Study On The Modified Asphalt By Recycled Plastic

Asphalt is a flexible, plastic and viscous rheological material which is fluid when soften at high temperatures and is solid when harden and become brittle at low temperature. But road surface requires the asphalt which will not be easy to get soft to generate the rut at high temperatures and which will not be easy to get hard and brittle to crack at low temperature. But generally, asphalt hardly meets the mutually contradictory and resistant demands that are the asphalt with good high temperature properties get hard and brittle at low temperatures, conversely, the asphalt with a good crack resistance at low temperatures often softens and flows at high temperatures. This leads to the research, production and application of the modified asphalt. Modified asphalt is a kind of asphalt binder made by adding the rubber, resins, macromolecular polymer, fine ground rubber powder or other filler doped extrinsic agent (modifier)into the asphalt to improve the performance of the asphalt. Now commonly used modifiers can be divided into three categories: rubber products, thermoplastic rubber and resin type. Plastic modifier can be effective in improving high temperature performance of asphalt, but it's expensive. Therefore, the recovery of waste plastic modified bitumen can not only make full use of resources, but also address the serious environmental problems. As there are differences between the waste plastics and asphalt in the molecular weight, density, viscosity and chemical structure differences, matrix asphalt and waste plastics are difficult to miscible under simple mechanical ageing test, and the storage stability is poor. Therefore, it is positively and practically valuable to study the compatibility stability of waste plastics and asphalt and develop waste plastic modified bitumen with good compatibility stability.This article is on the optimum technology condition of the preparation of waste plastic modified asphalt and the properties of modified asphalt. And it finds out the methods of the optimum technology condition of the preparation of waste plastic modified asphalt and resolving the storage stability of the waste plastic modified asphalt. The main content is as follows:1. evaluate the conventional performance of asphalt2. determine the dosage, optimum process parameters and basic properties of the waste plasticDetermine the variation of the properties of modified asphalt with the amount of modifier; select the appropriate amount of the PE, PP.At different process conditions (such as cutting frequency, cutting time, cutting temperature, etc.), a series of PE, PP modified asphalt samples are prepared. Through the evaluation of the fundamental properties of modified asphalt, the optimal process parameters are determined, and the conventional properties of the modified asphalt prepared under optimum conditions, micro-structure, infrared spectra are analysis.3. research the decentralized properties of the stored modified asphalt, for the bad Storage stability of modified asphaltStoring modified asphalt at 135℃for 20 hours; 163℃for 48 hours and stirring for a certain time, then testing the properties of test samples, and studying through micro-microscope, to proof that if the properties of the modified asphalt by PE, PP stored a certain time can basically return to the state before it is stored.4. fill method to improve the storage stability of modified asphalt by waste plasticReducing the density difference between bitumen and plastic modifier, scilicet, a greater density of matrix used filling plastic; in order to increase the density difference between the plastic and asphalt, increase the stability of plastic particles in the asphalt.5. determining the optimum process parameters of the parent method used modified asphalt by waste plastics and the basic properties of modified asphaltThrough the comparison of softening point, penetration, and the fundamental properties of the aged asphalt of modified bitumen prepared with different process conditions and the experimental results of the optimization, the best process conditions was selected. And the conventional properties, micro-structure, infrared spectra of the modified asphalt prepared under optimum process conditions were analysis.