Life Cycle Assessment Applied to Circular Designed Construction Materials

摘要

Following the Waste Framework Directive, new solutions must be identified for the management of Construction and Demolition waste. Circular economy would provide the strategic key for addressing this issue: construction industry may, in fact, become an elective consumer of its own waste, where construction materials are circular and eco-designed. A comprehensive case study has been built, starting from evaluation of different management options for this waste to be applied in the municipality of Bologna and prosecuting with the design of concrete mixes, implementing construction and demolition derived aggregates as partial replacement for natural aggregates. Life Cycle Assessment (LCA) has been applied to evaluate the environmental impact of the options designed, in comparison with standard concrete already on the market. In particular, 25% replacement of natural aggregates leads to almost equal decrease in respiratory inorganics related impact and more than 39% decrease in land occupation indicator, even though ozone layer depletion impact indicator shows a negative performance. Nevertheless, partial aggregates replacement should be coupled by a limited cement replacement, in order to trigger a substantial decrease of the environmental impact in concrete production.