Effects of Rejuvenator Dosage, Temperature, RAP Content and Rejuvenation Process on the Road Performance of Recycled Asphalt Mixture

Abstract

In this paper, the key technologies in the construction process of hot in-place recycling were investigated in order to improve the utilization rate of waste asphalt mixture; traditional lab tests including penetration, softening point and ductility tests, atomic force microscope test of recycled asphalt under different rejuvenator content, and the test of milling on grading at different temperatures were carried out. The influence of RAP content and rejuvenation processes on road performance were studied, and the low-temperature performance of mixture was analyzed by the energy analysis method, and the evaluation index was proposed. Test results indicated that the penetration and ductility increases, the softening point decrease with the rejuvenator content increasing, and the optimum rejuvenator content is 4%. The optimum mixing and compaction temperature will decrease by 2–6 °C on average for every 10% increase of RAP content by analyzing the mixture volume index. The results showed enhance rutting resistance of the mixture but lower moisture resistance and low-temperature crack resistance by adding the RAP content. The strain energy density of 10 KJ/m3 is proposed to evaluate the low-temperature performance of the mixture, and 30% RAP produces optimal mixture. The higher rutting resistance and moisture resistance can be obtained by using the construction process of RAP+ rejuvenator co-heating, and higher low-temperature crack resistance with RAP+ rejuvenator without heating.

Effect of Rapeseed Imidazoline Addition on the Properties of Lab-Aged 35/50 Pen Grade Bitumen

“…There are a number of available rejuvenating agents and rejuvenators of varying effectiveness [5][6][7][8][9][10]. They include conventional fats, such as plant or animal oils and mineral oils, including spent ones.…”

Compaction Characteristics of a Foam Asphalt Hot In-Place Recycling Asphalt Mixture

“…Due to the low mixing temperature and the presence of a significant amount of aged asphalt in the on-site hot recycled asphalt mixture, the efficiency of mixing is reduced [15]. This leads to insufficient compaction of the recycled road surface and poor-quality information, making it prone to early deterioration [16,17]. Warm-mix asphalt (WMA) technology can reduce the viscosity of asphalt binder without increasing the heating temperature [18], thereby improving the workability of the mixture and effectively enhancing the compaction quality of asphalt pavements [19][20][21].…”