Growing depletion of natural resources and ever-intensifying pollution of the environment has heightened the awareness for changes in our life and living. As an alternative to the traditional take-make-use-dispose production model, Circular Economy (CE), which focuses on recovering and regenerating products and materials, has been gathering interest. In particular, its application to the construction industry, which is responsible for a high percentage of global carbon emissions and resource consumption, is of both need and significance.

In Taiwan, the construction industry has been highlighted for the government-initiated CE transition. However, as elsewhere in the world, the construction industry has been slow in embracing circular principles and strategies. Among the challenges is the lack of an assessment metrics for gauging CE performance. Existing schemes for assessing building circularity are few. In 2018, the Building Research Establishment Environmental Assessment Method (BREEAM) from the United Kingdom proposed a framework of circular indicators (BREEAM-C) on the basis of its original green building certification scheme (BREEAM-G).

This thesis is an in-depth analysis of BREEAM-C on its applicability and potential for adoption in Taiwan to assess building circularity and to promote circular construction. Methods applied include literature review, cross-case analysis and collecting expert opinions using semi-structured interviews.

The analysis involves scrutinising whether the indicators are rooted in CE principles, are realizable through circular strategies, cover well different impact areas, structural layers and life-cycle stages of buildings, and can recognise circular building practices implemented. The applicability of BREEAM-C in real-life contexts is further examined using two circular building projects, Venlo City Hall of the Netherlands and TaiSugar’s Circular Village of Taiwan. The cross-case analysis also serves to identify BREEAM-C’s strengths, inadequacies as well as room for improvement.

Results showed that BREEAM-C is applicable, practical and can be adopted for building circularity assessment in Taiwan though not without adaptation or localisation considering different concerns with respect to climate and safety. Green building rating schemes, which have been widely adopted in the past decades offer an excellent platform for developing equivalent assessment schemes for circular buildings. In particular, for practitioners and stakeholders in Taiwan, using its own green building certification system, Ecology, Energy saving, Waste reduction and Health, as the basis would make new building circularity assessment scheme to be introduced, accepted and followed easier, which in turn would facilitate the promotion of circular construction.

In recent decades Europe has been increasing its demand and consumption of electronics. This has in turn resulted in major outflows of waste electronics (WEEE) that are usually not properly dealt with. This is especially the case for low to medium grade printed circuit boards (PCBs) which unlike higher grade electronics such as computers are currently not profitable to recycle. Therefore this thesis, as a part of the Peacoc project, investigated the low energy separation methods roll sorting, magnetic separation and magnetic density separation to concentrate the precious and critical metals found in the components of these discarded PCBs. The resulting secondary material flows were then evaluated on their impact in the EU from a material and energetical perspective.The roll sorter was able to significantly increase the concentrations of the precious metal rich target components (Central processing units, IC chips and transistors, MLCC + Ta capacitors, Small transistors and IC chips and Connectors of plastic with golden pins). The machine sorted the feed into multiple width sizes (< 3.0, 3.0 - 5.0, 5.0 - 7.0 and > 7.0 mm) of which all except > 7.0 were used for further processing, increasing the overall grade from 18.66 to 42.61 wt%. This was further increased by the magnetic separator (lightly and non magnetic fractions for < 3.0 mm and only the non magnetic fraction for 3.0 - 7.0 mm) to 53.69 wt% and magnetic density separation (only for non magnetic 5.0 - 7.0 mm)to 66.23 wt%. Recovery for all target categories was near 100% with the exception of Connectors of plastic with golden pins as these were too large for the roll sorter to sort.The thesis also took a broader approach by employing a dynamic material flow analysis to determine the low to medium grade PCBs and their accompanying precious metal flows in the EU. The expected metal flows were low (∼4%) compared to the EU’s overall demand in 2020 and expected to decrease over the years due to miniaturisation (decreasing size and weight) of the components. Furthermore, only around 36.68 wt% of the maximum precious metal flows were expected to be captured due to low collection rates of WEEE and small loses in separation and metallurgical recovery. Nonetheless, a sizeable fraction of the EU’s electronics sector’s demand (over 10%) could be supplied. These results were confirmed by modelling different future scenarios, a Monte-Carlo uncertainty and sensitivity analysis of the model.Lastly, the thesis explored the topic of critical raw materials (CRMs) and the direct energy requirements of Peacoc’s recovery system. It was found that beryllium, antimony, platinum and palladium were the only CRMs that had any significant potential to supply the EU (9.13% for beryllium, 1.58% for antimony,1.32% for platinum and 4.02% for palladium). If only looking at the electronics sector this was also the case for cobalt and vanadium. The newly captured secondary precious metals were shown to require significantly less energy to produce, around an order of magnitude, compared to primary production but were similar to other recycling pathways. Furthermore, the majority of energy was required during metallurgical recovery showing a potential for further mechanical concentration during separation.In conclusion it can be stated that the separation technologies (roll sorting, magnetic separation and magnetic density separation) are effective methods for separating the components of low to medium grade PCBs. However, their impact on the circularity and energetical footprint of the whole EU are expected to be small.

