Companies (in general and in the dredging sector) are striving towards more sustainable operations. However, problems arise in the changing of current practices to operationalize sustainability goals in projects. The objective of this research is to describe the process of creating a sustainable operating environment for dredging and reclamation projects by analysing a dredging and reclamation project in the Maldives of Van Oord.

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.

Due to growing prosperity in the world, together with the trend of urbanization, more and more natural resources are needed. However, the earth cannot keep providing us these materials, since many of them are depleting. The concept of circular economy is seen as an opportunity to tackle this problem. However, the infrastructure industry lags behind in this transition. Transition theories state collaboration between stakeholders is the most important factor to transition successfully, and within the construction and infrastructure sector, partnering is seen as the ultimate form of collaboration. However, the role of partnering in the transition to a circular economy has never been studies before within the infrastructure sector. This research will try to fill in this knowledge gap by gaining empirical knowledge from the InnovA58, a highway alteration project in the Netherlands.
It was found there is a definite role of partnering on the transition to a circular economy within the infrastructure. Some elements of partnering contribute to the transition, others hamper it. Also, partnering triggers a motor of change in the transition, which acts as a flying wheel to accelerate the transition. Therefore, partnering plays a role in the circular economic transition both directly as well as indirectly.
Knowledge of the concept of partnering and the benefits it can bring can be highly positive for projects with a circular economic ambition, therefore, project team members as well as the client of such infrastructure projects should be knowledgeable about this topic. Furthermore, the current focus on the Iron Triangle in infrastructure projects is seen as a threat to the transition to a circular economy; something which will need to change radically, but can only be influenced slowly but steadily.

This report, which from now and onwards will be called the main body of the thesis, covers the core of the
problem that has to be solved. Generally, the aim of this thesis is to investigate a laminated composite’s
structural response, made of FRP, when its material properties are assumed stochastic instead of
deterministic. The materials shown in this thesis are investigated as part of a bigger project that concerns the
construction of several Mine Counter Measure Vessels.
In this document, the main focus is given on the results of experiments and/or analytical calculations whereas
the theories/methods used to extract these results are presented in the supporting document. As a result,
readers that are familiar with statistics, classical lamination theory, FEA modeling among others, can easily
read this report without coming across knowledge that they already have. In general, this document covers
the writer’s contribution to academics whereas the supporting document gives an extensive explanation on
what was used in this document.

The investment characteristics of wind parks have been analysed, the different risks to which a wind park investor requires compensation, the different models that can translate risk into returns, and finally the returns have been calculated with this model for different wind parks.

The construction sector is one of the biggest consumers of raw materials and generates large amounts of construction waste as well. CE is a way to delink the construction sector from the consumption of finite resources of the earth and excessive waste generation. Despite of the fact that there are a lot of interventions, such as Commodity agreement, Transition Agenda, it is not clear how CE can be executed in practice. This research aims to develop a guidance and a framework on the adoption of more circular innovative technologies in construction projects and to propose an approach that can support involved parties in order to realize more circular construction projects. This research adopts a unique approach in transitioning the construction sector to a CE using Service Dominant Logic (SDL). One of the key sources of non – adoption of CE is the lack of harmony or agreement on a suitable definition of CE for the construction sector. This may compromise the process of decision-making and eventually lead to ineffective policy interventions. Successfully implementing CE in the construction sector needs a definition that covers the whole construction supply chain to provide understanding of material flows in the economy.

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.

