STUDY OF INTERFACIAL ADHESION OF PAVEMENT SEALANTS BASED ON MOLECULAR DYNAMICS

To study the performance of bitumen mixture pavement sealants from their micro-mechanisms, the physical properties of base bitumen, SBS-modified bitumen and epoxy resin sealant as well as the adhesive properties of sealant-aggregate interfaces were studied using a molecular dynamics simulation. The adhesion of a sealant-pavement crack wall was studied using a contact angle test based on the surface energy theory. The results show that the epoxy resin sealant has excellent adhesion properties. Its physical properties and interfacial adhesion work are more significant than those of base bitumen and SBS-modified bitumen. An increase in the SBS can improve base bitumen’s mechanical properties and interfacial interaction. The interaction between three kinds of crack sealants and aggregate is identified as mainly the physical adsorption behavior. The van der Waals force plays a significant role in the adhesion behavior of bitumen crack sealant-aggregate interface. In contrast, the electrostatic force and van der Waals forces significantly affect the epoxy resin binder-aggregate interface. The adhesion work of 90# base bitumen, SBS-modified bitumen and epoxy resin binder for the asphalt pavement crack wall is (37.76, 44.86 and 77.63) mJ/m2, respectively.