Long-term sulfate attack: Mechanisms and evolution of resistivity and strength in solidified mud

Understanding the impact of sulfate-rich environments on the durability of solidified mud is critical for advancing its application in challenging conditions. This study explores the correlation between resistivity and strength in s lurry-like mud (MS) stabilized by conventional cement solidification (CCSM) and the flocculation-solidification combined method (FSCM), with a particular focus on their long-term performance in sulfate-rich environments. The research examines the material at both the macro and micro scales. First, the impact of key parameters (such as salt concentration and erosion duration) on the resistivity of solidified mud is evaluated through resistivity testing. Next, unconfined compressive strength (UCS) tests are used to assess the long-term strength evolution of both materials under sulfate conditions, facilitating a correlation analysis with the resistivity data. Finally, microscopy techniques are used to characterize the microstructural evolution of both solidified mud types under sulfate attack. The results show that both CCSM- and FSCM-stabilized MS exhibit distinct three-stage degradation characteristics when exposed to sulfate attack. The inclusion of flocculants enhances the durability and stability of solidified mud under corrosive conditions. Unconfined compressive strength and resistivity show a strong linear correlation ( ρ-q u curve), highlighting the potential for using resistivity as a predictor for strength. However, this correlation is significantly affected by sulfate concentration. As a non-destructive and rapid method, resistivity testing can effectively predict material strength and infer internal degradation.