Research On Hot Mix Regenerant Of Waste Pavement Asphalt

With the growth of roads’ service life, road performance decreases sharply and can not meet using requirements. However, a lot of waste asphalt mixtures will be produced in the rebuilding process, if handled improperly, it will not only pollute the environment, but also cause great waste of resources. Therefore, development of waste asphalt regeneration technology has become one key topic of the industry. In this paper, based on the aging mechanism of asphalt and regeneration mechanism of aged asphalt, two series of regenerants had been researched and developed for base asphalt and SBS modified asphalt. Simulating aging was used to handle two kinds of asphalts. Then, they were regenerated by regenerants which were developed above. The paper mainly concluded:Petroleum-based regenerant based on components blending mechanism, and it was prepared by 90# base asphalt, mineral oil and polymer X, simultaneously, this paper studied the storage stability of regenerant which had good regeneration effect. Test results showed that, S-PJ-3 recycling agent had the best regeneration effect, at the same time, it was reserved at the condition of 90℃,48 h, test results showed that its viscosity separation was very small, and it had good storage stability and stable characteristics. Vegetable oil-based(tung oil, castor oil, rapeseed oil, linseed oil) regenerants based on solubilization-dispersion mechanism, and they had good regeneration effect on aged asphalt when mass ratio of vegetable oil regenerant was m(vegetable oil):m(110# base asphalt)=30:100.Paper systematically studied conventional properties(penetration, ductility, softening point, viscosity, TFOT), in addition, adhesion, rheological properties and microstructure properties of regeneration base asphalts was studied by using ultraviolet spectrophotometer, dynamic shear rheometer, bending beam rheometer and gel permeation chromatograph, and they were contrasted with original asphalt. Test results showed that: Regeneration base asphalts could reach or approach to the level of fresh asphalt on conventional properties; Generally, adhesion of regeneration asphalts was better than fresh asphalt; High-temperature performance, low-temperature performance and temperature sensitivity of reclaimed asphalts were better than fresh asphalt. GPC test proved that molecular weight of aged asphalt decreased by adding regenerants, it also proved there was no obvious chemical reaction happened between the recycling agents and aged asphalt.At the same time, rutting, low-temperature bending and water stability test results indicated that pavement performance of regeneration asphalt concrete met the requirements of standard.Aged SBS modified asphalt could be effectively regenerated by A harmonic component and B modifier component. Test results showed that aged SBS modified asphalt would be effectively reclaimed by recycling agents of base asphalt and A component(which was prepared by 110# base asphalt, mineral oil/vegetable oil and SBS), and they could restored SBS modifier which was not completely aged in the aging process of SBS modified asphalt. At the same time, “secondary modification” by B modifier component(which was prepared by DS-MPA and S) was adopted to increase the properties of reclaimed SBS modified asphalt.