Life Cycle Assessment of Mortars with Fine Recycled Aggregates from Industrial Waste: Evaluation of Transports Impact in the Italian Context

Abstract

An LCA study (based on ISO 14040, ISO 14044, and EN 15804 + A2 standards) was performed to evaluate the environmental impacts of two mortars incorporating recycled materials (composite and carbon dust) from industrial waste as fine aggregates. They were compared to “reference” mortars, with the same strength performance, entirely composed of raw natural materials. The aim was to advance knowledge on the performance of mortars with composite materials, especially deepening the impact of the phase of materials’ transport on life-cycle behavior. In this regard, the work was conducted in three phases. Firstly, the LCA was performed in a specific “local” production scenario. Then, a sensitivity analysis was carried out to assess the influence of the uncertainty of input data on the variance of LCA outcomes. Considering the high sensitivity of results to transport distances, the LCA was finally extended considering several scenarios with increasing distances of aggregates’ transport. The results demonstrate that, for all of the eleven impact categories considered, mortars with recycled aggregates perform better than reference mortars, mainly due to the higher weight of natural aggregates. Even considering an extreme scenario, where natural aggregates are produced in the mortar factory (aggregates’ transport distances set to 0 km, for reference mortars), mortars with recycled aggregates are still convenient from an environmental point of view, if distances for providing industrial waste are lower than 200 km. The promotion of a circular economy perspective, with the settlement of a network of local recycled materials’ providers and users can then generate important environmental benefits.