Preparation of rejuvenating agent and property evaluation of rejuvenated SBS modified asphalt binders

摘要

Currently, more and more waste SBS modified asphalt binders (SBSMA) were produced from asphalt pavement. To achieve concept of green development of asphalt pavement, thus, the objective of rejuvenation of waste SBSMA become very important. This paper investigates physical and chemical properties of rejuvenated SBSMA. The optimal content of rejuvenating agent was determined by conventional tests to rejuvenate aged SBSMA to its unaged level. The research about conventional tests indicated that rejuvenating agent can both improve the ductility at low temperature of aged SBSMA and elastic recovery of aged SBSMA. Physical properties and microstructures of unaged, aged, and rejuvenated SBSMA were then investigated, and by contrast, rejuvenating agent can improve workability of aged SBSMA due to the reduction of viscosity and improve its cracking resistance at low temperature. Moreover, the fourier transform infrared spectroscopy (FTIR) illustrated that there was no chemical reaction occur between rejuvenating agent and aged SBSMA. The original structure of SBS modifier can be partly rebuilt through adding the rejuvenating agent. In thermal analysis and GPC analysis, the large molecule size (LMS) content of aged SBSMA are decreased due to physical dilution and the thermal stability of aged SBSMA is increased when rejuvenating agent was added. From the analysis, it is found that the properties of aged SBSMA would be improved with the addition of rejuvenating agent. (C) 2019 Elsevier Ltd. All rights reserved.