A study on the bonding performance of PU/AC interface

Abstract

The tensile debonding process of a polyurethane (PU)-asphalt concrete (AC) adhesion system under different temperature fields was simulated in this paper using LAMMPS molecular simulation software, and the interfacial energy, radial distribution function, mean square displacement, number density curve, and force-displacement curve of the system were calculated. When the temperature was below 280 K, adsorption occurred between PU and asphalt, asphalt and silica, and PU and silica, but the interfacial energy between PU and silica and PU and asphalt was larger than that between asphalt and silica. A large number of PU molecules exist in the range of 5Å from the silica and the MSD curve of PU has a low value as a function. During the tensile process, the silica crystals and asphalt in PU-AC systems travel with the PU, and the final fracture location emerges inside the asphalt molecule rather than at the PU/AC contact. When the temperature rises over 280 degrees Celsius, only asphalt and silica remain after the stretching action, and adsorption between asphalt and PU occurs, but adsorption between PU and silica vanishes. Distance from the silica is 5Å range only a small amount of PU molecules, stretching model, PU molecules gradually detached from the asphalt and silica, the final damage section close to the PU/AC interface. The mechanical characteristics of PU/AC bonded specimens at different temperatures were evaluated in this work to validate the correctness of molecular simulation, and the test findings were in good agreement with the conclusions of molecular simulation. The results of this paper provide molecular-scale insights into the debonding mechanism of PU/AC interfaces.