Laboratory characterization of temperature induced reflection cracks

A hot-mix asphalt (HMA) overlay is one of the primary strategy for rehabilitating existing HMA pavements and Portland cement concrete (PCC) pavements. The current design program, FAARFIELD, does not address reflective cracking for asphalt-overlaid concrete pavements due to its mechanism complexity. The bending, shearing, and thermal are three crucial factors to successfully model reflective cracking. To implement this failure mode in flexible over rigid design procedure, a series of full-scale test pavements were constructed, instrumented, and tested in the condition of extreme cooling temperature at the FAA National Airport Pavement Test Facility. The purpose was to assess cooling effects on the propagation of reflection cracks for airport AC over PCC pavements. In preparation for reflective cracking phase Ⅵ test, the FAA is conducting laboratory experiment on field extracted hot mix asphalt (HMA) cores. In order to test these field HMA cores, the Texas Overlay Tester (OT) was customized to get data similar to the full-scale tests. This paper discusses finite element analysis on the full-scale testing, development of the customized Texas OT, and a laboratory testing suite using the customized Texas OT, including preliminary tests, instrumentation, experiment design, and test results. Data obtained from this research effort will be used to develop a rational testing procedure to simulate extreme cooling cycles through full-scale testing.