Investigation Of Warm-Mix Asphalt (Wma) With Chemical Additives For Moisture Susceptibility

To date, moisture induced damage is the most common pavement damage observed in warm-mix asphalt (WMA) pavement. This study evaluated moisture damage resistance of WMA with chemical additives through laboratory experimentation and repeated load- deformation analysis. To facilitate the study, two chemical WMA mixtures (Evotherm and Cecabase) and one control hot-mix asphalt (HMA) have been employed in this study. In addition, another Cecabase WMA containing polymer modified binder (PMB) has been employed to assess the polymer effect on chemical WMA. Laboratory evaluation have been conducted through Hamburg wheel tracking test (HWTT) results analysis. A new HWTT analysis encompassing viscoplastic and stripping induced strain have been successfully employed for better moisture damage evaluation. Two recently proposed moisture damage evaluation parameters, stripping number and stripping life, have been estimated. In addition, tensile strength ratio (TSR) test have been conducted for validating newly HWTT analysis results. Results and analysis revealed that permanent strain-based HWTT analysis is better predictive in moisture damage evaluation. The study found that chemical additives with non-polymerized binder showed equivalent moisture damage resistance as HMA. However, PMB utilization in chemical WMA resulted in improved moisture damage resistance.