01150936

Component

Reclaimed asphalt pavement (RAP) is currently a widely used material for the construction of asphalt pavements. However, in regions deficient in non-polishing aggregates, RAP is not commonly allowed in mainline surface courses for high volume roadways because of friction performance concerns. The goal of the present study was to determine the maximum amount of RAP that can be blended with high friction aggregates and used in surface mixes without significantly impacting their frictional properties. The initial part of the study described here included a comparison of RAPs collected from six different sources (mix plant stockpiles) in Indiana. It was shown that the field-collected RAP’s exhibited fairly consistent properties in terms of their gradations and binder contents. In the second part of the study, low friction aggregate (limestone) was used to produce a “worst case scenario” RAP, for evaluation of its influence on frictional characteristics of two types of hot mix asphalt mixtures: (a) dense graded asphalt (DGA), and (b) stone matrix asphalt (SMA). The DGA and SMA mixtures were produced with various amounts of this “laboratory-produced” RAP. The RAP was blended with two types of highly friction resistant aggregates: steel slag and air cooled blast furnace slag. Overall, the results suggest that for the materials and mixtures studied the maximum amount (threshold level) of RAP, which can be used in surface mixes without detrimental effect on their frictional properties, was about 30%. That addition level did not seem to depend on the type of aggregate present in RAP.

01147878

10-0434

English

15p

2010

Transportation Research Board 89th Annual Meeting

DVD

Figures; Photos; References (12) ; Tables (1)

Asphalt pavements; Bituminous materials; Dense graded aggregates; Field tests; Friction course; Hot mix asphalt; Limestone; Pavement performance; Polished aggregates; Reclaimed asphalt pavements; Stone matrix asphalt; Texture

Highways; Materials; I31: Bituminous Binders and Materials

Transportation Research Board Annual Meeting 2010 Paper #10-0434

PRP, TRIS, TRB

Jan 25 2010 10:14AM