Study On Preparation Technology Of High Modulus Asphalt

The asphalt pavement rutting damage has been a widespread attention in domestic and international engineering applications. Due to the excellent characteristics of anti-rutting in high temperature performance and economical efficiency, high modulus asphalt has extensive application prospects. In this paper, high modulus asphalt was prepared by using different raw materials and production processes. At the same time, high modulus asphalt was studied comprehensively through the performance evaluation and SHPR experimental research.Firstly, the optimal process conditions of the preparation of waste polyethylene(PE) modified asphalt was obtained by orthogonal design, then different raw materials and production processes were selected for preparing high modulus asphalt. Modification process tests indicated that the penetration at 25℃ and ductility of high modulus asphalt decreased with the increase of modifier content, while high temperature performance and anti-aging performance gradually improved. From blending process tests, with the increase of soft component content, high temperature performance and anti-aging performance of high modulus asphalt reduced, while the workability and ductility increased gradually.The selection of target samples and performance comparison were carried out through the high modulus asphalt which had been prepared. Comparing different raw materials and different production processes of high modulus asphalt, it was obvious that the high temperature properties and anti-aging performance were improved by modification process. In terms of ductility, the blending process with oxidized asphalt was better than the others, while the blending process with DOA had a slight advantage in the field of workability. In terms of temperature stability, the temperature sensitivity of high modulus asphalt which were prepared by blending process with Huabei DOA and anti-rutting agent modification process were superior to the other three processes.The SHRP experimental research of high modulus asphalt showed that the complex modulus(G*) of asphalt was improved greatly and the high temperature performance of asphalt was improved obviously after adding modifier. From the SHRP tests, the high temperature performance of high modulus asphalt ranked in this order: waste PE modification > anti-rutting agent modification > Changqing DOA and oxidized asphalt > Huabei DOA. It was consistent with the result that using softening point to evaluate the high temperature performance of high modulus asphalt prepared by different processes.The high temperature grade of high modulus asphalt prepared by different production processes were improved compared with matrix asphalt, while the low temperature grade of high modulus asphalt was decreased only prepared by the blending process with DOA. In terms of anti-fatigue performance, high modulus asphalt prepared by different processes had been improved.Through the correlation of high temperature index of asphalt, softening point and viscosity at 60℃ could replace appropriately the complex modulus(G*) to evaluate high temperature performance of asphalt. Finally, this paper also studied and put forward the technical index requirements of high modulus asphalt.