Analysis of Double Edge Notched Tension Test and Multiple Stress Creep Recovery Test Ability to Predict HMA Fatigue Performance

摘要

The addition of polymers to asphalt binder has allowed for the enhancement of hot mix asphalt (HMA) ratting and fatigue performance. In Ontario, the performance of polymer modified asphalts (PMA) is evaluated by using the double edge notched tension (DENT) test and multiple stress creep recovery (MSCR) test. In order to understand whether these performance characteristics correspond to asphalt mixture properties, this paper examined the relationship between HMA fatigue performance, percent recovery and two DENT test properties. Four-point bending beam fatigue (4PB) testing on HMA samples showed that there is a poor correlation between the critical crack tip opening displacement (CTOD) and the 4PB properties. Several other DENT test properties have also shown an inability to differentiate various levels of polymer modification. The results have shown that there is a positive correlation between the percent recovery of the asphalt cement and the fatigue properties. The addition of polymer increased the 4PB fatigue life of asphalt mixture, but the magnitude of the increase also depended on the nature of the source binder. This testing has added evidence to the notion that the DENT test may not effectively evaluate the performance of PMAs.