花岗岩断裂韧度的高温效应

Effect of High Temperature on the Fracture Toughness of Granite

本文对作为核废料贮存母岩的花岗岩断裂韧度的高温效应进行了比较系统的研究。在室温至300℃范围内,获得了直接测定的花岗岩临界应力强度因子K_(1C)随温度变化的规律性试验结果。发现了一个门槛温度。高于这个门槛温度,花岗岩断裂韧度迅速下降。结合电镜观察,对该现象的机理进行了分析。本文指出,门槛温度应作为选择核废料贮存母岩的重要指标之一。

The effect of high temperature on the fracture toughness of the granite (Sui county, Hubei province) which is selected as the candidate of the parentrock for storing nuclear wastes was systematically studied. In the range of room temperature to 300℃, the test result of the variation of the critical stress intensity factors, Kic, of the granite with increasing temperature has been obtained. A threshold temperature, 200℃, was found, above which the fracture toughness of the granite decreases quickly. The fracture surfaces created after tests were reviewed by using an electronmicroscope. The mechanism of the variation of Kic for the granite with increasing temperature has been explained. It is suggested that the threshold temperature be used as one of the important criteria for selecting the granite as a parentrock for storing the nuclear wastes.