Influence Of Components Proportion On Basic Road Properties And Glass Transition Temperature Of Asphalt

The influence of the microscopic composition of asphalt is one of the important internal causes,decided to road performance at low temperature by discussing the effect of components on the low temperature performance,from the aspects of asphalt materials for better clarifying the mechanism of low temperature cracking of asphalt pavement.At the moment,experts both at home and abroad are conducting considerable study on the low temperature performance of asphalt and its combination.However,because to the complexity of asphalt composition,testing the direct influence of asphalt composition on low temperature performance is impractical at the current technology level.As a result,this research explores the influence mechanism of asphalt components on the glass transition temperature using molecular dynamics modeling,beginning with the properties of asphalt molecular composition.To initiate,in order to investigate the influence law of asphalt component ratio of basic indicators,the matrix asphalt was modified by adding different concentrations of furfural extract oil to the harmonic of modified asphalt,measuring its basic performance indicators and component separation test,oil content analysis on the performance of asphalt and asphalt components,and component effect analysis on the asphalt performance indicators.The results reveal that furfural oil extraction can greatly improve asphalt penetration and elongation,while aldehyde oil extraction decreases softening point.The higher the asphaltene content and the lower the saturation level,the lower the asphalt penetration degree and the higher the softening point.Second,a molecular model of asphalt with four components and 12 molecules was constructed based on the proportion of components obtained from the separation test of asphalt components.According to the density change,the glass transition temperature of asphalt was determined.The error between simulated value and measured value of asphalt density is less than 5%.The molecular model of asphalt can accurately describe the microscopic composition of asphalt.The glass transition temperature of asphalt can be accurately obtained by molecular dynamics simulation.Finally,the effects of component ratio,wax content,different kinds of asphalt and related parameters on the glass transition temperature of asphalt were studied to clarify the influencing factors of glass transition temperature.The smaller the C/H ratio of asphalt,the more aromatic hydrocarbon and the less saturated hydrocarbon.The content of element S indicates that there are more sulfur-containing compounds in condensed aromatic hydrocarbons with relatively small molecular weight.The lower the glass transition temperature of asphalt,the better the low temperature performance.This thesis provides a strong theoretical support for the modification of asphalt and the improvement of low temperature performance of asphalt.