| dc.description.abstract | Due to the routine road maintenance and rehabilitation in Taiwan, milling process produces big pile of Recycled Asphalt Pavement (RAP). This study then aims to perform laboratory investigation to discover the rejuvenating effect of Recycling Agent (RA) on the performance of aged asphalt binder and asphalt concrete in order to increase RAP usage. This study blends 40% of 100,000 poise Recycled Asphalt Binder (RAB) with AC 20 as virgin binder and four types of RA comprising RA 1-1, RA 1-2, RA 25-2, and RA 75-2. The first phase which focus on asphalt binder employed viscosity blending chart from Asphalt Institute MS-2 (AI MS-2) which Taiwan commonly uses to find optimum necessary RA in the blends. The results of first phase indicate that RA are able to rejuvenate RAB. However, the results of Multiple Stress Creep Recovery (MSCR) test indicate that this method mislead the addition of RA in the blend and results in softer RAB Blends which is suscpetible to rutting. Most of the RAB blends are above the maximum allowable Jnr for standard traffic, 4.5 kPa-1. Then, the second experimental which focus on asphalt concrete was carried out with assumption that it will be more compatible with their characteristic and solve the problem in rutting. It employed penetration grade to find optimum necessary RA in the blends. The results shows that the decreasing of RA 1-1, RA 1-2, RA 25-2, and RA 75-2 needed in the blends about 39.08%, 13.99%, 5.71%, and 6.43% can be observed respectively. Taiwan sets the standard that when the 12.5 mm rut depth occured, the maximum number of passes through this rut of depth must be higher than 12,000 passes. The result of Hamburg Wheel Tracking test shows that RAB rejuvenated by RA 1-1 which based on penetration grade shows good rutting performance, unlike the results of RA 1-2 MIX. It is due to characteristic of RA 1-2 which is susceptible to temperature and frequency change based on its penetration index and rheological test respectively. Moreover, chemical components of RA 1-2 shows high in resin and aromatic content which produce asphalt binder with more viscous structure. Thus, for the case of rejuvenating severely aged and quite high content of RAB in the blend, relying on only viscosity test and AI MS-2 is not adequate. Determining RA based on penetration grade, then also considering the chemical component of RA and its rheological test is more compatible. | en_US |