Using Crumb Rubber to Improve the Bituminous Mixes: Experimental Investigation of Rutting Behavior of Flexible Asphalt Mix for Road Construction

Abstract

Tires that are simply thrown away are a serious environmental problem and safe disposal is a difficult problem. Using the crumb rubber (CR) obtained from shredding of those scrap tires in roads is an alternative solution to their safe disposal. On the other side, excessive rutting in the bituminous layer is a structural defect associated with functional implications. Wheel loads and high pavement temperatures are environmental factors which the main cause of premature rutting. Modified binders and rut resistant mixes especially gradations can reduce premature rutting. The object of the paper to solve two main problems: firstly, the solution to the problem of the tires waste to safe disposal and; secondly, to study the rutting behaviour in bituminous mixes modified by tires waste in CR form. In this paper, two types of bituminous mixes, stone matrix asphalt and bituminous concrete those are used to carry wheel tracking test. The results are shown by using Marshall Test that 6% of CR content by weight if normal binder 60/70 content and optimum binder content for the binder in bituminous mixes is 5.1% & 5.5% by weight of mix is have improved the bituminous mixes. In addition, results indicated that the mixes prepared with a modified binder by CR are good in forming rut resisting mixes. The benefit of this study is the tires waste disposal in an environment-friendly way and better road to withstand rutting.