In order to study the influence of asphalt from different
origins
on the compatibility of rubber powder and asphalt, the four most representative
90# asphalts from different origins were selected for the four-component
test, namely, Karamay, Shell, Esso, and HuanxiLing, which have differences
in their microstructure and molecular structure. First, Materials
Studio software was used to build the asphalt molecular model based
on the four-component test data, and styrene butadiene rubber and
natural rubber were used as representative molecules of rubber powder
to build the molecular model. The solubility parameters, molecular
potential energy, and radial distribution function were obtained by
molecular dynamics simulation of rubber powder and four asphalt molecules.
The gray correlation degree analysis of the four components of asphalt
is carried out with the gray correlation method. The results show
that the solubility parameter difference between Esso asphalt and
the rubber molecule is the smallest, and the potential energy between
them is the largest; that is, the compatibility between Esso asphalt
and rubber powder is the best, followed by Shell, Huanxiling, and
Karamay. The analysis of the radial distribution function between
two molecules also further confirmed the compatibility of the four
modified asphalt. The gray correlation degree between the four components
of asphalt and the solubility and molecular potential energy index
is as follows: saturates > aromatics > resin > asphaltene.
It is concluded
that the influence of light components on the compatibility of asphalt
is greater than that of heavy components. Therefore, in future industrial
production, the rubber powder-modified asphalt made of more light
components has better performance and storage stability.