EFFECT OF COARSE AGGREGATE CONTENT ON STONE MATRIX ASPHALT RUTTING AND DRAINDOWN

The stone matrix asphalt (SMA) technical working group (TWG), composed of federal, state, and industry representatives, was formed in 1992. The SMA TWG developed the "SMA Model Material and Construction Guidelines". The model suggests using 20 to 28% passing the 4.75-mm sieve size. The effects of coarse aggregate content on the performance and draindown characteristics of SMA mixtures was evaluated. Performance was evaluated in terms of rutting using three wheel-tracking devices: the French pavement rutting tester, the Georgia loaded-wheel tester, and the German Hamburg wheel-tracking device. Draindown was evaluated using four tests: the German draindown test, the FHWA draindown test for open-graded friction courses, a proposed draindown test developed in the Bituminous Mixtures Laboratory at the Turner-Fairbank Highway Research Center, and the National Center for Asphalt Technology draindown test. Also, the effects of using a polymer instead of a fiber as the stabilizer in the SMA mixtures were examined. Data from the draindown tests and wheel-tracking devices showed that decreasing the coarse aggregate content reduced the amount of draindown without affecting the mixture performance in terms of rutting. When using a polymer instead of a fiber, the amount of mastic that drained down increased. On the basis of the Georgia loaded-wheel tester and the Hamburg wheel-tracking device, mixtures with the polymer had significantly lower rut depths than the mixtures with fiber. On the basis of the French pavement rutting tester, mixtures with the polymer had significantly lower rates of rutting (slopes) than mixtures with the fiber, but the rut depths at the end of the test were not statistically different.

Language

  • English

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 1-11
  • Monograph Title: Hot-mix asphalt design, testing, evaluation, and performance
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00714827
  • Record Type: Publication
  • ISBN: 309061563
  • Files: TRIS, TRB
  • Created Date: Dec 4 1995 12:00AM