Investigation into stress states in porous asphalt concrete on the basis of FE-modelling

A new approach for the investigation of stress states in the asphalt-aggregate adhesive region and in the mastic of porous asphalt concrete (PAC) is presented in this paper. The method makes use of finite element (FE) modelling at meso-level. Hereto the geometry of PAC is simplified so that the main components (aggregate particles, mastic, interfacial zones and air voids) in the actual mixture are represented in the model separately. The visco-elastic Burger's model is used to simulate the response of the mastic consisting of fine aggregates and bituminous binder. The effects of the type of bitumen, traffic speed, degree of compaction, bitumen content and contact angle of packing are examined. Results demonstrate that the 2D model can be used to investigate stress states in the binder–particle interfacial zone and in the mastic. The FE-models give results that are in agreement with theoretical predictions. It is expected that the insights that are obtained via the discussed meso mechanical analysis of PAC will enable the development of a PAC mixture with a higher ravelling resistance.