Moisture damage in pavements, particularly in Hot Mix Asphalt (HMA), occurs due to breakdown of adhesion and cohesion, which results in reduced strength and causes pavement distress. Stripping, a prevalent surface defect in flexible pavements, contributes to moisture damage. The primary approach to mitigating this damage involves incorporating additives or modifiers into asphalt binder or aggregate. This study investigates the performance assessment of HMA mixtures by substituting Ground Granulated Blast-furnace Slag (GGBFS) a filler material, focusing on volumetric and mechanical properties under diverse compaction (35, 50 and 75 blows) and moisture conditions (Dry and wet). Field moisture conditions are simulated using a standard water bath with varied adhesion times. Results indicate that wet-conditioned samples with low compaction levels exhibit inferior characteristics compared to dry-conditioned samples with higher compaction levels. Furthermore, the substitution of GGBFS as the filler material reduces the moisture susceptibility of the HMA mix.