Tang, Jin. Coarse grained molecular simulation of thermodynamic properties and compatibility of polymer and plastic modified asphalt. Retrieved from https://doi.org/doi:10.7282/t3-c9kg-v409
DescriptionAsphalt binder is produced from crude oil and used as common construction material for pavement surface of roadways, airports, and bridge decks. Asphalt can be modified using polymer to improve engineering properties and promote use of recycled material. This study aims to develop coarse grained models of asphalt binder and conduct molecular simulation to investigate thermodynamic properties and nanostructure of asphalt binder and understand the interaction and compatibility mechanism of polymer/plastic modified asphalt using molecular dynamics (MD) simulation.
The scope of work mainly includes: (1) building coarse gained dissipative particle dynamics (DPD) models of 12-components asphalt binder, and validating the model through experimental measurements at the nanoscale; (2) studying stacking behavior of asphaltene, diffusion properties of asphalt components, the relationship between aggregation of asphaltene and relative viscosity of asphalt binder, and colloidal structure of asphalt binders; (3) analyzing the compatibility between asphalt binder with different SARA (asphaltene, aromatic, resin and saturate) fractions and SBS (styrene–butadiene–styrene) polymers with different chain structures; (4) developing the generalized coarse grained molecular dynamic model for three-component asphalt binder and validating the model through density and viscosity; and (5) analyzing the effect of polyethylene (PE) structures on storage stability and self-healing potential of PE modified asphalt binder.
The results of coarse grained simulation were found reasonably consistent with the laboratory data and experimental findings. Coarse grained simulation is allowed to build a greater simulation system with less computing resource and fast computing speed as compared to traditional all-atom simulation. The thermodynamic properties and compatibility of polymer/plastic modified asphalt binders can be well represented from both dissipative particle dynamics and coarse grained MD, which can help material design of modified asphalt using an integrated computational and experimental approach. Besides, coarse grained simulation can be used to observe the micro-structures inner the greater-size asphalt binder, such as asphaltene aggregation behavior, the colloidal structure of asphalt binders, confirmation of polymer chains, and so on. This study suggests that coarse grained simulation is a helpful and useful technique to investigate the fundamental chemo-physical properties of polymer modified asphalt binders at the mesoscale.