A study on possibility of application of recent self-healing methods for self-healing concrete railway sleeper manufacturing: a review

Railway sleepers are under different types of dynamic, static, and impact loads. Due to a lack of a short span of track maintenance and inspection, damaged railway sleepers may not be detected and replaced after sudden damage. Cracks in concrete railway sleepers are almost inevitable and difficult to detect. According to the main role of sleepers to keep track of standard gauge and transfer loads to railway track interlayers, these damages may bring train derailment. Therefore, the application of self-healing methods can provide more lifespan time and compensate for some load capacity of damaged sleepers to extend their service life until they are inspected and removed from the track. Several self-healing methods have been proposed for large-scale beam shape structures, including autogenous and autonomous. But according to the special service condition of sleepers, most of these methods are not suitable for manufacturing railway sleepers. In this study, most of the available methods are reviewed and assessed based on the railway sleeper manufacturing process, service environment, loading condition, and lifespan. Finally, some prospective methods have been proposed to manufacture self-healing concrete railway sleepers such as the application of nanomaterials, vascular methods, and the LatConX system.