Experimental Research On Characteristics Of New Crumb Rubber Asphalt Mixture

Rubber industry has developed rapidly since the new century. Waste rubberproduct increases daily. Recycling of waste rubber products has become a pressingproblem, especially for scrap tyres. Many researchers have carried on a large amountof research to it. Rubber tyres crush into particles paved road is one of the mainmethods for recycling waste tyres. In this paper, rubber particles were added in theform of aggregate in asphalt mixture, which formed granulated crumb rubber asphaltmixture. The characteristics of asphalt mixture were tested. The results have practicalvalue in engineering project.Based on AC-13continuous dense gradation of granulated crumb rubber asphaltmixture, water stability of different grade road cases was studied. In the first gradehighway asphalt mixture, research shows that splitting strength of asphalt mixture arereduced before and after freeze-thaw when adding rubber particles and the freeze-thaw split intensity ratio is greater than80%for1-2mm granulated crumb rubberasphalt mixture. It meets the specification requirements. In low grade road asphaltmixture, the compactness of the specimens increases and the voidage decreases withincrease of the fine aggregates, which improve the water stability of asphalt mixture toa certain extent.Through the freeze-thaw cycle test, durability of granulated crumb rubber asphaltmixture with different dosage of rubber particles in asphalt mixture was studied underthe condition of freeze-thaw cycles. Applying the gray system theory, the result of theexperiment analysis was predicted. Research shows that voidage of asphalt mixturehas more important influence on the splitting tensile strength. The appropriate dosageof rubber particles can also obtain good durability. GM (1,1) model has goodreliability for predicting the short-term development of splitting tensile strength andvoidage of asphalt mixture under the condition of freeze-thaw cycle. Through low temperature bending test, the low temperature crack resistance ofgranulated crumb rubber asphalt mixture was studied. The introduction of strainenergy density value which comprehensive assessed the low temperature crackresistance of asphalt mixture. Research shows that the destruction of granulated crumbrubber asphalt mixture specimen micro strain is more than2300while adding rubberparticles, which meets the technical indicators of winter cold area. Bending strainenergy density value of asphalt mixture is largest with1%rubber particles volumefraction. And it has good low temperature crack resistance. With the decrease oftemperature, the maximum flexural strength increases, bending tensile strain isreduced and the stiffness modulus increase when the asphalt mixture specimens havebeen destroyed.