Laboratory characterisation of optimised geocomposites for asphalt pavement reinforcement

ABSTRACT: In order to improve road pavement performance, reinforcement systems can be employed in asphalt layers. In this regard, composite materials obtained by combining bituminous membranes with fibreglass grids represent a promising option because they are able to allow both waterproofing and improved mechanical properties of asphalt pavements. At the same time, the presence of reinforcement at the interface inevitably causes a reduction of interlayer bonding that may negatively influence overall pavement strength. The present research had the twofold objective of evaluating the effectiveness of pavement rehabilitation by using geocomposites and identifying an optimised product. Particularly, the present experimental study intended to characterise three reinforcing materials produced by combining an elastomeric membrane with different reinforcement types and positions. Moreover, the prospective use of a tack coat at the interface was also evaluated. To achieve these aims, interface shear tests and both quasi-static and dynamic flexural tests were carried out on double-layered reinforced samples prepared in the laboratory. An unreinforced reference system was also investigated for comparison purposes. The experimental results showed that improved mechanical properties were achieved in the case of reinforced systems. This research study also provided useful suggestions for the production and utilisation of an optimised geocomposite for asphalt pavement reinforcement.