Geocomposite-reinforcement of polymer-modified asphalt systems

Abstract

Geosynthetic reinforcement has proven to be an effective method to improve road pavement performance. In this regard, composite materials obtained combining bituminous membranes with reinforcing grids represent a promising option thanks to the waterproofing and stress-relieving effect produced by the membrane and the enhanced mechanical characteristics provided by the grid. This research had the objective of evaluating the effectiveness of pavement rehabilitation by means of an optimized composite material, consisting of an elastomeric bituminous membrane reinforced with a fiberglass grid, applied at the interface of a polymer-modified asphalt system. An unreinforced reference configuration was also investigated for comparison purpose. Interlayer shear tests and three-point bending tests were performed on double-layered specimens in order to evaluate bond strength at the interface and toughness (i.e. fracture resistance) of the pavement system, respectively. Shear tests showed that the reinforcement at the interface reduces the bonding between asphalt layers even if a residual cohesion contribution is provided after shear failure. As far as flexural properties are concerned, the real contribution of the reinforcement consists in the delay of crack propagation rather than in the inhibition of crack initiation.