Over the last years the critical state of existing quay wall structures have gained a lot of concern. With the focus on urban quay walls in Amsterdam, a lot of aspects could play a role which limit the possibilities for both the design and the construction. The focus in this research is placed at the structural efficiency of the design for renovation projects. By using a parametric approach (with Grasshopper/Rhino) in the preliminary design phase, a design solution with the lowest use of material can be found.

From the total of embankment within the management of the municipality, a scope has been defined focusing on the most critical quays with respect to the limited design space and high expected loads. Within the assumptions made, the developed parametric tool can be used to indicate an efficient design solution for which the positioning of the piles, the diameter of the piles and the thickness of the floor follow from the location-dependent input. The indication of the effect of geometrical properties with respect to the defined objective (minimizing the material use) could help in the consideration of the design requirements.

Apart from indicating the savings that can be made on the material use by improving the structural efficiency of urban quay wall design, this research also contributes to proof of the power to be found in a parametric approach. The repetitive character in especially large-scale assignments as the renovation of Amsterdam's quay walls makes it a highly appropriate method.

This thesis report provides an analysis of the structural behavior of façades made of CLT panels with openings. These openings will have a significant influence on the transfer of forces in the panels, as well as the stiffness of the façade. The connections required to transfer the forces between the panels are designed. Deformations of the connections introduce addition deformation of the façade itself. The components that influence the force transfer and deformation of the façade have been identified in this research. Their contributions have been investigated. The theoretical calculations have been compared to computer results. The resulting conclusions aid designers in an early design phase regarding the feasibility of a CLT façade structure.

The main focus of the research has been on the mechanical fastener connections that are required for the CLT façades. The research question is stated as:

“What is the influence of mechanical fastener connections on the strength and stiffness of CLT façades that function as the main stability system?”

The research started with the goal to find the limitations of CLT façades for multi-story timber buildings. In order to find these limitations, a complete understanding of the structural behavior of the façade was required. Since connections were found to be of great influence the research focused on this topic.

The structural behavior of the façade was defined as the top deformation of the structure and the force transfer and resulting stresses in the panels. The dynamic response of the structure has not been analyzed.
Seven components were identified that influence the stiffness and force transfer in the structure.

Bending of the façade
Shearing of the façade
Bending of lintels
Bending of piers
Sliding of connections
Rocking of connections
Additional bending deformations due to connections

Computer models were used to verify the overall behavior of the façade as found with the theory. The computer model did not verify each individual component.

Peak shear forces in the CLT panels near the corners of openings determine the required panel thickness.
When these shear forces are reduced (for example by applying a concrete core in the structure) the required panel thickness can be reduced.

Top deformations of a façade with a width of 20 meter limit the maximum height to 45 to 55 meter, depending on the connection stiffness.

The main contributor to the top deformation is the connection stiffness of the connections between the vertical edges of the CLT panels. These influence the collaboration between the panels, hence significantly affect the bending stiffness and corresponding bending forces in the panels.

The lintels of the façade panels highly influence the load distribution in the façade. There is no accurate method to calculate this influence on the load distribution.

Wind turbines are decommissioned when they reach their endoflife. The reason for reaching endoflife varies per wind turbine, but they all have in common that the wind turbine blades can not be recycled and thus end up as waste. Since a growing amount of wind turbines will reach their endoflife the coming decade, the waste problem will increase. To solve or limit this problem, the lifetime of a blade can be extended, or a sustainable endoflife treatment can be established. This is currently not available yet. This research focuses on repurposing wind turbine blades. The objective is not to find one application, but rather to propose a method that enables large scale processing of wind turbine blades, for applications in the construction industry. Since to date it is uncommon to repurpose wind turbine blades, Two processes are proposed to give guidance on how to repurpose wind turbine blades. The first process is meant to repurpose as many blades as possible, by sawing the blade in plates and beams that can be applied to construction projects. The second process gives guidance to a project team that wants to incorporate wind turbine blades in their construction project, which can raise awareness for the waste problem. Both processess are supported by a grasshopper script. This script enables the user to either find an efficient mapping of elements that can be extracted from the blade, or gives design freedom depending on the aim of the repurpose project. The first process is further worked out. A geometry model of an actual wind turbine blade is analyzed and categorized in panels with a homogeneous material layup. On this panels, a nesting pattern of plates and beams, as commonly used in the construction industry, is projected which can later be sawn into relative flat plates and beams. With this, almost half of the blade panels can be turned into useful construction elements. The cross section of a blade consists of various functions, and thus various material structures. Three categories are distinguished: Spar caps, shell panels and the shear web. For each of these categories, the material layup and properties are analysed, which has led to an advice on possible applications. Spar caps are strong, stiff and have a homogeneous cross section. They can be repurposed as structural beams. Shell panels are light and stiff and can be repurposed as partition walls, formwork or flooring. The shear web is light, stiff, and entails good insulation properties. This can be repurposed as building cladding. Although this research does not contain sample tests, the material properties of the blade are provided and are of significant value, despite their 27 years of service.

Very little research has been done on the potential use of glass bottles in a structural system. Knowledge gathered from past projects showed that individuals or communities usually tend to create structures with glass bottles with a cementitious material, which is usually concrete or mortar. Under vertical compressive loading, the corresponding failure mechanisms should predominately be fractures in either the heel or the shoulder. Using two different finite element models and Weibull Analysis, a characteristic tensile strength of abraded container glass of 20 MPa was found. When structures are created out of glass waste, designs should be made with the abraded state in mind.

