Abstract
In this study, a four-component test of aged asphalt, new asphalt, recycled asphalt on the surface of recycled old aggregate, and recycled asphalt on the surface of recycled new aggregate has been conducted based on the rod thin-layer chromatography (TLC)-hydrogen flame ion detection method to evaluate the colloidal stability index (Ic). Furthermore, the gelation index (GI) and recycling rate (P) of reclaimed asphalt pavement are defined. These parameters act as quantitative indicators of the recycling effect on the asphalt mixes and are used to characterize the degree of integration of the aged and new asphalt. The rationality of the evaluation indexes is verified by analyzing the effects of preheating, mixing temperature, and mixing time on the recycling effect. The results show that the proposed method based on rod TLC can effectively evaluate the thermal recycling efficiency of asphalt mixture, and it provides useful insights on the recycling effect of thermal recycling technology.