01518314

Component

Using scrap tires as a modifier for asphalt materials can be a practical solution for repurposing the waste material such as passenger and truck tires. The use of scrap tires as a modifier for asphalt binder requires that the waste material be ground to a fine crumb-like size which is commonly referred to as ground tire rubber (GTR) modifier. States are becoming more receptive to incorporating GTR in asphalt mixtures as the price of polymer-modified binders has increased over the past years. For GTR-modified binders to become more widely accepted, they need to be evaluated in different mixture types. This research project designed and compared the performance of seven open-graded asphalt mixtures which contained different GTR products and styrene-butadiene-styrene (SBS). These mixtures were compared for draindown potential, rutting susceptibility, durability, and permeability. The results of this research showed that GTR was commonly successful in providing adequate draindown resistance without fibers in the mix. Additionally, all mixtures showed adequate performance to pass the asphalt pavement analyzer (APA) rutting test and Cantabro durability test. Only one mixture failed the Hamburg Wheel Tracking test; however, it used a micronized rubber powder (MPR) which may have provided more rubber digestion, resulting in higher asphalt binder contents, as indicated by its superior Cantabro result. Overall, GTR was shown to be an allowable substitute for SBS in open-graded mixtures as long as proper testing is conducting during the mixture design to ensure rutting resistance and draindown resistance if fibers are removed from the mixture.

This paper was sponsored by TRB committee AFD70 Pavement Rehabilitation.

01503729

14-4238

English

15p

2014

Transportation Research Board 93rd Annual Meeting

Digital/other

Figures; References; Tables

Asphalt mixtures; Crumb rubber; Durability; Mix design; Open graded aggregates; Permeability; Rutting; Styrene butadiene styrene

Draindown; Scrap tires

Highways; Materials; Pavements; I23: Properties of Road Surfaces; I31: Bituminous Binders and Materials; I35: Miscellaneous Materials

Transportation Research Board Annual Meeting 2014 Paper #14-4238

TRIS, TRB, ATRI

Jan 27 2014 3:27PM