Research On The Adhesive Properties Between Asphalt And Aggregate

Moisture damage causes early damage of asphalt pavement and greatly reduces the asphalt pavement performance and service life.The adhesion properties between asphalt and aggregate and the state of asphalt wetting aggregate are the main factors that impact the resistance of asphalt mixture to moisture damage.This paper has done some research on the wetting and adhesive properties between the asphalt and aggregate under high and normal temperature respectively,based on the theory of surface free energy,and investigated the viscoelastic properties of the soaking asphalt mixture and asphalt mixture with no infiltration by using dynamic mechanical analysis(DMA)in a wide region of temperature.Through associating analysis,the reliability of the evaluation index of adhesion work was shown as following:Under the high temperature,the relationship between the adhesion work and temperature is in accordance with quadratic equation.In the quadratic equation,the maximum adhesion work and the corresponding temperature was obtained.And the maximum adhesion work between the base asphalt and aggregate is greater than the modified asphalt,which is closer to limestone and basalt on same asphalt.The corresponding temperature is higher when the asphalt has the higher viscosity and more softening point,which is closer to limestone and basalt on same asphalt.The maximum adhesion work under high temperature reflects the optimal wetting state of liquid asphalt on the surface of aggregate at the corresponding temperature.The temperature of the base asphalt is approximately equal to this mixing temperature,so it can be used as this mixing temperature.At the normal temperature,the surface energy is greater when the ductility and the penetration of the base asphalt are smaller,where softening point and the viscosity are higher;But the modified asphalt has the opposite characteristics.The limestone and the base asphalt have the best adhesion properties,and the basalt and the modified asphalt have the worst adhesive properties.When the grade of the base asphalt is lower with smaller penetration,the viscosity and softening point become higher and the adhesion properties between asphalt and aggregate is better.The adhesion work of limestone and asphalt is greater than the basalt,which is consistent with the resistance to moisture damage by using of dynamic mechanical analysis.So,it is able to illustrate that the size of the adhesion work between asphalt and aggregate can evaluate the adhesion properties and the ability of the resistance to moisture damage under normal temperature conditions.