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.

Recycled aggregate concrete is emphasized more and more nowadays due to its importance towards the construction industry and general welfare of our planet. Being such a significant feature with regard to universal sustainable development, every aspect of its properties should be evaluated, examined and optimized so that there is a well-known, well-described and ready to use product. This project aimed at correlating some of the established parameters of conventional concrete such as water absorption of the coarse aggregate fraction and the resulting compressing strength, only applied in the field of recycled aggregate concrete. Along with these two properties, a prediction model was sought for which would be able to forecast the mechanical strength of concrete based on its coarse aggregate composition. A series of experiments were performed on samples fabricated for water absorption tests and compressive strength assessment. In total, 112 water absorption samples and over 250 concrete specimens were prepared and examined for the respective attribute. These samples used natural aggregate as the base of the coarse aggregate portion of the mix design, alongside a series of so-called contaminants which replaced the gravel in certain concentrations. These contaminants included bricks, ceramic tiles, glass, wood, gypsum, plastics, mineral fibers and recycled sand concrete and were entirely based upon the C&DW composition globally. Further investigation was done on the inclusion of air within concrete so that contaminated concrete results could be equated to this constant. All water absorption tests were performed according to the current standards and concrete specimens were crushed after 7 and 28 days of curing in order to obtain their strength in compression, while the predictive model was initiated via the Minitab statistical software. The results indicated some interesting and promising trends. From both sets of experiments, it was evident that the water absorption of the coarse aggregate fraction was not the main contributor towards the strength development of recycled concrete. It had a minor influence, especially compared to the type of contaminant present and how much volume it took. Furthermore, samples with identical water absorption fabricated concretes with different strengths. Overall, plastics and wood had the most negative effect in terms of compressive strength, while bricks, tiles and glass seemed to affect this aspect in neutral or even slightly positive manner. EPS foam in very limited amounts yielded a notable 30 to 35% strength drop, while on the other hand, brick replacing 20% of the NA improved the strength by approximately 7% after 7 days and 2% after 28 days. In the end, based on all experimental input, a predictive model was developed, optimized and validated in several steps so that it was able to predict the water absorption of coarse aggregate, compressive strength after 7 and 28 days and equivalent air content based on the composition of the coarse aggregates. The back-end of the model is provided within the report as a MATLAB code.

Current linear economic model entails coupling of economic growth with resource constraints and degradation of the Earth. In order to combat these negative aspects and to ensure prosperous and sustainable future, a new economic approach is emerging - Circular Economy. Besides neutralizing threats of the linear model, it also promises additional financial, societal and environmental benefits. This is recognized on (inter)national level with numerous action plans and legislation. However there are almost no actions that are aiming at implementing the notion of circular economy on the level of supply chains/ Therefore, inertia is observed in supply chains in relation to changing towards circularity. This thesis looks at the underlying reasons for this with the research methodology designed around the Social Network Analysis approach. Two main reasons for inertia in supply chains stemmed out of research: differences in perceptions of the actors within a supply chain and diffusion of responsibility phenomenon. Going one level deeper, four causes for these developments were uncovered: 1. Lack of incentives for companies in supply chains for making a change towards Circular Economy. 2. High uncertainties and risks that a change to circularity implies for companies in supply chains. 3. Lack of mutual interests between actors in supply chains for making a change towards circularity 4. Clashes of perceptions on all levels in supply chains, as well as between supply chains and government.

Building construction is a material-intensive process known for depleting natural resources, mainly gravel and sand, used in concrete production. At the same time, building demolition generates large amounts of construction and demolition waste (CDW), primarily consisting of end-of-life (EOL) concrete, a significant waste flow occurring in Europe's construction sector. The potential to deal with waste management and the uprising demand for new concrete in construction lies within circular economy-based solutions applied throughout the building's lifecycle. Steering in this direction, the European Union is endorsing a circular economy strategy that aims to utilize EOL concrete derived from CDW to produce new concrete and thus minimize virgin material inputs. These efforts have not been translated to a uniform framework for Europe, where practices, regulations for waste management, and market acceptance for secondary raw materials differ among member countries. In this project, different types of pre-demolition audits, demolition, and waste processing methods for EOL concrete are compared, showcasing the status quo across the EU and the Dutch case study, which portrays innovations that can shape the future of concrete recycling. An integrated LCA and LCC framework is applied from the demolition stage to waste processing and the production of materials for new construction to capture potential environmental and economic benefits and drawbacks at the end-of-life stage (EOL) of the building. The results showcase the pivotal role of BIM-supported pre-demolition audits in combination with selective demolition with benefits that include lower quantity of generated waste allocated to treatment and more components available for reuse. Finally, LIBS, a quality assurance tool for recycled aggregates, shows great potential in supporting a market for secondary raw materials in Europe.

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 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 aim of this research was to investigate the effects of implementing circularity in infrastructural construction projects. As a very polluting sector, circularity is becoming a more and more popular theme in the construction industry. Driven by both governmental regulations of reaching a full circular economy in 2050 and intrinsic motivation, construction companies are slowly introducing practices which contribute to circularity. Unfortunately, not much is yet known about the effects on project process and construction costs when implementing circularity. This research has initiated the first step towards understanding what the effects of circularity are on infrastructural construction projects, providing welcoming insights to both the academic world and practice. Based on a case specific comparison, a circular construction project is more expensive than a regular construction project, due to extra activities which need to be executed before a secondhand material can be applied. Regarding the project process, the circular construction project introduced ''gathering of materials'' as a whole new process step which is constantly interchanging with (re)design until a final design has been completed.

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 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 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 European construction sector is responsible for the consumption of almost 32% of total raw material for realizing its projects (Benachio, Freitas, & Tavares , 2020). On a national level, this amount results to almost 50% for the Dutch construction industry (Nellssen, et al., 2018). The ever-growing population stresses the need for sufficient infrastructure and services which only results in an increase in demand and eventually an increase in resource consumption. The current trend of linear model, wherein the virgin raw materials are used to construct end products and eventually discarded at its end of life, poses a major threat for raw material extinction, and adds to the problem of excessive resource consumption. A viable solution for this problem is the introduction of circular economy concepts that aim at closing the raw material loops by considering all the current and future life cycle phases of a product in the initial development stages. Since the launch of the Ellen MacArthur Foundation (EMF) in 2010, circular economy (CE) has gained considerable attention. EMF defines circular economy as “a regenerative system that aims to keep materials in a closed loop at their highest value” (Foundation, Cities in the circular economy: An initial exploration , 2017, page 7). CE focuses on much more than reduction of waste through recycling and aims at reducing the consumption of raw materials, designing products such that they can easily be disassembled and reused and extending product lifespan through maintenance and repair. CE differentiates the gradation options that help keep the materials and components within the loop by options such as refuse, reduce, reuse, repair, etc. One of the important parts of any city is its transport infrastructure that can also make use of the circularity principle. For many developed and developing countries, transport infrastructure accounts for the largest proportion of a country’s budget of any public-works program and consequently also play an important part in a nation’s economic and regional development. Studies show that current developing research of circular economy seldom focuses on the assessment of such transport infrastructure. Therefore, the main focus of this study is to understand the barriers of circular economy and to develop an assessment framework that can help the evaluation of transport infrastructure in terms of circularity.