Development of a testing temperature to be used with the hamburg wheel tracking device on asphalt mixtures that utilize performance grade binders

The Hamburg Wheel Tracking Device (HWTD) is used in the laboratory to evaluate an asphalt mixture's potential for failure in the field. This test observes damage due to rutting and moisture susceptibility on a prepared asphalt sample. The test is generally run at 50° C regardless of the type of mix or the grade of asphalt binder used in the mixture. This work evaluates the effect that test temperature has on HWTD test results, and their relation to mixture performance. Slabs were prepared using a linear kneading compactor and tested in the HWTD at multiple temperatures. Three binder grades were evaluated, a PG 58-28 unmodified, a PG 70-28 modified with polymers and polyphosphoric acid (PPA), and a PG 64-28 obtained by blending the PG 70 and the PG 58. The binders were obtained from different sources common to the state of Utah resulting in a total of six binder combinations.