The main motivation for this research originated from two ambitions, which involve many challenges for which circular solutions have to be developed. First, the ambition of the Dutch government to achieve a circular economy, which also includes a circular construction industry, in the Netherlands by 2050 at the latest. Secondly, in line with the first, the ambition of Rijkswaterstaat to work climate-neutral and circular in 2030. At this moment, the main focus in the Dutch construction industry is on developing circular solutions which can be implemented and applied during the enormous replacement and renovation task of many of the almost 40.000 bridges and (mostly) viaducts in the Netherlands. Therefore, the main focus of this research has been on developing circular solutions for concrete viaducts for (governmental) roads. This has resulted in the development of a concept demountable footing to foundation (F2F) dowel connection which has been based on, and is suitable for application in, the proposed design of a standard (circular concrete) viaduct. Besides, attention has been paid to desired monitoring aspects regarding such a circular viaduct, and to the life-cycle costs of a circular viaduct compared to those of the same viaduct, constructed in a traditional way, characterized by a linear life-cycle model.

In the recent years, the circular economy (CE) has emerged as an alternative to current linear economic models with prospects of achieving the decoupling of environmental impacts from economic growth. To this end, CE models focus on the permanence of products, materials, and value in the economy, eliminating as much waste as possible. In waste management policy making, traditional indicators, such as recycling rates, are still the norm as demonstrated by the latest binding goals for plastic packaging recycling set by the EU in the Packaging Waste or the Single Use Plastics Directives. However, these have been criticized for overlooking qualitative aspects that are fundamental in the CE. Consequently, several indicators have been proposed as an alternative to monitor this new economic paradigm. Among these are value-based metrics. Economic value contains information about both the quality and the quantity of the specific material or product. In addition, value can be altered using economic instruments, such as taxes, to align value with other relevant environmental or social interests.
The validity of using value-based metrics to evaluate the performance of waste management systems was analysed. Several scenarios for possible configurations of the Dutch post-consumer plastic packaging waste (PCPPW) management network were defined and assessed in terms of technical, economic, and environmental performance. Two technical metrics, intermediate recycling rates (iRR) and recycling rates (RR), and one value-based metric, the circular economy index (CEI), were compared to the environmental and economic performance of the scenarios. The CEI showed a better alignment with all the environmental impact categories than the mass-based metrics. Most importantly, the value-based metric proved capable of capturing the significance of the quality of the recycled plastics in the displacement of primary raw materials, thus fostering high quality recycling over downcycling. However, no correlation was found between the economic performance and the presented indicators. There are multiple business models that achieve good economic performances with diverse environmental, technical, or value-recovery performances. This suggests that current policies are unable to successfully align economic and environmental strategies. More research should be put in defining holistic policies that promote environmental and economically sustainable practices.

