Accelerated Pavement Testing for Rutting Evaluation of Hot-Mix Asphalt Overlay under High Tire Pressure

Abstract

This study focused on the rutting characteristics of two typical hot-mix asphalt (HMA) overlays in airfield composite pavement under high tire pressure: asphalt concrete (AC) and stone mastic asphalt (SMA). To fulfill this purpose, accelerated pavement testing (APT) was implemented on the instrumented test field, and a series of laboratory tests, including density test, Hamburg wheel tracking test (HWTT), and uniaxial penetration test, were conducted based on 38 field drilled cores. The results from APT indicated that the shear flow was the main cause of rutting in the airfield composite pavement and the rutting only occurred within the HMA overlay. No densification was found from these two overlays. SMA overlay had more consistent rutting performance, higher shear strength, less uplift deformation and rut depth, and, therefore, higher antirutting potential compared with AC overlay. Furthermore, the bottom strain of SMA overlay was smaller at the beginning, but it increased as the loading cycles increase. Additionally, the rutting accumulation could be divided into two stages, and the first stage contributed more than 54% deformation to the total rutting. Tire pressure played a key role in the rutting of HMA overlay, and therefore higher tire pressure was recommended when studying airfield composite pavement’s rutting. Finally, the SMA overlay had cost advantage because of its longer service life.