Full-Scale Test of Thermally-Induced Reflective Cracking: Lessons Learned from 5-Year Research at FAA NAPTF

For a moderately deteriorated portland cement concrete (PCC) pavement where jet blast and fuel spillage are not a major concern, resurfacing the existing pavement with a relatively thin (less than 4 in) hot mix asphalt (HMA) layer provides an economic means of restoring or improving pavement life. The new asphalt concrete (AC) overlay unfortunately often fails before reaching its design life due to the occurrence of reflective cracking. In the early stages of development, reflection cracks may barely be visible and are not considered to be a structural problem. However, when they propagate through the pavement, infiltration of water can weaken the foundation and fine material may be pumped to the surface, resulting in the creation of voids beneath the concrete. Field experiences indicate that reflection cracks usually propagate into the overlay at a rate of approximately 1 inch per year and appear at the surface, in most cases, within 3 years or less. Thermally-induced reflective cracking is probably the most commonly accepted mechanism of reflection cracks. Temperature variations cause horizontal movements of the underlying PCC pavement joints. As a result, tensile stresses are induced in the overlay immediately above the joint/crack whenever contraction occurs. AC can relax under slow-moving conditions; therefore, considerable daily temperature changes have a far more instrumental role in the performance of HMA overlay than gradual seasonal temperature cycles. For instance, a number of reflection cracks were observed on the 18-month-old, 4-in.-thick AC overlaid PCC runway (1L-19R) at the Kansas City International Airport (KCI). Since the Southwest Boeing 737 was identified as the predominant aircraft loading at KCI, these reflection cracks appeared to be the result of fairly large local temperature swings.

Language

  • English

Media Info

  • Media Type: Digital/other
  • Features: Figures; Photos; References; Tables;
  • Pagination: 13p
  • Monograph Title: 2014 FAA Worldwide Airport Technology Transfer Conference Proceedings: Innovations in Airport Safety and Pavement Technology

Subject/Index Terms

Filing Info

  • Accession Number: 01538151
  • Record Type: Publication
  • Report/Paper Numbers: P10007
  • Files: TRIS, ATRI, USDOT
  • Created Date: Sep 9 2014 6:50AM