The use of concrete, the world’s most applied construction material, has significant environmental impact in its sourcing and end-of-life stages. Closing the concrete loop prevents devalorization of concrete (aggregates) and has environmental benefits. In the European Union, the recently published Green Deal provides additional stimulus to the circular economy ambitions of its member states. In the Netherlands, information systems that store data on material stocks and flows, known as material passport systems, are considered vital in the transition to a circular (construction) economy. However, the digital representation of our physical world is only as good as the translation into digital data. Radio Frequency IDentification (RFID) technology bridges the gap between the digital and physical world. Therefore, this thesis assesses the opportunities and challenges of a proposed RFID-based Integrated Material Passport System (IMPS) for concrete (aggregates) in the Netherlands. The development and diffusion of this innovation were analyzed using Geels’ Multi-Level Perspective framework. A mixed-methods approach was applied to assess the Dutch concrete chain’s perception of such a system, and test the performance of an RFID material passport for concrete on a lab scale. The ambition and need to develop information systems for a circular economy is shared by the public and private sector; the majority of respondents (79%) think it is important to receive more information from the concrete chain, especially information regarding the concrete’s composition, and environmental performance. Moreover, 85% of the respondents were interested in an information system for concrete that provides them with this information. However, the intra-sectoral information infrastructure is currently insufficient for the required digital communications. Although the RFID-based system tested in this thesis showed opportunities for real-world applications, its performance is currently insufficient in terms of resistance to external forces. The development of RFID technology and an IMPS requires changes in economic incentives, policy, and technological performance. The development and communication of knowledge are considered the most crucial factors for developing and diffusing the IMPS in the Netherlands. Developments should focus on gathering lead users, research institutes, and investors, in a ‘coalition of the willing,’ for experimentation with decentralized information systems, and RFID technology. Regarding the MPS, a sector-wide approach for the normalization, sharing, and security of information is required. The focus of the approach should be on information logistics and access, rather than information registration. However, for the transition from the EoL to the sourcing phase, additional objective quality information registration is required. Although new technological innovations allow us to close the concrete loop further, the majority of secondary materials exits the cycle to road construction activities. While it has value as a road-base, the application of secondary concrete currently prohibits its re-introduction into the concrete chain. The current demand for concrete outweighs all secondary concrete supply. Taking the national infrastructure budget into account, construction activities will increase in the next five years, meaning the Netherlands will require additional virgin concrete resources in the coming years. These background activities provide opportunities and urgency for the development of innovative methods for the transition to a circular concrete chain and a circular economy.

In 2017, the Dutch government has set the goal to achieve a 100% circular economy by 2050. A transition from the current linear economy towards a circular economy is necessary to reach this goal. In the circular economy, products at end-of-life are no longer seen as waste but will be reused as a secondary product or resource.

The general aim of this research is to investigate the implementation of the circular economy concept in the public space. From this study, it became clear that Dutch municipalities are willing to implement circularity for assets released from the public space. However, the municipalities are not aware of the actions which are required to increase the circularity within its maintenance activities. A method is proposed which gives decision makers of a municipality guidelines to justify their decision for a maintenance plan of an urban area. This method includes PAVE (maintenance plan analysis tool to value enhancement of circularity in the public space): a tool which quantifies the environmental and economic impact of maintenance plans. To express the impacts four criteria were selected: the carbon footprint, financial footprint, material loss and monetary value loss. The tool follows a life cycle assessment (LCA) framework.

In this research, the use of PAVE was investigated during the maintenance of a neighbourhood in Almere. It was concluded that to be able to implement PAVE in an effective manner, the asset database of the municipality needs to be updated to fill in the information gap. Part of the case area database was renewed to conduct an inventory of the assets in the selected urban area for this research. In PAVE, the impacts of the selected assets were calculated for both the circular project plan of the contractor and the traditional linear plan. PAVE indicated that using the new project plan for the case area results in approximately 1455 ton less CO2 emissions and is €4304000 cheaper compared to the traditional linear maintenance plan. Furthermore, PAVE demonstrated that the use of the new plan leads to 238 m3 and €424.000 less material and monetary value loss, respectively.

In this research, it was evident that to select a maintenance plan among others, the tool should be included in the decision-making scheme of municipalities. By implementing PAVE, decision makers will be able to compare the impacts of different maintenance plans and select the most suitable plan based on environmental and economic considerations. The implementation of the tool can be ensured by making the provided budget dependent on implementation. Finally, the proposed plans of contractors should be evaluated on their circularity. Guidelines have been formulated to support the selection of the maintenance plan for urban areas in the public space.

The demolition activities produce a huge amount of waste that have negative effects on the environment. In the current demolition practices, most of the waste are recycled or landfilled. Only a small percentage is retrieved and reused again. Reuse is preferred than recycling since it better for the environment. To increase the reuse, more materials need to become available from the demolition activities. To current demolition process does not enable the retrieval of components and materials for reuse since they are damaged in the process, and the demolition contractors don’t make an effort to retrieve them properly. This thesis investigated the demolition process and how its steps and the actors involved could affect the reuse potential of components and materials in the building industry. To find answers, literature study, a case study and expert interviews with frontrunners were used. The best practices from the Netherlands were taken as an input in order to develop the new process. Based on the findings, a flowchart of the new demolition process is developed, and recommendations are given to the actors involved. Changes are proposed in the five stages (tender, audit, planning, execution, materials handling) of the demolition process and to the actors involved. Sustainability tender criteria, site visits, detailed inventory, buyers through the network, deconstruction, separation in different material streams are some of the changes that need to be made. By adopting the proposed changes the actors involved could retrieve a lot more components and material from the demolition sites and provide them for reuse.