Evaluation of permanent deformation of asphalt mixtures using different laboratory performance tests

• A new test was developed to evaluate the permanent deformation of asphalt mixtures.
• The fiber-reinforced mechanism for asphalt mixture was studied from microscopic view.
• We used a varying pressure in PTT to simulate the actual confinements in pavement.
• A correlation was analyzed between the test results from PTT and wheel tracking test.

The laboratory tests were conducted to evaluate the effects of polyester fiber on permanent deformation of asphalt mixtures. The results indicate the fibers improve the deformation resistance of mixtures. The confinements in the partial triaxial test (PTT) have significant effects on the permanent strain of mixtures. The varying confinement in the PTT better simulates the actual confinements in pavements. A stronger correlation of test results from the PTT and the wheel tracking test was found. It is concluded that the addition of polyester fibers improves the mechanical performance of mixtures, and the PTT method is a reliable new test method.