火灾后隧道衬砌混凝土力学性能及微观结构实验研究

为研究火灾后隧道衬砌结构的损伤程度和性能特征,对火灾后隧道衬砌混凝土进行抗压强度试验和超声检测,分析不同受火时间(2,3,4 h)下,隧道衬砌混凝土剩余抗压强度和超声波声速变化的规律.结果表明:200～800℃范围内,不同受火时间下,受火温度和剩余抗压强度、超声波声速和剩余抗压强度都有较好的线性关系,且随受火时间增大,...

Experimental analysis of mechanical properties and microstructure of tunnel lining concrete after fire

In order to study the damage degree and performance characteristics of the tunnel lining structure after the fire, the compressive strength test and ultrasonic inspection of the tunnel lining concrete after the fire were carried out, and the residual resistance and the law of pressure intensity and speed of ultrasonic sound of the tunnel lining concrete under different fire time (2,3,4 h) was analyzed. The results show that: in the range of 200~800 ℃, under different fire time, the fire temperature and residual compressive strength, ultrasonic sound velocity and residual compressive strength have a good linear relationship, and with the increase of fire time, the ultrasonic sound velocity and compressive strength gradually decrease; Scanning electron microscopy-SEM shows that there is a good correlation between fire temperature, residual compressive strength and ultrasonic sound velocity. In addition, three calculation models of tunnel lining concrete compressive strength, fire temperature, and ultrasonic sound velocity in the range of 200~800 ℃ under different fire time have been established.