The monopile is the prevailing foundation concept applied in offshore wind farms, mainly due to construction of offshore wind farms in relatively shallow water. The monopile can provide a technically and financially feasible solution in shallow water environment due to its’ ability to support the wind generator ensuring at the same time the maximum production, since it can provide a foundation concept which ensures that the displacement and rotation thresholds set by the wind turbine manufacturers are being met. However, the trend nowadays is to develop wind farms in deeper water and to use wind turbines of higher capacity in order to increase the electricity production. This can be translated to a demand to increase the dimensions of the monopile, leading to complications in the transportation and installation procedures. This thesis project focuses on the possibility to enhance the structural and dynamic behavior of the monopile by filling it with sand. The effect of the sand-fill on the local buckling, on the static displacement, on the natural frequency and on the damping ratio of the structure have been investigated. In order to estimate the effect of sand-fill on local buckling, its’ effect on the ovalization of the monopile’s cross-section was estimated using the relevant European Standards and Dutch guidelines. The analysis has shown that for an increasing Youngs Modulus (E) of the sand-fill, the ovalization of the monopile at the critical cross-section decreases significantly, which in turn increases the bending resistance of the filled monopile. The effect of the sand-fill on the static displacement has been estimated by modeling the monopile in Plaxis 3D. The effect of sand-fill appears to be more significant for lower static loads. The effect of sand-fill on the fundamental natural frequency of the structure was estimated analytically by using the approximate normal modes obtained by the Euler Bernoulli beam equations and numerically, using the finite difference method to model the structure. The results of the analysis have shown that the total effect of the sand-fill on the natural frequency of the structure is negative, and sand-fill should be applied only in cases when a decrease of the natural frequency of an existing structure is required. The effect of sand-fill on the damping ratio of the structure has been performed through Free Vibration Tests which have been simulated in Plaxis 3D. The analysis has shown that the hysteretic behavior of the sand-fill leads to an increase of the damping ratio of the structure. The beneficial effect of the sand-fill on the damping ratio increases as the initial displacement applied at the top of the structure increases. Finally, a financial analysis was performed in order to identify the influence of sand-fill on the foundation cost. This additional cost sets the minimum threshold to be exceeded by the possible financial benefits achieved due to the higher damping ratio, in order that the sand-fill can be applied as a financially feasible solution.

The construction industry is a large generator of waste. The interest in improving the resource efficiency is growing. A move towards a Circular Economy (CE) has been assigned as the solution for a more efficient use of resources in the construction industry. The aim of a circular economy is to create a system in which waste and energy leakage is minimised and resource input is avoided by closing the material and energy loops. Despite the advantages of CE, the construction industry has not yet made a significant step towards
the CE. The theory of Reverse Logistics (RL) could be the enabler of circular economy in the construction industry. RL in the construction sector is defined as the management of collecting, sorting, processing and reusing construction waste. In the field of RL, quantitative models have proven to be a successful tool to combine environmental goals with financial constraints. However, such models are missing in the field of construction industry. In this context, this research proposed a general applicable RL-model that supports decision-makers in implementing circular principles in the return flow of their assets while minimising the costs.
Literature review has been conducted to obtain a theoretical framework for the model design. The first part of the literature study has provided a framework to prioritise different waste management strategies based on their level of circularity. The second part of the literature study has been conducted to get an insight in the characteristics of the reverse logistics in the infrastructure and how the principles of circular economy can be included in the RL-process.
The most suitable modelling approach for the proposed problem has been found to be linear programming.
The proposed RL-model has been designed as a transhipment model and is based on mixed integer linear programming (MILP). The proposed model design simulates the reverse flow of one asset moving from a deconstruction project, through the processing facilities to the final redistribution. The proposed model has been complemented by a guideline that supports the application of the model for specific cases.
To test the applicability of the model and the proposed guideline, the model has been applied on two different types of assets in the infrastructure: concrete and street lights.
The model for both cases have been run for multiple scenarios, based on the developments in the industry. The results of the model provides two types of information. Firstly, it provides a trade-off between the level of circularity and the costs. Secondly, it gives the corresponding network-design for the different outcomes. It was found that technical innovations in combination with efficient transportation will help to create return flow in the infrastructure, according to the principles of circular economy, which is financially feasible.
Overall the model has been proven to be general applicable and it supports decision-makers in making decisions about the reverse flow. The outcome gives information about the financial impact on implementing circular principles. The corresponding RL-network provides an insight in which aspects in the RL-process influences the outcome.

