Analysis of performance parameters based on surface free energy to evaluate moisture susceptibility of asphalt mixtures modified with calcined marl dust

This study investigates the impact of calcined marl dust (CMD) on moisture susceptibility in asphalt mixtures with limestone and granite aggregates. The surface free energy (SFE) method and Hamburg wheel tracking test were used to assess this influence. Bitumen was mixed with various CMD percentages (0%, 10%, 25%, 40%) to analyze adhesion work, debonding work, and wettability. Results were utilized for energy ratios (ER1 and ER2) to gauge moisture susceptibility, while rut depth ratio (RDR) analysis was also conducted for these mixtures. The study found that higher aggregate total SFE correlated with decreased ER1 and ER2 values, showing strong correlation (R2 of 0.7974 for ER1 and 0.6572 for ER2) with RDR. At the optimal CMD content of 25%, the modified asphalt mix with limestone aggregate showed a 35% improvement in ER1 and a 21.6% enhancement in ER2, signifying improved moisture resistance.