Characterization of Rubblized Concrete Pavements with HMA Overlays at the National Airport Pavement Test Facility

Abstract

Three rigid airport pavement test items (MRC, MRG, AND MRS) at the Federal Aviation Administration’s (FAA) National Airport Pavement test Facility (NAPTF) with 12-inch thick concrete slabs on different support systems (slab on crushed stone base, slab on grade, and slab on stabilized base) were rubblized with a resonant pavement breaker. All three test items were constructed on CBR 7 clay subgrade. After rubblization, the rubblized concrete was rolled and paved with a 5-inch thick P-401 (hot mix asphalt) overlay. Heavy-weight deflectometer (HWD) tests were performed using the FAA’s HWD equipment on a 10-foot (3.05 m) grid to study the uniformity of the pavement structures. The results showed that the pavement structure within a test item (for all rubblized test items) was fairly uniform. After the completion of uniformity tests, the overlaid pavements were subjected to full-scale accelerated traffic tests under the 4-wheel landing gear configuration (with wander) and 55,000-lbs (25-tonnes) wheel load. Straightedge rut depth measurements and transverse profile measurements were made at regular intervals during the traffic tests. No significant distresses were observed for 5000 passes after which the wheel load was increased to 65,000-lbs (29.5-tonnes) and 6-wheel landing gear was used for testing. The paper summarizes the results from pavement layer characterization tests, pavement structure uniformity from HWD tests and pavement performance during the traffic tests.