No abstract

The reverse logistics (RL) performance of construction and demolition waste (C&DW) differs significantly between countries. Although some countries are successfully circular, other countries are still far behind; with C&DW being largely directed to landfills or being illegally dumped. There is a lack of guidelines on the requirements for transitioning countries towards C&DW diversion, and little attention has been given to the factors that influence the success of C&DW RL and increased circularity. This study aims to develop a framework that helps in structuring and assessing the success of C&DW RL on a regional level and serves as a guide for transitioning developing countries towards implementing such operations. Since the framework should help evaluate where interventions are needed to enhance performance, the exact domains to be used and their priorities should be identified. A systematic literature review was conducted to identify the critical factors that affect the outcome of RL operations. After their identification, the interrelationships between the factors and the dependence and driving power of each are examined through interpretive structural modelling. This analysis provides valuable insights and thus, allows for the establishment of a hierarchy of factors that can serve as a guide for decisionmakers. The developed framework can be utilized for enhancing the efficiency of current RL operations as well as for identifying the direction of action and efforts needed to shift developing countries towards the implementation of circular economy in the sector of C&DW.

Little attention has been paid to the interaction or synergy among construction and demolition (C&D) waste management stakeholders. A framework allowing for interaction among the various C&D waste players is especially important in regions with mature C&D waste infrastructure, where various recycling, reuse and disposal facilities are present. In such an expanded infrastructure, these facilities differ in terms of the C&D waste materials they accept, the nature of the waste accepted (sorted/unsorted), as well as the services they provide. This makes developing the optimal C&D waste management plan (WMP) more cumbersome for contractors. To address the challenges arising from the poor dynamics associated with the overarching waste management infrastructure, this paper proposes a novel digital platform, namely the ‘Construction and Demolition Waste Management Kernel’ (C&D WMK). The C&D WMK has three main objectives: it allows for data exchange between the different stakeholders, provides guidance to contractors when developing C&D WMPs and allows for governmental supervision and regulation. This paper introduces the concept behind the C&D WMK, presents the optimization model embedded in the system, and demonstrates its application in a case study leveraging real-world data. Finally, a scenario analysis is conducted to show how the C&D WMK can be used by governments to identify pitfalls in the state of practice at the regional scale, and to determine effective solutions to enhance the C&D waste management performance.

No abstract

Illegal dumping of construction and demolition waste continues to be a problem hindering circular economy efforts. Controlling illegal dumping necessitates establishing an effective surveillance scheme and investigating the proper penalty value. This problem has previously been described as a game theory problem, with the government and construction contractors as the players. Taking into account illegal dumping hotspots, which can often be identified through topographical and geographical characteristics, is also important when establishing supervision strategies. This study develops an evolutionary game-theoretic model that can assist in devising effective supervision strategies to control the spread of illegal dumping, while taking into consideration hotspots. In specific, this study investigates the suitability of two alternative strategies: police patrols and hybrid monitoring through both patrols and the installation of closed-circuit television cameras in hotspots. The model was applied to two case studies, using parameters informed by real-world contexts, to demonstrate its potential for selecting suitable strategies according to local situations. The results suggest that nine possible scenarios govern the stable evolutionary strategies of game players, with five scenarios in which contractors converge to adopt legal dumping. Accordingly, based on the parameters of the region (hotspot areas, cost of supervision, efficiency of patrols, penalties, etc.), governments would be able to assess which of the strategies would lead to long-term compliance of contractors while also increasing their payoffs. Further analysis allowed to determine the minimum efficiency required, and simulations were performed to demonstrate the influence of different supervision efficiencies and penalties on the evolutionary strategies.