Evolution of thermal damage and permeability of Beishan granite
Evolution of thermal damage and permeability of Beishan granite
复制标题
北山花岗岩热损伤及渗透率演化
DOI：
10.1016/j.applthermaleng.2016.09.075
复制
发表时间：
2017-01-05
影响因子：
6.4
通讯作者：
Wang, Guibin
中科院分区：
文献类型：
--
作者：
Chen, Shiwan;Yang, Chunhe;Wang, Guibin
为了评价高温对北山花岗岩物理力学性质的影响，研究了北山花岗岩在不同升温速率下(100℃~800℃，1~15℃/min)的热损伤。采用声发射(AE)监测、声速和孔隙率测定、扫描电子显微镜(SEM)、渗透率测定三轴压缩试验等室内试验方法进行了研究。识别出两个温度阈值：300摄氏度和573摄氏度。加热后的花岗岩的物理力学性能随着温度的升高而减弱。特别是当温度超过573摄氏度时，减弱变得更加明显。花岗岩中的热诱发裂纹主要是100℃到573℃之间的沿晶裂纹，但一旦温度超过573℃，晶内裂纹就会由于石英的相变而开始发展。观测到了两种典型的花岗岩加热应力-渗透率曲线，并对其机理进行了分析。此外，还讨论了声发射击数与初始渗透率的关系。利用裂隙体积应变研究了压缩加载过程中渗透率的演化规律。(C)2016爱思唯尔有限公司。保留所有权利。
Thermal damage in Beishan granite subjected to high temperature treatment (from 100 degrees C to 800 degrees C at different heating rates, ranging from 1 to 15 degrees C/min) is studied in order to assess the thermal effect on physical and mechanical properties. Laboratory tests including acoustic emission (AE) monitoring, ultrasonic velocity and porosity measurements, scanning electron microscope (SEM), tri-axial compression tests with permeability measurement were applied in this study. Two temperature thresholds, 300 degrees C and 573 degrees C, are recognized. Physical and mechanical properties of heated granite weaken with the increase of temperature. Especially when the temperature exceeds 573 degrees C, the weakening becomes more pronounced. Thermally induced cracks in granite are mainly intergranular cracks from 100 degrees C to 573 degrees C. However, once the temperature exceeds 573 degrees C, intra-granular cracks begin to develop due to the phase transition of quartz. Two typical stress-permeability curves of heated granite are observed and their mechanism is analyzed. In addition, the relationship between the number AE hits and initial permeability is discussed. The volumetric strain of cracks is applied to study the permeability evolution during the compressive loading process. (C) 2016 Elsevier Ltd. All rights reserved.