Optimization of Fatigue Cracking Resistance of Costa Rican Asphalt Concrete Mixes

Fatigue cracking is a common distress in Costa Rican asphalt concrete, and yet current specifications on materials and structural design do not address it. This report presents numbers of repetitions to failure of several experimental treatments, tested by the flexural beam test. Each treatment is the result of a combination of a representative aggregate source (one from the Eastern shore and two from the Central Region) as well as mix type (either dense graded with AC30 binder, dense graded with SBS modified AC30, stone matrix asphalt with AC30 or stone matrix asphalt with PG 70 – XX), and controlled strain (400, 500, 600 x 10-6 mm / mm). Test strain levels were determined based on a multi-layer elastic analysis of several typical pavement sections, so that representative strains under actual loading were selected. After mixing, short term oven aging, compaction, long term oven aging, and sample cutting, a flexural beam test at 20°C was performed on all 72 specimens; so that 36 experimental treatments were considered, each tested twice (two replicates). As a result of all available results, an analysis of variance was performed, so that not only was it found that aggregate source, type of mixture and strain had significant effects on number of repetitions to failure, but also their interactions (cross products) were found highly significant. Additionally, linear regression analysis techniques were employed to select fatigue cracking transfer functions. Consequently, separate models were obtained to convert strain and mix properties to number of repetitions to failure of both dense graded and stone matrix asphalt mixes.

Language

  • English

Media Info

  • Media Type: CD-ROM
  • Features: Figures; References; Tables;
  • Pagination: 29p
  • Monograph Title: TRB 86th Annual Meeting Compendium of Papers CD-ROM

Subject/Index Terms

Filing Info

  • Accession Number: 01044192
  • Record Type: Publication
  • Report/Paper Numbers: 07-1828
  • Files: TRIS, TRB
  • Created Date: Feb 8 2007 6:32PM