Investigation of creep damage mechanical behaviors of red sandstone
considering temperature effect
Abstract
This work investigates the influence of temperature on the creep damage
behaviors of red sandstone. The samples treated at 25 ℃, 200 ℃, 400 ℃
and 600 ℃ are selected to carry out the uniaxial compression and creep
experiments. It is found that temperature has obvious influence on
uniaxial compressive strength, Young’s modulus and failure modes of red
sandstone. It can be also believed that the temperature can degrade the
mechanical behaviors of red sandstone. However, as the temperature
increases, the damage value does not always increase, the damage
variable has a negative value at 25 ~ 400 ℃. It can be
found that the higher the temperature, the larger the effect of loading
ratio on the ratio of creep strain to instantaneous strain, that is,
temperature reduces the ability of red sandstone to resist creep
deformation. Acoustic emission (AE) technology has been also used in the
loading process of uniaxial compression and creep tests. It is found
that the probability density of AE absolute energy of different samples
still satisfies the Gutenberg-Richter law well. In uniaxial compression
test, as the temperature increases, the absolute value of the critical
index increases exponentially. In the uniaxial creep test, as the
loading ratio increases, the absolute value of the critical index first
decreases and then increases. When the loading ratio is the same, as the
temperature increases, the absolute value of the critical index also
increases exponentially.