Rutting Resistance of Asphalt Mixes Containing Highly Modified Asphalt (HiMA) Binders at the Accelerated Pavement Load Facility in Ohio

Abstract

Highly modified asphalt (HiMA) mixes have been proposed as a stronger alternative to standard asphalt concrete mixes that will enable thinner perpetual pavements in Ohio. HiMA uses a polymer-enhanced binder has a higher unit cost, but has the potential to reduce the thickness of perpetual pavements, resulting in savings compared to conventional HMA perpetual pavement projects. Test sections containing HiMA in the surface, intermediate, and base layers were constructed with total thicknesses of 20, 23, and 25 cm, created by varying the depth of the AC treated base, in the Accelerated Pavement Load Facility (APLF) at Ohio University in Lancaster, Ohio. An additional 28 cm section was installed as a control with a non-HiMA base layer and HiMA surface and intermediate layers to compare with the experimental sections. Each pavement was subjected to 10,000 passes with a single axle load of 40 kN while the pavement was held at each of two pavement temperatures of 21.1 and 37.8 °C. Rutting on the surface of the pavement was measured using a rolling wheel profilometer after 100, 300, 1000, 3000, and 10,000 wheel passes at each temperature. The four sections showed no significant rutting damage after being subjected to a total of over 20,000 passes, and remained well below ODOT’s “low rutting” threshold of 3.2 mm. Extrapolating the rutting data indicated the worst-performing section would reach the low rutting threshold after more than a million passes of the load. The rutting data were compared to those obtained in a previous perpetual pavement study in the APLF that had surface courses including Aspha-min warm mix asphalt and a conventional hot mix asphalt, which crossed the low rutting threshold well before 10,000 passes at the high temperature.