Technical and economical comparison of concrete bearing layer and asphalt bearing layer in balastless superstructure

Nowadays, the use of ballastless railway superstructure has been becoming increasingly widespread. The reduction of the height of the superstructure, as well as decrease in the need for maintenance is also important factor for this. Thus, construction costs are considerably reduced especially in constructions such as tunnels and bridges. Considering the ballastless superstructure types and the superstructure types of line lengths used worldwide, it is clear that scientists pay attention and spend time to improve this system. A Standard ballastless superstructure consists of rails and rail fastening elements, sleepers, concrete or asphalt bearing layer, water-proof hydraulically-bonded layer, frost-proof layer and substructure. As is known, the most commonly used layer in the balastless tracks is the one made of concrete. Nowadays, asphalt bearing has began to gain importance too. Many reasons for using asphalt material in railway as well as highway as bearing layer can be suggested. One of the most important reasons is that asphalt is a more flexible material, thus it adapts to compelling circumstances. Another factor is not to require cure times of the asphalt, thus the production can be performed quickly. In this study, balastless systems with asphalt bearing layer and concrete bearing layer are compared in terms of technical and economical aspects. Also, the construction and maintenance costs of the systems were calculated on Yenibosna-Airport metroline and compared with each other. According to comparison results, concrete bearing layer is 25% more economical than asphalt bearing layer in terms of construction costs and 18% more economical than asphalt bearing layer in terms of total costs.