Experimental investigation of moisture susceptibility of reclaimed asphalt binder using SFE approach

Abstract

Abstract Reclaimed Asphalt Pavement (RAP) refers to recycled pavement materials consisting of asphalt and aggregates. One of the use of RAP is as a material for new asphalt pavements. It can combine with new asphalt and aggregates to create a high-quality, durable road surface. This process reduces the amount of virgin material required in the production of new asphalt. It is investigated how RAP proportion and aggregate type affect moisture-induced deterioration in asphalt mixes. When the tensile strength of the asphalt binder deteriorates, or bonding failure appears at the asphalt binder-aggregate interface as a result of moisture, this is known as Moisture-induced damage. Investigating the risk of moisture-induced degradation in the asphalt binder-aggregate system by using the Surface Free Energy method (SFE). This method directly deals with the adhesion and debonding of asphalt binder and particles in the presence of moisture. The SFE parameters of VG-30 asphalt binder blended with various quantities of RAP binder (30%, 40%, and 50%) were measured using a Contact Angle measuring instrument. Work of adhesion, work of cohesion, wettability, and energy ratio were the SFE metrics studied. The results concluded that for VG-30 asphalt binders and aggregates, resistance to moisture-induced damage improved as the RAP level increased, particularly at higher RAP percentages. Furthermore, it was discovered that higher aggregate total SFE values corresponded to lower energy ratio values. As a result, a high aggregate total SFE component could make moisture-related damage to the mix more likely. According to the energy ratio statistics, using the binder with basalt provides more resistance to moisture damage than limestone and gravel.