Optimization of geocomposites for double-layered bituminous systems

In order to improve pavement service life, reinforcement systems can be employed in asphalt layers. In this regard, geocomposites obtained by combining geomembranes with geogrids represent a promising option because they should allow both waterproofing and improved mechanical properties of asphalt pavements. However, the presence of reinforcement may cause an interlayer de-bonding effect that negatively influences overall pavement strength. Given this background, the present research aimed at evaluating the effectiveness of pavement rehabilitation with geocomposites in the laboratory. In particular, the present experimental study intended to implement new products by selecting the optimum combination among different geomembrane compounds, reinforcement types, reinforcement positions and interface conditions. The laboratory investigation was preliminarily organized to perform interface shear tests by means of the ASTRA apparatus. Then, on the basis of the results of the previous phase, the more promising configurations were selected to be further evaluated by means of the three-point bending tests. Specimens were obtained from double-layered slabs compacted in the laboratory. The results presented in this paper enabled the preliminary tuning for the selection of optimized composites to be submitted, in the near future, to performance-related dynamic tests and in situ monitoring of real scale trial sections.