Acid Resistance of Alkali-Activated Natural Pozzolan and Limestone Powder Mortar

The development of sustainable, environmentally friendly alkali-activated binder has emerged as an alternative to ordinary Portland cement. engineering and durability properties using various precursor combinations have been investigated; however, no study focused on the impact high-volume natural pozzolan (NP) acid resistance NP limestone powder. Therefore, current assesses (volcanic ash) powder (LSP) mortar by immersion in 6% H2SO4 for 365 days. samples were prepared with different ratios alkaline activators (10 M NaOH(aq) Na2SO4) combined a 1:1 ratio cured at 75 °C. was LSP three combinations: NP:LSP = 40:60 (AAN40L60), 50:50 (AAN50L50), 60:40 (AAN60L40), representing low-volume, balanced, combinations. Water absorption, weight change, compressive strength examined. microstructural changes also investigated FTIR, XRD, SEM/EDS characterization tools. Visual examination showed insignificant deterioration sample excess (AAN60L40) after 1 year exposure, maximum residual strengths 20.8 MPa 6.68 AAN60L40 AAN40L60 mass gain (1.37%) loss (10.64%), respectively. high sulfuric attributed Ca/Si 10 within C-A-S-H N-A-S-H formed. low recorded result gypsum formation from attack calcium-dominated controlling factor corrosion NP/LSP ratio, whose below 0.6 caused significant debilitating effects.