Effect of Varied Durations of Thermal Treatment on the Tensile Strength of Red Sandstone

Excerpt

The strength of rocks differs with changes in temperature, pressure, time and fluid interactions, and the presence of joints and the stress history of the rock affect the strength. The cumulative presence of these factors in the underground environment alters the behavior of the rock. Since precise replication of these factors in laboratory-scale models is difficult, it is difficult to observe the change in the strength of rocks. However, it is imperative to study the effect of these properties on the strength behavior of rocks. Rocks have very low tensile strength compared to compressive or shear strength, making it easier for rocks to fail under tensile loading. The success in processes, such as underground coal gasification (UCG), enhanced oil recovery (EOR), underground nuclear waste disposal and geothermal energy, depends principally on the long-term stability of the host rock. In these processes, rocks are subjected to loading and heating. It is therefore vital to study the effect of temperature on tensile strength for designing structures within rock. …