Effects of relative humidity and temperature on subcritical crack growth in igneous rock
Effects of relative humidity and temperature on subcritical crack growth in igneous rock
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DOI：
10.1016/j.ijrmms.2010.04.009
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发表时间：
2010-06
影响因子：
7.2
通讯作者：
Y. Nara;N. Hiroyoshi;T. Yoneda;K. Kaneko
中科院分区：
文献类型：
--
作者：
Y. Nara;N. Hiroyoshi;T. Yoneda;K. Kaneko
本文对熊本安山岩和大岛花岗岩的亚临界裂纹扩展进行了实验研究。应力强度因子和裂纹速度进行了测量，使用双扭转技术，所有的实验都在潮湿的空气中进行。我们的研究结果表明，在相同的相对湿度下进行的实验中，裂纹速度随着温度的升高而增加，与以前的研究一致。我们的研究结果还表明，在相同的温度下进行的实验中，裂纹速度显着增加相对湿度。相对湿度增加三到四倍导致裂纹速度增加一到四个数量级。这种增加大于经典应力腐蚀理论所预测的。提出小孔径裂纹尖端附近水蒸气的毛细凝结影响裂纹扩展速率。它的结论是，相对湿度需要加以控制，以避免随时间变化的削弱和延长岩体结构的寿命。
Effects of relative humidity and temperature on subcritical crack growth in igneous rock have been investigated experimentally on samples of Kumamoto andesite and Oshima granite. Stress intensity factors and crack velocities were measured using the double-torsion technique, and all experiments were conducted in moist air. Our results show that in experiments conducted under the same relative humidity, crack velocity increased with increasing temperature, in agreement with previous studies. Our results also show that, in experiments conducted at the same temperature, crack velocity increased dramatically with increasing relative humidity. A three- to fourfold increase in relative humidity resulted in an increase in crack velocity of between one and four orders of magnitude. Such an increase is larger than that predicted by classical stress corrosion theory. It is suggested that capillary condensation of water vapour close to crack tips of small aperture influences the rate of crack growth. It is concluded that relative humidity needs to be controlled to avoid time-dependent weakening and extend the lifetime of structures in a rock mass.