Dynamic alteration damage to granite by SC-CO2: A proof of concept with an innovative apparatus design

Abstract Relevant studies on the dynamic alteration damage caused to rock mechanical characteristics by supercritical carbon dioxide (SC-CO2) have not been performed because a suitable experimental apparatus is not available. A dynamic alteration damage apparatus was thus developed to study long-term SC-CO2/water/granite interactions. Several design modifications were introduced to realize functions that cannot be implemented using existing apparatuses, mainly involving dynamic reactions and their accelerated tests. Dynamic alteration damage of uniaxial compressive strength (UCS), Young’s modulus and failure strain could be up to 14.95%, 19.38% and 20.71% severer than that of static alteration damage in 7-day (7-d) reaction time, verifying the non-ignorable impact of flowing working fluid. Accelerated testing errors of UCS in 5-d and 7-d dynamic alteration tests were 0.71% and 7.12%, respectively, so that the usability of accelerated test in studying long-term change trend of granite strength damaged by SC-CO2 was also proved.