Professionals in the Operations and Maintenance phase of national road
infrastructure projects are making decisions with large consequences based on low frequency measurements and subjectivity prone expert observations. A solution is expected in sensor innovations, IoT and User Generated Data to generate more frequent measurements and less subjective observations. The use of these methods has been researched and proven, however the main focus of these studies was often improvement of the technological capabilities or implementation in current practises with limited research into their contribution and effects on professionals in the construction sector. This research describes an experiment that tested the effects of more data and more diverse data on the decision-making of professionals in the construction industry. An attempt to answer this question is made by modelling different data sources into a Serious Game and testing the assumptions. After analysis of the gaming data, the questionnaires and the debriefing it can be concluded that in this experiment there was a correlation between better assessments and higher scores. However experts did not assess damage differently when presented with extra information, nor did they make significantly different decisions. From the qualitative section of the experiment the explanation was found that the extra information proved too much and experts were able to extrapolate with the marginal data that represents the current industry practise. This suggests that new information requires training, as our built environment gets richer in terms of data, the assessment of this built environment becomes too much for humans to cope with and solutions can be sought in the application smart algorithms, Machine Learning and Artificial Intelligence.

The current practice of bridge maintenance decision-making is informed by subjective visual inspection data with a long time interval between measurements, which creates inefficiencies and possible loss of value in the maintenance entity’s capabilities. New opportunities from technology-related innovations for measurement devices are available for better-informed decision-making and for improved knowledge on the condition of a bridge. Even though, the adoption and use of these opportunities seems to be disregarded by the market and the main focus of innovation pushing organisations is mostly on the technical capabilities of these systems. This research presents a study on the effects of using technology-related opportunities on maintenance decision-making from a usercentric perspective. It performed a serious gaming experiment where bridge maintenance decision-making professionals were questioned to set up maintenance advices based on different types of data. No previous similar research was found through extensive literature search. Bridge deterioration scenarios were presented to experts throughout a within-subject fractional factorial experiment design. The experiment treatment groups consisted of data presentation from new innovative or potential bridge condition assessment mechanisms and the experiment control group consisted of the current data source, which is visual inspection. To observe the effects, the experiment used a quantitative and qualitative approach that considered expert judgement, maintenance decisions, and explanations of the experts for observing whether differences occurred between the different settings. It was indicated that significant differences were present if new data sources were added to the current visual inspection data, but no significant differences were observed between different types of data sources. It is expected that the differences are caused by the ability to observe quantified values of important performance indicators better, and that they provided indicative values that can be used during decision-making. It is expected that the latter described indifferences were caused by a lack of guidance by the market on how to use new data sources properly and consistently. These outcomes mean that for efficient and effective adoption of new data sources, more standards and guidelines about threshold values and causal links between deterioration parameters and possible deterioration causes are needed for practical guidance during maintenance decision-making. It suggests that in order to provide a broad facilitation for adoption of new data sources, long-term strategy behaviour must be considered by the market in order to provide a safe space for pilots and trials to learn about these innovations.

In the current era of cut-throat competition, companies carry out projects to support its business. However, studies show that these projects fail to provide the expected results. This is due to the fast-changing environment where the project is set-in. The planning of the projects is influenced by the presence of these uncertainties and hence, they need to be managed for successful project completion. In this research, a model is proposed for project planning under uncertainties. The study was conducted in a high-tech company, which designs and manufactures state-of-the-art machines. In order to develop the model, an extensive literature review was conducted on project planning and also on the impact of project uncertainties on project planning. Following this, interviews were conducted within the company to understand the current practice of project planning within the organization. A total of five major issues with planning were identified. These were: scope changes, project delays, lack of governance, complexity and project escalations. A model was developed to tackle these issues with project planning. Schedule risk analysis was proposed into the way of working of the organization in order to minimize/ mitigate the occurrence of project uncertainties while planning.