Fatigue Experiments of Simulating Propagating Process of Reflective Cracking in Asphalt Concrete Overlays

In order to simulate reflective cracking of asphalt overlays or semi-rigid asphalt pavements in lab and evaluate the reflective crack resistance performance of with and without interlayer, a finite element analysis model based on the asphalt pavement, of which the semi-rigid base has cracked, is conducted and established through some basic assumptions in this paper. According to the results of pavement mechanical analysis and some literatures review, a laboratory reflective cracking simulation model was designed to compare the resistances of reflective cracking of different mixture samples. In order to compare the reflective cracking of different test samples, a dense grade asphalt mixture AC-20I with and without interlayer were used in the test. The results shows that asphalt mixture beams containing geotechnical fabrics can effectively delay the appearance of the reflective cracking at the bottom of the asphalt mixture beam and evidently reduce the propagation speed of reflective cracking while the beams containing geogrid can also hold back reflective cracking to a certain extent, but not as much as geotechnical fabrics did. It was proved that the model designed through finite element analysis (FEA) can simulate the reflective cracking caused by load and evaluate the reflective cracking resistance performance of different asphalt mixtures well and asphalt mixtures with fabrics can mitigate and delay reflective cracking effectively.