Utilization of 60/70 penetration grade asphalt on ballast structures with the variation of percentage and the number of pouring layers

Railroad ballast structure layer may experience a decline in mechanical and geometrical performance due to heavy train and environmental loads. In order to improve the quality of ballast structure, the addition of asphalt to ballast layer can be considered as a solution. Therefore, this research utilizes 60/70 penetration grade asphalt for ballast layer binding and stabilization. The objective of this study was to evaluate and analyze the mechanical behavior of clean-ballast and fouled-ballast layers with 2% and 4% penetration grade 60/70 asphalt poured in one (ballast surface layer) and three ballast surface layers. Compressive strength test was performed to analyze the weight of specimen, vertical deformation, and ballast material abrasion. The most prominent finding to emerge from this research was that the use of 60/70 penetration grade asphalt on ballast surface layer is crucial in retaining the load applied by UTM, in order to produce preferable load distribution to the entire ballast structure. It is found that, the higher the 60/70 penetration grade asphalt proportion and the more layers poured with asphalt, the stronger asphalt in reducing ballast abrasion percentage.