Use of bitumen-stabilised ballast for improving railway trackbed conventional maintenance

Despite its many advantages, ballasted track needs frequent maintenance to ensure an adequate quality of service. However, tamping, traditionally used to correct geometry, causes ballast degradation and loosening of the already compacted ballast layer, which quickly returns the track to its pre-maintenance position. Then, other maintenance techniques such as stoneblowing, as well as diverse solutions that reinforce trackbed, have been developed to reduce ballast settlement and particles degradation. Given the need to further advance research in this field, bitumen-stabilised ballast (BSB) has started to be investigated by the authors as a feasible solution thanks to its easy and quick applicability and relatively low cost of the bonding agent. Nonetheless, more in-depth laboratory full-scale tests are necessary to prove the effectiveness of this solution before its application in real trial sections. This paper focuses on investigating the effect of BSB application during tamping and stoneblowing, on trackbed performance. Various scenarios are analysed to evaluate the effectiveness of this technology when applied at different stages of ballast service (clean and fouled). The results show that the use of BSB could improve the effectiveness of maintenance, particularly in the case of tamping and at the early stage of ballast life