Effect of Reinforced Asphalt Pavements on Reflective Crack Propagation and Interlayer Bonding Performance

Reinforcement of asphalt pavements has become a valuable constructive method for preventing reflective cracking and prolonging the service life of asphalt pavements. Although the advantage of reinforcement overall seems beyond doubt, there is still insufficient information about the actual effect on the prolongation of the pavement's life-span. Further, it is not clear how the different grids affect the bonding performance between layers. This paper investigates the performance of different reinforcement grids on the performance of two layered asphalt pavements, mainly considering: (a) Reflexive crack propagation, (b) Shear bonding strength. The paper compares the performance of different non-reinforced and reinforced pavements, constructed in the laboratory and in the field and trafficked with a down-scaled (Model Mobile Load Simulator MMLS3) and a full-scale traffic load simulator (Mobile Load Simulator MLS10) respectively. Loading the pavements with rolling tires (cyclic loading) could show differences in the durability between the different reinforcement types as well as the improvement in the flexural bonding strength when using reinforcements compared to non-reinforced structures. Grid styles with different mesh opening sizes of 12.5 and 25 mm plus different tack coats or tack films were also considered. The investigation of the interlayer bonding strength was done by means of the layer parallel direct shear tester (LPDS) and 150 mm cores. It was found that the bonding properties do depend on the reinforcement type, but that in most cases the interlayer bond is according to the requirements.