Evaluation of construction and demolition waste utilization schemes under uncertain environment: A fuzzy heterogeneous multi-criteria decision-making approach

The issue of sustainability has been a prime concern as a continued surging amount of construction and demolition waste (CDW) is being generated while natural resources are consumed and contaminated at an alarming rate. However, CDW utilization involves a range of options based on combinations of different crushing options and manufacture of various recycled products, which is confusing for practitioners to decide the optimal CDW utilization scheme from a comprehensive perspective. To assist decision making among CDW utilization schemes, a heterogeneous multi-criteria evaluation framework is proposed where interval numbers, triangular fuzzy numbers (TFNs) and trapezoidal fuzzy numbers (TrFNs) are used for comprehensive evaluation, enabling experts to present assessment information flexibly based on their preferences, knowledge and nature of different data forms. Firstly, a comprehensive index system is constructed from social, environmental, financial and technical dimensions for the evaluation of CDW utilization schemes. Afterwards, a novel method is proposed to unify heterogeneous evaluation values into rough numbers. Thirdly, to fully reflect both inner and outer dependencies among criteria, the analytic network process (ANP) method is utilized to derive weights of criteria and sub-criteria, before the fuzzy multi-attributive border approximation area comparison (MABAC) method is applied to obtain the final ranking. Finally, a case study of CDW utilization schemes selection problem is illustrated where the scheme of on-site crushing combined with production of recycled bricks and aggregates is selected as the best option with the sum of the distance S_k between alternatives and the border approximation areas obtained as [0.0037, 0.0544], and a comparative analysis is conducted to verify its effectiveness and validity of the proposed framework.