Effect of humidity on fracture toughness and slow crack growthin sandstone

摘要

Subcritical crack growth (SCG) is one of the main causes of time-dependent fracturingin rock. Therefore, it is important to study SCG in rock. Additionally. the information of the fracturetoughness is also essential to know the fracturing in rock. In this study, the fracture toughness and SCG insandstone were investigated with Double Torsion method. Especially, the effect of the relative humidity wasinvestigated. It was shown that the fracture toughness decreased with increasing the humidity. For the meas-urement of SCG, it was shown that the stress intensity factor at a constant crack velocity also decreasedwith increasing the humidity. When the amount of clays was higher, the decrease of the fracture toughnessand the stress intensity factor for SCG with increasing the humidity were more significant. It is concludedthat the fracture toughness and SCG in sandstone are affected by the humidity and the amount of clays.