Self-compacting recycled aggregate concrete using out-of-service railway superstructure wastes

Slab track is replacing obsolete ballasted track. This work proposes crushing out-of-service ballast and sleepers for use as aggregates for constructing the slab track. Three kinds of recycled self-compacting concretes were designed; the first one with aggregates from crushed ballast, the second one with aggregates from crushed sleepers and the third one with both kinds of aggregates in the proportion they appear in the track. The mechanical and durability properties of these concretes were analysed. The durability test was focused on freeze-thaw and drying-wetting cycles. The results obtained lead to the conclusion that out-of-service track could be used to build the new one, closing the loop. © 2019 Elsevier Ltd