Evolution of Mechanical Behaviors, Consolidation and Failure Mechanisms in Sandstone Materials Under Compressive Stress: The Role of Chemical Remediation Cycles

ABSTRACT The mechanical properties of rocks are severely degraded by water–rock fatigue interaction, posing risks to the safety and stability of rock engineering structures. This study aims to consolidate sandstone materials affected by water–rock fatigue interaction using chemically induced calcium carbonate precipitation. Some observational techniques, including X‐ray diffraction (XRD), nuclear magnetic resonance (NMR), and scanning electron microscopy (SEM), are employed to analyze the mineral composition and microstructural characteristics of chemically treated sandstone. Uniaxial compression tests integrated with acoustic emission (AE) monitoring are conducted on sandstone subjected to different chemical remediation (CR) cycles. The CR cycles significantly enhance the mechanical properties of sandstone. The original and water‐weakened microscopic pores and cracks within the sandstone are filled by chemically induced calcium carbonate precipitation. The dominant frequency (D‐F) and its corresponding amplitude of chemically treated sandstone are analyzed. The failure mechanism of chemically consolidated and water‐weakened sandstone materials is revealed by the distribution of low and high D‐F.