ABSTRACT
The use of bituminous layers in railway tracks contribute to improve the mechanical performance and durability of superstructure as long as this structural layer preserves its properties. However, the bearing capacity and settlement ratio of the track bed under such bituminous layers can play an essential role on its structural performance and fatigue life, and therefore, this fact must be considered when designing the track section. In this sense, this paper focuses on the evaluation of the mechanical performance and fatigue life prediction of different types of bituminous materials for railway over simulated track beds with diverse strength. Particularly, it was used an innovative laboratory device that allows for reproducing various conditions of bearing capacity and settlement ratio for the support of the bituminous layers during fatigue tests reproducing traffic efforts through repetitive loads over the asphalt. Results show the correlation between the stiffness of the track bed and the durability of the bituminous layers, determining the type of asphalt more appropriate depending on bed performance. Similarly, it was seen that the higher the ratio of track bed settlement, the shorter the fatigue life of the bituminous material, leading to the cracking of fragile materials while ductile bituminous layers showed higher capacity to absorb the deformation of track beds.
