Mechanical Properties and Energy Evolution of Red Sandstone Under the Influence of Acid Corrosion

This study aimed to investigate the effects of acid corrosion on mechanical properties and fractal characteristics of red sandstone. The mineral composition of red sandstone was analyzed using X-ray diffraction. The mechanical properties and acoustic emission (AE) signals of red sandstone specimens corroded by sulfuric acid solution with pH values of 1, 3, and 5 for 30 days were determined by uniaxial compression test and AE technique. The energy dissipation law and the fractal damage characteristics of red sandstone specimens after acid corrosion were analyzed based on the energy and fractal theories. The results indicated that the compressive strength and elastic modulus of red sandstone specimens corroded by acid solution decreased. In addition, the peak strain increased, the cumulative AE ringing count decreased, and the duration of high-level AE ringing shortened. These phenomena became more pronounced as the acidity of the solution increased. The peak values of the total energy and the elastic strain energy of the acid-solution-corroded red sandstone specimens decreased. The energy absorption capacity and energy storage limit of rock specimens also decreased. The fractal dimension and the degree of fragmentation decreased with the dissipated energy used for fragmentation. This research provides valuable insights into the prevention and control of sub-surface geotechnical hazards in acid rain-prone areas.