Construction and demolition waste framework of circular economy: A mini review

The hidden concept and the beauty of multiple "R" in the framework of waste strategies development reflecting to circular economy principles

There are numerous unresolved research questions, along with ongoing debates, regarding how to achieve a circular economy and at what level. The forthcoming circular economy standard (ISO 59000 framework, ISO59010) as a result from the ISO/TC 323, from the International Organization for Standardization (ISO) aims to offer global implementation pathways using a unified technical language. The most challenging aspect of circularity, whether viewed scientifically, technically, and/or legislatively, is how to enhance prosperity while reducing reliance on primary materials and energy to achieve climate neutrality by 2050, thereby aiding the EU in achieving a successful and equitable transition towards a sustainable future. Strategies in the framework of waste management and circular economy are essential and needed to reduce the impact of several processes on the environment through product, processes, and corporate policies using green applicable sustainable resources and environmental management systems. In addition, "measuring something that is not there" is very complex and not fully comprehensible, not clear and not tangible from organizations, researchers, policy makers and citizens. The willingness and ability of individuals or organizations to take actions towards a low-carbon society involves grappling with various perspectives, such as social norms and economic viability. Circular economy is considered a tool in combating climate change and implementing climate mitigation (as well as adaptation) measures. Moreover, to date, there has been no common scientific or technical language for the application of the circular economy concept. This paper highlights the multitude of "Rs" beyond the well-known (3Rs) Reduce-Reuse-Recycle pattern, which can be applied in various contexts to assist SMEs (Small and Medium Enterprises), organizations and even citizens successfully adopt circular economy principles. Is also explores how these "Rs" can be utilized to measure intangible aspects (something that is not there). The results indicate that more than 55Rs exist which directly involved in the circular economy framework, also considering waste management strategies. The findings of this study reveal the existence of over 100 "Rs" beyond the well-known principles of "reduce, reuse, recycle," each playing a distinct role in the development of strategies aimed at addressing waste management issues and advancing circularity towards a low-carbon society. Furthermore, the results could be useful for any policy makers, consultants, engineers, practitioners, urban planners, academics etc., in order to develop, apply, monitor, measure and improve any strategy such as circular economy strategy, waste prevention, zero waste, reuse, reduce, energy recovery etc., in the framework of circular economy principles, solid waste management and beyond.

The effect of incentive policies on the diffusion of construction and demolition waste recycling: A government perspective

Construction and demolition (C&D) waste recycling plays a significant role in waste reduction and carbon reduction, which is critical for sustainable development. However, due to various limitations such as financial problems, C&D waste recycling industry is not well developed in developing countries. To address this problem, this study combines complex network theory and evolutionary game theory to analyse the diffusion of C&D waste recycling behaviour among enterprises under governmental incentive policies within a complex network context. The results demonstrate that the size of the network has limited effects on behaviour diffusion in Watts-Strogatz small-world network. Additionally, the study highlights the clear impact of governmental incentive probability, initial rate and connection degree on the diffusion path. By quantitatively investigating the effects of incentive tools, this study contributes to the knowledge of C&D waste management and provides valuable implications for stakeholders seeking to promote the diffusion of C&D waste recycling.

Thermoactivated cement from construction and demolition waste for pavement base stabilization: A case study in Brazil

Construction and demolition waste (CDW) worldwide generation accounts 10 billion tonnes yearly. The major fraction is landfilled requiring innovative recycling methods to reduce the associated environmental impacts and to increase its circularity. Our study demonstrated the feasibility of using different CDW fines to develop recycled cements and optimized the content of CDW recycled cements with well-graded crushed stone (WGCS) for use as pavement base layer. We scaled up the study obtaining CDW cement and aggregates from a local recycling plant, as well as pilot pavement sections designed, constructed and field deflections measured. As results, the CDW cement pastes exhibited accumulated heat values of up to 111 J g-1 and achieved a compressive strength of approximately 16 MPa. The unconfined compressive strength and resilient modulus (RM) achieved using CDW cement and WGCS were 2-3 and >3000 MPa, respectively. The sections constructed using CDW cement exhibited intermediate behaviour compared to those obtained using reference materials (6% Portland cement-WGCS and a conventional granular base made using WGCS). The deflection decreased over time owing to the pozzolanic reaction.

Circular economy strategies for waste management in Sri Lanka: A focus on demolitions and repurpose and material recovery and production stages

In Sri Lanka, the management of Construction & Demolition (C&D) waste poses a major problem, leading to environmental degradation and depletion of resources. This study aims to tackle these issues by examining the implementation of Circular Economy (CE) strategies within the construction industry of Sri Lanka. The focus is on reducing waste generation and maximizing resource utilization during the demolitions and repurpose, as well as material recovery and production stages of the building project life cycle. These stages are crucial in terms of waste generation and resource consumption. A qualitative approach was employed in this research, utilizing the Delphi technique to gather insights through a series of three rounds of expert interviews. In the first round, 17 experts were involved, followed by 15 in the second round, and 12 in the final round. The data collected from these interviews were analysed using manual content analysis methods. Based on the research findings, a total of 14 C&D Waste Management (WM) issues were identified specifically in the Demolitions and Repurpose Stage in Sri Lanka. For each issue, suitable strategies were proposed to overcome them effectively. Furthermore, the study examined the impact of CE strategies on minimizing these issues within the context of the project management iron triangle. Similarly, the Material Recovery and Production Stage of the building presented eight C&D WM issues, each accompanied by corresponding strategies to address them. The research also explored the influence of CE strategies in mitigating these issues, considering the project management iron triangle. During the demolitions and repurpose stage, CE strategies focus on reducing waste generation and optimizing resource utilization. This involves carefully deconstructing buildings to salvage and recover materials that can be reused or repurposed.