Test Research On Waste Plastics And Crumb Rubber Composite Modified Asphalt Mixtures

The waste crumb rubber and plastics composite modified asphalt mixtures were used in asphalt concrete pavement. It not only turned waste into wealth, reduced the black and white pollution in environment, but also improved the performance of asphalt pavement. This way would have significant benefits, including economic benifit, social benefit and environmental benifit.Based on Singapore Shell 70# base asphalt, the asphalt was composite modified by crumb rubber of 30 mesh and waste plastics(waste PP particles and waste PVC powder) through laboratory test in this paper. First, waste plastic and crumb rubber composite modified asphalt binders with best performance were prepared by using orthogonal experimental design method. The preparation scheme of waste PP and crumb rubber composite modified asphalt: crumb rubber with 20% content and waste PP with 2.5% content, mixing 1h in 190℃. The preparation scheme of waste PVC and crumb rubber composite modified asphalt: crumb rubber with 20% content and waste PVC with 3.0% content, mixing 1h in 190℃. On the basis of properties study, the reaction mechanism of waste plastics and crumb rubber composite modified asphalt was investigated.Next, the pass rates of sieve pores 0.075mm and 2.36mm were adjusted correspondingly according to the traditional gradation of SMA-13. The gradation curve of waste plastics and crumb rubber composite modified asphalt mixtures was obtained. Through Marshall test, the proportion design of waste plastics and crumb rubber composite modified asphalt mixtures SMA-13 and AC-13 were carried out. And the proportion designs of SMA-13 and AC-13 were checked.Then, the various performances of waste plastics and crumb rubber composite modified asphalt mixtures with different gradation(SMA-13 and AC-13) and different preparation processes(wet process and dry process) were analyzed. Relative to pure asphalt-rubber mixtures, the superiority of waste plastics and crumb rubber composite modified asphalt mixtures were verifed further.At last, the economic analysis and comparison of waste plastics and crumb rubber composite modified asphalt mixtures were evaluated.