Full-scale study of Neoballast section for its application in railway tracks: optimization of track design

Neoballast, consisting of natural aggregates coated with rubber particles from waste tires, is postulated as an alternative type of ballast that can show higher resistance to breakage and frictional wear. However, as this innovative material also aims to improve track performance and durability, its application could lead to variations in fundamental track properties such as vertical stiffness, damping capacity, and settlement. This paper focuses on analyzing the effect of Neoballast on track section behavior as well as the optimization of its design in order to obtain deflections that are comparable to those measured with traditional ballast over both stiff and soft substructures. Results reflect that Neoballast allows for higher damping capacity, reduction in stress, and lower long-term settlement. Nonetheless, it leads to lower vertical stiffness, and therefore reduced thickness for this granular layer is required.