Design Calculations for Embedded Rail in Asphalt

In built-up areas, embedded rail structures have more advantages than conventional paved-in tramways. In the Netherlands, embedded rail structures are constructed solely of cement-bound concrete. These structures perform perfectly under both road and rail traffic and have significantly reduced noise and vibration in the tramway environment. Cement-bound concrete is, however, not applicable in all circumstances. To expand the applicability of embedded rail, the possibilities of embedded rail in asphalt (ERIA) were investigated. Cement-filled, porous asphalt was considered as the bitumen-bound alternative for cement-bound concrete. To determine if ERIA is feasible, the study first examined the stresses and strains that develop in cement-filled porous asphalt and in the bedding mass. The stresses and strains were determined for representative road and rail traffic loading by numerous finite element models. For both the asphalt and bedding mass, material design requirements were calculated. The mechanical properties of the materials were then studied to determine whether or not the materials comply with the design requirements and are suitable for application in this new type of embedded rail structure.