Hydro-mechanical interaction in permeable pavement constructions under consideration of unsaturated states
The primary concern of this research is to provide a basis for the design of water-permeable road structures, whereby the effects of partial saturation on the stress-strain behavior of the individual layers of the road construction will be quantified and taken into account. Furthermore, it will be shown that by using Polyurethane (PU) as an alternative binder material the fatigue resistance and the durability of the bound road surfaces can significantly be improved. To fulfill the objectives, fundamental experimental investigations for both the mechanical and hydraulic behavior of the material in model and field scale have been undertaken in the first project phase. The results of the tests should be applied in the second project phase to calibrate the hydraulic and mechanical material laws. These should also be used in numerical analyses of the load-bearing behavior of water-permeable road structures to simulate the coupled mechanical and hydraulic behavior of the system under wheel load as realistic as possible. Recommendations for an optimized hydraulic and mechanical system behavior of the permeable road cross-section should be derived from the simulation results. In addition, in-depth experimental examinations are to be conducted: on the one hand, studies on the pore space of the porous layer using imaging methods are planned. Additionally, it is planned to identify the factors affecting drainage capacity. On the other hand, load tests with the mobile load simulator MLS30 should be done again to evaluate the influence of a high number of load cycles on the system and particularly on the PU-bound pavement layers.