Connections concepts are created to connect glass bottles together, i.e. 'Masonry', 'Stacked' and 'Bundled'. The 'Stacked' concept was considered the most suitable for this thesis. Eight different configurations of the Stacked concept were created, of which four were tested in a hydraulic displacement controlled compression machine in Stevinlab. These four configurations were called 'Whole-Up', 'Whole-FF', 'Whole-BB' and 'Cut-Double-BB'. The results showed that the Whole-Up had the highest vertical failure loads, followed by the Whole-FF and Whole-BB configurations, and the Cut-Double-BB have much lower failure loads, which is most likely due to the imperfections at the cut surface.

Following these results, two different design options were created. The final prototype contains a demountable glass bottle column with intermediate plates and plastic elements. A proposed design formula for the vertical compressive design load was created based upon collected data and safety factors. The limitations of the bottle column are mainly the tolerance issues due to the different bottle heights and connections, the costs of the connections and the capacity in comparison with more conventional materials. The bottle column could however be an interesting options for smaller or temporary projects.

Awareness about our planet is more important than ever before. Thereby, the transition towards a Circular Economy (CE) aims to keep products in use and to design out waste. In the construction industry, one way of reducing the use of raw materials is by transforming waste residuals from demolition projects into resources to be reused. By implementing these resources in new buildings, the supply of harvested (structural) elements and the demand for resources in new buildings can be matched. Due to the high amount of embodied carbon in superstructures, this research focuses on the reuse potential of harvested concrete (structural) elements in the design of new buildings. The demolition and construction of buildings are analysed from the point of view of structural engineers with an extensive literature study, interviews and a case-study. This resulted in the process of ‘Deconstruct & Reuse’, which includes all information required to assess the reuse potential. The assessment is made operational in the Decision Support Tool, which makes this research the first of its kind. For use in practice, the Decision Support Tool is validated and verified with a test-case that considers the disassembling of De Nederlandsche Bank (DNB) in Amsterdam. In the Decision Support Tool, the test-case is executed by the researcher and by experts resulting in remarks, opportunities, challenges and further research. In conclusion, the Decision Support Tool has a high practical value as it stimulates the reuse of concrete elements through an operational method. The output provides valuable insights with which a structural engineer can decide if a harvested (structural) element can be reused and implemented in a new building. Hence, the assessment of the reuse potential is considered to be a step towards circularity in the construction industry.

The application of vertical forests in the building industry is a popular development with promising advantages regarding sustainability. However, placing trees along a façade gives additional loads which often results in extra material use. This is undesired concerning building design, costs, and the environment. To mitigate these adverse effects, trees could be used as load-bearing structural elements. To increase the stability of such elements, it might be advantageous to connect the trees to each other. Such connections can naturally be created with inosculations: self-growing connections in which the bark and inner tissue of two trees merge. Applying living trees as structural elements requires a deeper understanding of both the botanical and structural behaviour of trees. Likewise, more must be known about the botanical and structural behaviour of self-growing connections. This research expands the knowledge on the topic of using living trees as structural elements, both as single tree elements and self-growing interconnected tree elements. This aim is reached by proposing a structural model of (interconnected) trees, which is verified by comparing the outcome of the model with the outcome of winching tests. Furthermore, a design is made in which living trees are used as structural elements in a vertical forest case study. This lays the groundwork on how to approach a living tree design, both from a structural and botanical point of view. The structural model is verified by carrying out winching tests on the Living Tree Pavilion, including one single tree, one pair of cross-connected trees and one pair of parallel-connected trees. Additionally, winching tests are performed on a tree in an airpot, in which boundaries constrain the root system. During the winching tests, a force is applied to the tree system, and the elongation is measured on several locations of the tree, providing insight into the strain distribution. Additionally, the displacement of the trees is measured at the height of the force application. Based on geometry measurements, the trees are modelled as solids in a finite element software. From the models of the interconnected trees, a compound solid is created which behaves like a single solid. The winching load is applied to the models to allow for a comparison between the results of the winching tests and the models. The geometry measurements show indications that leaning trees create an oval cross-section, which is influenced by the presence of inosculations. The winching tests show that an unconstrained root system is stiffer than a root system constrained by an airpot. Furthermore, the tests show that interconnected trees do not have favourable stiffness qualities compared to single trees. A comparison between the model and test results indicates that the finite element model is a plausible representation of reality for the single tree, the parallel-connected trees, and the out-of-plane results of the cross-connected trees. The finite element model fitted poorer with the in-plane winching test results of the cross-connected trees. More research is needed to determine whether diverging tree characteristics, in the direction that is rarely subjected to loads, could explain the discrepancy in measured and modelled behaviour. Two designs are created in which living trees of the Wonderwoods vertical forest carry the loads of a plant container. There are three reasons why cross-connected trees are not favourable over a design with single trees. First, the single trees can bear the plant containers at a younger age. Second, the risk of trees not creating suitable inosculations is high. Third, as interconnected trees share one container, the competition for space can become fierce. This research concludes that a system of interconnected trees as structural elements is not favourable over a system of single trees. This is mainly because no clear advantages in terms of strength and stability could be found in both the winching tests and the design for Wonderwoods.