验研究。通过高温后的加载拉伸试验，得到了不同温度下冷轧带肋钢筋的屈服强度、极限强度、延伸率、面缩率和应力应变曲线，并测定高温后冷轧带肋钢筋的弹性模量。试验表明：冷轧带肋钢筋在400℃以内极限强度有小幅回升。随后随着经历温度的升高极限强度逐渐下降。并且该钢筋逐渐有硬钢特性变为软钢特性。同时考虑不同的灭火条件对钢筋的力学性能影响。通过对试验结果的分析。拟合得到冷轧带肋钢筋高温后的力学性能随经历温度变化的计算公式，这些公式可用于结构抗火计算或火灾后结构的加固分析与设计。

Abstract: experiments are carried out to determine the mechanical properties after high-temperature, such as yield strength, tensile strength, elongation, Poisson ratio and stress-strain relationship, of the cold—rolled deformed bar（CRB550）. And determine the initial Young’s modulus, also the thermal expansion coefficient of the cold—rolled deformed bar. Test results indicate that the ultimate Strength of the cold—rolled deformed bar before 400℃ is increasing than the ultimate Strength at natural temperature, and the ultimate Strength of the cold—rolled deformed bar is decreased after 400℃ .And considering the condition of the bar becoming cooling. In conclusion the functions of coefficients for mechanical properties of cold—rolled deformed bar under variable temperatures are developed by using a regression analysis and strength building of undergone fire.