Corrosion resistance and modification mechanism of modified anchoring grouting material in carbonaceous mudstone environment

• The modified anchoring grouting material (MAGM) significantly enhances mechanical properties in carbonaceous mudstone corrosive environments, with compressive strength, tensile strength, and shear stress peak increased by 85.9%, 44.4%, and 45.4% respectively after 28 days of corrosion. • The synergistic action of waterborne epoxy resin, curing agent, and nano-Al2O3 forms a protective network membrane structure that shields cement hydration products from corrosive ions. • Corrosion products adsorb onto the reticular membrane, filling pores and slowing ion erosion, thereby improving long-term durability. • Field application over 365 days shows MAGM maintains 55.3% higher peak shear stress than ordinary Portland cement grouting, ensuring slope stability.