Analysis of diffusion behavior of waste edible oil and aged asphalt at room temperature

Abstract

Exploring the diffusion behavior of regenerant in aged asphalt system at room temperature is helpful to the study of cold regeneration of asphalt mixture.The effects of waste edible oil on the penetration, functional groups, complex modulus and phase angle of aged asphalt under different diffusion time were studied from macro and microscales by immersion method, Fourier transform infrared spectroscopy (FTIR) test and rotary rheometer test, and the test results were compared and analyzed. At the same time, based on the molecular dynamics theory, the molecular model of waste edible oil and aged asphalt was established, and the interface diffusion model was constructed. According to the diffusion coefficient, the diffusion behavior of the two in the system was revealed. The results show that waste edible oil can restore the basic technical performance of aged asphalt to ascertain extent at room temperature, supplement the light components missing due to aging, and restore its rheological properties. In addition, molecular dynamics simulation shows that the movement speed of waste edible oil molecules is faster than that of aged asphalt molecules, indicating that waste edible oil can soften aged asphalt in a short time. Therefore, it can be seen that the efficiency of wetting and softening aging asphalt of waste edible oil at room temperature is good.