NJDOT Research
This study focused on evaluating the field performance and life expectancy of various asphalt overlay treatments commonly used in New Jersey through full-scale accelerated pavement testing. Six 30-ft. long and 12-ft. wide full-scale, composite field sections were evaluated in this study. All six field sections contained a similar substructure (i.e. 8-in. thick Portland cement concrete (PCC) base, 16-in thick New Jersey I-3 (A-1-a) granular subbase, and 12-in. thick compacted natural soil subgrade). The overlay on the test sections consisted of the following mixes a 3-in. thick 9.5ME Superpave mix for Section 1, a 3-in thick Stone Matrix Asphalt (SMA) mix for Section 2, and a 2-in. thick New Jersey High Performance Thin Overlay (NJHPTO) for Section 3. The overlays on sections 3 through 6, consisted of a combination of 1-in. thick layer of BRIC and a 2-in. layer of 9.5 ME Superpave, SMA, and NJHPTO, respectively. All sections were instrumented with two asphalt strain gauges, linear variable differential transformers, soil compression gauges, and one pressure cell. The test sections were subjected to accelerated pavement testing at the Rowan University Accelerated Pavement Testing Facility (RU-APTF) using a Heavy Vehicle Simulator (HVS). The accelerated pavement testing involved the application of 60-kN, dual-tire, single axle load configuration for 200,000 repetitions. The test sections were also evaluated through heavy weight deflectometer testing and transverse pavement profile assessment. A ranking system was developed to determine which asphalt overlay had the best overall field performance. Based on the ranking system, it was concluded that section containing the SMA overlay had the best overall performance followed the sections containing the 9.5ME, NJHPTO, 9.5ME and BRIC combination, SMA and BRIC combination, NJHPTO and BRIC combination. It was also found that the addition of a 1-in. layer of BRIC did not significantly improve the field performance of the overlays.
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