高温后花岗岩巴西劈裂抗拉实验及超声特性研究

采用非金属超声检测分析仪和液压伺服试验系统装置，研究不同温度（25 ℃～1 000 ℃)作用后花岗岩的超声特性，分析不同温度条件下花岗岩的劈裂抗拉强度。结果表明，（1）高温后花岗岩的纵波波速、超声波形以及劈裂抗拉强度都与温度的变化密切相关；（2）随着温度的增高，花岗岩试样的纵波波速和劈裂抗拉强度逐渐减小，经历1 000 ℃高温后，纵波波速下降90%，劈裂抗拉强度下降65%，并且，纵波波速和抗拉强度间存在一定的相关性；（3）超声波波形随温度升高由整齐变混乱，由密集变稀疏，尤其在800 ℃波形变化最明显；（4）花岗岩试样的热损伤不断增加，经历1 000 ℃热损伤后，试样的脆性增加，变得轻脆易碎。

Research on ultrasonic characteristics and Brazilian splitting-tensile test of granite under post-high temperature

Ultrasonic characteristics and splitting-tensile strength of granite after exposure at temperature ranging from 25 ℃ to 1 000 ℃ are studied using hydraulic servo system and ultrasonic detector SRM-5N.The results show that(1) the longitudinal wave velocity,waveform and splitting-tensile strength of the granite are closely related to temperature;(2) the longitudinal wave velocity and splitting-tensile strength of granite gradually decrease with the temperature increasing,when the granite is exposed at 1 000 ℃,the longitudinal wave velocity and splitting-tensile strength decrease by 90% and 65%,and the splitting-tensile strength is bound up with the longitudinal wave velocity;(3) with the temperature increasing,the waveform of granite turns from regular to disordered,from concentrated to scattered,especially at 800 ℃;(4) the thermal damage enlarges and the specimens become fragile after exposure at 1 000 ℃.