The effect of crumb rubber on the asphalt mixture properties

Abstract

Crumb rubber for asphalt mixture modification can be used in two ways: incorporate to bitumen (wet process) or incorporate to aggregate (dry process) mixture before adding bitumen to mixer. Wet process has some disadvantages related to need of reasonable modification of asphalt plant. Dry modification process has more potential due to more simple technology and possibility to add higher quantity of crumb rubber comparing to the wet process. The performance of crumb rubber modified asphalt mixture mainly depends on several factors as crumb rubber type, content and rubber particles size. However, limited number of publications reported the results of dry process crumb rubber modified asphalt mixtures performance. This paper analyse the effect of different amount of crumb rubber on modified asphalt mixture air void content, water sensitivity and stiffness. Test results revealed the effect of crumb rubber and maximum recommended amount for asphalt mixture modification by dry process.