Molecular dynamics study on the cohesive fracture properties of functionalized styrene-butadiene rubber modified asphalt

The cohesive fracture properties are significant for the fracture and deformation resistance of porous asphalt pavement. In this study, the cohesive fracture properties of the functionalized styrene-butadiene rubber modified asphalt composites are investigated by molecular dynamics simulations, and the influence of various types of functionalized styrene-butadiene rubber and temperature effects are examined through the tensile test. It is found that the cohesive resistance of asphalt composites is reinforced by functionalized styrene-butadiene rubber but damaged by rising temperatures. The functionalized styrene-butadiene rubber chains can impede the void generation at the initial stage, which can restrict the further separation of the asphalt matrix through the bridging effect. The H-bond interactions between the functional groups and polar components of asphalt play a crucial role in the non-bond interactions of functionalized styrene-butadiene rubber and asphalt, which can impede the localized movement and deformation of asphalt. The in-depth understanding of reinforcing mechanisms in the cohesive failure will help the design of functionalized styrene-butadiene rubber modified asphalt composites adopted in the next generation of porous asphalt pavement. © 2024 Elsevier B.V.