Research On Properties And Modification Mechanisms Of Domestic Waste Old Plastic Modified Asphalts

Based on the present research of domestic waste old plastic modified asphalt both in our country and outside, this thesis studies two kinds of processing plastics. The one is produced by simple regeneration process and extrusion machine, which called recycled plastic (RP) in this paper. The other one used RP as raw material and obtained by pyrolysis process, which called cracking recycled plastic (CRP).This paper adopts the method of experimental study in combination with theoretical analysis to discuss the two kinds of waste old plastics modified asphalts’ properties and modification mechanisms.①This study using infrared spectroscopy and thermal analysis identifies four recycled plastic particles’ major components and four cracking recycled plastics’ main character.②Through waste old plastics modified asphalts’ egregation tests, this paper finds CRP modified asphalts’ storage stability is much better than RP modified asphalts.③Owing to waste old plastics modified asphalts’ softening point tests and rotational viscosity tests, this thesis considers the two types of waste old plastics modified asphalts’ high temperature property are increased, with RP modified asphalts’ viscosity coefficient and temperature coefficient are better than CRP modified asphalts.④Based on waste old plastics modified asphalts’ rotational viscosity tests, this paper confirms the two kinds of waste old plastics modified asphalts’ best mixing temperatures and compaction temperatures.⑤By waste old plastics modified asphalts’ ductility tests and bending beam rheometer tests, this study reachs a conclusion that two types of waste old plastics modified asphalts’ low temperature property are decreased, and RP modifier reduced ductility lower than CRP modifier.⑥Found on waste old plastics modified asphalts’ rotating thin film oven tests, this thesis draws the conclusion that RP and CRP modifiers both can increase asphalts’ aging property, making residual penetration ratio as the main indicator.⑦Because of waste old plastics modified asphalts’ infrared spectroscopies, this paper finds RP modified asphalts and CRP modified asphalts are dominated by physical modification, and no significant chemical modification.This thesis using infrared spectrum and thermal analysis systematic studies the two kinds of waste old plastics modifiers’ physical and chemical properties, indentifing the major components of RP and CRP, and more obtained the information about moleculer weight, molecular distribution, molecular strycture, thermal stability, chemical reactivity, crystallinity and melting point. When discussing modification mechanism, all of these conceptions are extraordinary useful acted as affect factors.