The Study on the Asphalt Mixture with Large Quantity of Rubber
|Course||Road and Railway Engineering|
|Keywords||road engineering asphalt mixture modified asphalt the modified asphaltmixture with large quantity of rubber powder the piston model flexible aggregate drymixing process|
The content of rubber powder only accounts for0.85%~1.27%of ordinary rubberasphalt mixture, and most of the research focus on the wet method and the pavementperformance of rubber asphalt mixture from the aspect of modified asphalt. The paper usesanother construction technology-dry process, the method is that directly adding a largenumber of new rubber powder material in asphalt mixture, where a part of the rubber powderis used to modify the asphalt, and most of the rubber powder scatter in the asphalt mixtureacting as a flexible aggregate. Research on various pavement performance of the asphaltmixture with large quantity rubber is undertaken, and the piston model theoretical is adoptedto analyze performance mechanism about the large amount asphalt mixture performance.The paper focuses on the study of mix proportion design, high-temperature performance,low-temperature performance, dosage of rubber dimensional joint asphalt mixture, technologyand social benefits. The design idea of asphalt mixture with large quantity rubber is proposedin the study of Mix proportion design, and the indicator and preparation method is madeaccording to the characteristics of mixture, finally the rubber asphalt mixture with3.24%rubber powder is designed according to the selected grading. The selected rubber asphaltmixture shows excellent high temperature performance and low temperature pavement, andthe high temperature stress of piston model is proposed through the study on the hightemperature properties of mixture; The mixture performs good flexibility under the lowtemperature, which is different from the ordinary mixture that performs brittle failure. Ofcourse, the excellent anti-cracking performance of the mixture is not only related to themodified asphalt, but also because there is a quantity of rubber powder which acts as theflexible aggregate. Amount of rubber in asphalt mixture to replace rubber powder wasadopted, using the chemical reaction between the intensive degree of the interaction of rubberpowder and asphalt, rubber powder material for asphalt mixture modified effect. Test resultsshow that economic and reasonable dosage of the new material is20%. The optimum processof mixture is: the best mixing temperature ranges from165℃to175℃(asphalt-aggregateratio4.3%~4.5%), the best mixing time is60s+90s+90s, and the best time for tightness is 30min. Under this condition, comparing the rubber asphalt mixture of20%dosage with thezero dosage of rubber dimensional joint asphalt mixture, the high temperature stabilityperformance is increased by13.6%and the low temperature performance is improved by27.8%.