Creep tests of red-bed sandstone after high temperature

Abstract

Temperature is an important factor affecting rock deformation and stability. The influence of temperature on the creep characteristics of red-bed sandstone is revealed through the creep test of red-bed sandstone after different high temperatures, and a creep damage model considering the temperature effect based on the Burgers model is established to analyze the influence rule of temperature on model parameters. The research results indicate that 510~550 °C is the nodal temperature range for the change in mechanical properties of red-bed sandstone. Below this temperature range, with the temperature increases, the peak strength of specimen increase, ductility increases, and the long-term strength decreases. Above this temperature range, with the temperature increases, the peak strength and peak strain of specimen decrease, and the long-term strength increases. The instantaneous strain increases linearly with the increasing temperature. Under the same stress conditions, with the temperature increases, the instantaneous strain of specimen, the steady-state creep rate and the time to enter the stable creep stage increase, the time to enter the accelerated creep stage decreases, and the acceleration creep curve becomes steeper.