SUSTAINABILITY IN RAILWAY CONSTRUCTION: LCA–LCC BASED ASSESSMENT OF ALTERNATIVE SOLUTIONS FOR TRACK-BED

The economic and environmental sustainability of the Bitumen Stabilized Ballast (BSB) as construction and maintenance practice in railway track-bed is evaluated in comparison to the traditional ballast (TB). This aim is achieved integrating the results of an attributional Life Cycle Assessment (LCA), following a cradle-to-grave approach, and the Life Cycle Cost (LCC) analyses. The higher durability of BSB leads to arise environmental benefits in almost all the impact categories of LCA. Nevertheless, Bitumen Emulsion (BE) originates high level of impact on certain categories and they cannot be compensated by the reduction of the minor and major maintenance activities required by the BSB solution over the life cycle. The results of the LCA have been implemented in the LCC model for accounting the external costs due to the environmental impacts. From this analysis it emerges that the BSB technology, used since the construction stage and during the routine tamping, can provide economical savings.