Circularity in the construction and demolition waste management chain

C&D waste represents 45.5% of the total production of special waste in Italy. Although the high recovery rate (78,1%), various regulatory, economic, technical, and cultural barriers prevent the widespread use of recycled aggregates (RAs) produced by C&D waste recycling activities. Among the limitations, market acceptance of products made using secondary resources as input material will only be ensured when their production costs are lower than those of virgin materials. Nevertheless, even more critically, the presence of impurities in the RAs and the difficulty in guaranteeing their consistent production preclude their use in structural concrete. To produce high-quality RAs, the waste entering the recycling plant must be as homogeneous as possible. Through selective demolition, a practice not very common in Italy, the materials can be carefully sorted, which is why it should be encouraged. The result of the three-year PhD provides a comprehensive study of the construction and demolition waste management (C&D) chain with the goal of fostering the circular economy (CE) in the construction sector through the implementation of tools useful to public administrations to encourage circular practices. The goal is achieved by implementing the Full-Environmental Life Cycle Costing (feLCC) methodology, which combines the Life Cycle Assessment (LCA) methodology with that of environmental Life Cycle Costing (eLCC) through the monetisation of environmental impacts. Based on the study results, it is possible to suggest incentive mechanisms in favour of small and medium enterprises (SMEs) for the execution of private demolition works. The project was developed in four successive macro phases, the application of the eLCC, the application of the LCA, the monetization of the environmental impacts and finally the definition of the proposals for the incentive mechanisms. The first research phase aimed to apply an eLCC to Lombardy's C&D waste management chain (Northern Italy). The investigated system includes all management phases of inert waste originating from demolition activities, from its generation at the end of building life, during an ordinary or selective demolition, to the treatment phase in a recycling plant, till the market re-placing as RAs. The inventory is implemented for each process in the management chain, with two surveys issued to demolition companies and C&D recycling facilities, respectively. It is feasible to obtain complete data for seven case studies on the demolition phase (with a response rate of 10.61%) and two mineral waste recycling facilities (with a response rate of 7.41%). The LCA study of the selective demolition phase is performed under the same boundaries as the eLCC system. The model is developed using SimaPro 9.3 with the Environmental Footprint 3.0 characterisation method, which evaluates 16 impact categories. The union between the eLCC and the LCA occurs through the monetisation process of the environmental impacts. Four different monetisation methods are selected, i.e., De Nocker e DeBacker, Smith et al., Stepwise, and Environmental footprint. Starting from the results obtained, the incentive mechanisms for the benefit of selective demolition and the use of recycled aggregates are defined. In particular, the identified cost items on which it is possible to apply a discount on the cost incurred by demolition companies and recycling plants are the demolition project, the on-site reuse cost, the recycling fee, and the sale of RAs. The incentives are supposed to be payable by Public Administrations through tax relief and/or non-repayable grants. The recipients of these incentives are the SMEs for the execution of private works. The final step is to conduct a feasibility analysis on applying the incentives described above to real case studies. Multiple conversations with Lombardy Area workers have determined which available funds might be spent for this purpose, and how much volume demolished every year can be entitled to incentives. In conclusion, although many challenges are experienced in gathering data appropriate for the eLCC, owing to organisations' lack of confidence in revealing sensitive data such as expenditures spent, the feLCC has proved to be a useful tool for identifying the criticalities of a value chain such as that of C&D waste.