Fatigue investigation of the interface shear performance in asphalt pavement

This paper shows the interlayer fatigue performance evaluated by the Sapienza shear testing machine. The tests can be performed by placing double layer specimens in several inclinations, in order to reproduce a variety of expected ratios between the normal and the shear stress. The machine manages loads with any kind of waveform and is particularly able to simulate the stress trends expected in field in points located just outside the wheel path. In this experimentation, the machine applies a triangular waveform load computed by a linear elastic multilayer program at the depth of the first pavement interface. A fatigue law is estimated considering the number of repetitions that causes the interface failure. A linear regression in the log-log graph suitably fits the experimental results for the analyzed conditions of temperature and interface type.