01122013

Component

The Pavement Test Track is a full-scale, accelerated performance test facility for flexible pavements managed by the National Center for Asphalt Technology (NCAT) at Auburn University. Forty-six unique 60 meter test sections are installed around a 2.8 kilometer oval and subjected to accelerated damage via a fleet of tractors pulling heavy triple trailers. Methods and materials that produce better performance for research sponsors are identified so that future pavements can be selected based on objective life cycle comparisons. Using three sections built for the third cycle of testing, NCAT was asked by the research sponsor to compare the construction and performance of permeable surface mixes containing two different aggregate sources that were placed with conventional and dual layer paving equipment. All three sections were placed on perpetual foundations to ensure that distresses would be isolated to the experimental surface mixes. Two sections were placed with a conventional single layer paver, one containing cubical aggregates and the other containing more flat and elongated aggregates. The third section was built using the same slightly flat and elongated aggregates; however, the surface consisted of a thin 9.5 mm drainable mix over a thicker 12.5 mm drainable mix. By using an imported dual layer paver of European design, it was possible to place both drainable mixes simultaneously without applying an intermediate tack. The purpose of the 9.5 mm upper mix is to prevent debris from clogging the void structure of the lower 12.5 mm mix, which would have a negative impact on drainability performance. A competitive bidding process was used to select the contractor that produced all the mixes and also paved the two conventional single layer sections. A German crew was provided by the equipment supplier to operate the imported paver and place the drainable mixes on the dual layer section. All laboratory and field construction quality data generally met the expectations of the research sponsor. Laboratory permeability and bond strength testing were run on samples cored form the surface of the Track. Natural rainfall events were used to subjectively assess the drainability performance of each section during actual fleet operations. The section built with slightly flat and elongated aggregates appeared to exhibit more effective drainability than the section built with the more cubical aggregates, and the dual layer pavement appeared to exhibit more effective drainability than the conventional single layer drainable surface.

01120148

09-3744

English

25p

2009

Transportation Research Board 88th Annual Meeting

DVD

Figures; Photos; References (3) ; Tables (4)

Asphalt mixtures; Construction; Drainage; Flexible pavements; Pavement layers; Pavement performance; Paving; Permeability; Runoff; Test tracks

Georgia

Construction; Highways; Pavements; I52: Construction of Pavements and Surfacings

Transportation Research Board Annual Meeting 2009 Paper #09-3744

PRP, TRIS, TRB

Jan 30 2009 8:10PM