The fracture failure of granite after varied durations of thermal treatment: an experimental study

Energy-extraction from nuclear materials produces high-level radioactive waste (HLW). In geological nuclear waste storage repositories, the decay of radioactive elements generates heat, exposing the reservoir rocks to high-temperature conditions for long periods. To explore the effects of these conditions, this study examines the ability of granite to resist fracturing after thermal treatment for 10 hours, 10 days, 30 days, and 60 days. The results show that: The fracture toughness of the granite remained basically unchanged with up to 10 days of thermal treatment. After thermal treatment for 60 days, the mode-I, mode-II and mixed-mode (I+II) fracture toughness decreased by 15.39%, 18.07% and 15.18%, respectively, compared with samples heated for 10 hours. The change trends of the ability of granite to resist tensile, shear and mixed (tensile + shear) failure with increased thermal treatment duration were basically consistent. Moreover, there was little change in its brittle fracturing ...

核材料能源提取过程会产生高放废物（high-level radioactive waste，HLW）。在核废料地质储存库中，放射性元素衰变产生的热量会使储层岩石长期处于高温环境。为探究此类环境的影响，本研究针对经10小时、10天、30天及60天热处理后的花岗岩抗断裂性能展开了试验分析。试验结果表明：当热处理时长不超过10天时，花岗岩的断裂韧度基本保持稳定；与热处理10小时的试样相比，经60天热处理后，花岗岩的I型、II型及混合型（I+II）断裂韧度分别下降15.39%、18.07%及15.18%。随着热处理时长增加，花岗岩抗拉伸、抗剪切及抗拉剪混合失效的能力变化趋势基本一致。此外，其脆性断裂特性几乎未发生明显变化……