01044202

Component

Addition of fibers as reinforcement in asphalt mixtures has several benefits. In open graded mixtures such as permeable friction course (PFC) and stone mastic asphalt (SMA) addition of fibers is required to control drain down of asphalt binder during the laying and compaction process. According to the literature, addition of fibers to asphalt mixtures also results in improvement of mechanical properties of the mixture and consequently the life of the pavement. Various types of fibers are commonly used in asphalt mixtures. These include synthetic fibers, mineral fibers and cellulose fibers typically manufactured using various recycled material. The latter are commonly used in asphalt mixtures. Tire fibers are a waste byproduct of scrap tire treatment process, typically disposed in land fills. This paper presents results from a study to investigate the use of tire fibers in lieu of cellulose fibers. The overall objective of this study was to conduct a laboratory test program to examine the utility of by-product tire fibers in hot mix asphalt (HMA) for paving purposes. The test program included: two types of tire fibers (long and short), one cellulose fiber for comparison, and no fiber in control specimens; three different types of HMA mixtures (SMA, PFC, and coarse matrix-high binder); and five test methods (asphalt draindown, indirect tension test, dynamic modulus test, Hamburg test, and overlay tester) Researchers examined the availability of by-product tire fibers and found them to be readily obtainable in various parts of the United States. Laboratory test results indicate that recycled tire fibers can provide essentially the same or better benefits as cellulose fibers. These findings could open a new and significant market for these waste fibers and reduced demand on landfills.

01042056

07-1679

English

16p

2007

Transportation Research Board 86th Annual Meeting

CD-ROM

Figures; Photos; References (15) ; Tables (3)

Asphalt mixtures; Binder content; Binders; Dynamic modulus of elasticity; Friction course; Hot mix asphalt; Landfills; Recycled materials; Stone matrix asphalt; Tires

Asphalt treated permeable base; Indirect tension test

Highways; Materials; Pavements; Vehicles and Equipment; I23: Properties of Road Surfaces; I31: Bituminous Binders and Materials

Transportation Research Board Annual Meeting 2007 Paper #07-1679

TRIS, TRB

Feb 8 2007 6:21PM