Shear properties of carbonaceous shale under acid corrosion

Aiming to investigate the deterioration mechanism of carbonaceous shale in acidic environment, direct shear tests were carried out on samples soaked in oxalic acid solution, and the macro-micro structure were scanned and analyzed. The results show that the plasticity of rock was enhanced significantly under acidic conditions. Carbonaceous shale can chemically react with oxalic acid, the fundamental mechanism of acid corrosion was the loss of mineral components and the irreversible damage of macro-micro structure. The increase of acidity and soaking time both aggravate the chemical damage, the shear properties gradually deteriorated, and eventually led to the serious deterioration of rock.