Method for evaluating lignin modified asphalt based on molecular dynamics simulation

Abstract

The invention discloses a lignin modified asphalt evaluation method based on molecular dynamics simulation, which comprises the following steps: constructing an asphalt system amorphous unit cell model, a lignin molecule amorphous unit cell model and a lignin modified asphalt amorphous unit cell model by using MS software; after molecular dynamics simulation is conducted on the model through a Forcite module, calculating cohesive energy density, then calculating the solubility parameter of the lignin modified asphaltl, and then calculating the mixing energy changes and Floriy-Huggins parameters of the lignin modified asphalt; analyzing the radial distribution function of each component in the asphalt system and the lignin modified asphalt system through the analysis function of the Forcitemodule. According to the method, the dynamic interaction between the matrix asphalt and the lignin is explained more essentially from the perspective of molecules, the change of the intermolecular structure of the modified asphalt is determined more visually and accurately, and the defects that a traditional experimental evaluation method is large in error and high in cost, and resources are wasted to a certain extent are overcome.

Description

technical field [0001] The invention belongs to the technical field of performance evaluation of modified asphalt, and in particular relates to an evaluation method of lignin-modified asphalt based on molecular dynamics simulation. Background technique [0002] Asphalt is an extremely complex mixture of hydrocarbons, which is an important component of asphalt pavement. Modified asphalt is prepared by adding modifiers such as waste tire rubber powder, SBS, etc., which improves the road performance of asphalt. Lignin, as a renewable natural polymer second only to cellulose in nature, has been widely used in plastics, adhesives and other fields in recent years, and has achieved good modification effects. [0003] In order to make full use of lignin and at the same time alleviate the phenomenon that the supply of petroleum is in short supply, some studies have added lignin as a modifier to asphalt to obtain lignin-modified asphalt. Studies have shown that lignin modification h...

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Problems solved by technology

[0017] In order to explain the dynamic interaction between base asphalt and lignin more essentially from the molecular point of view, to make accurate judgments on the changes in the molecular structure of modified asphalt more intuitively, and to overcome the traditional experimental evaluation methods with large errors and high costs, And the shortcoming that causes the waste of resources to a certain extent, the present invention provides a kind of evaluation method of lignin-modified asphalt based on molecular dynamics simulation

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