This thesis investigates the performance of inkjet-printed electrochromic (EC) glass compared to traditional triple glazing with roller shades in an office setting in the Netherlands. The study aims to assess thermal and visual comfort, via a live experiment conducted in a controlled environment. Key performance indicators (KPIs) include thermal sensation & preference, solar heat perception & satisfaction, (day)light adequacy, colour rendering satisfaction, view clarity satisfaction, and glare perception. Results indicate that EC glass outperforms traditional glazing in maintaining thermal comfort, particularly in darker scenarios, although both glazing types keeping room temperatures within a comfortable range. Visual comfort results are mixed; EC glass provided better daylight sufficiency in low-light conditions, while traditional glazing offered better performance in bright conditions. User satisfaction regarding colour rendering and glare did not show significant differences between the two façade types. This study was limited to the winter period of the Dutch climate. Ideally, to obtain a complete picture of the performance between both facades, this experiment should be conducted again during the summer period or in a warmer climate.

Flat glass is a widely used material in the construction industry. However, its production has a relatively high carbon footprint due to the high melting temperature required, and most of it is still sent to landfill or down-cycled at end-of-life. The reuse of glass therefore has a great potential, given its lower carbon footprint and the number of existing buildings with glass panes that would be suitable for reuse.
This research project aims to propose a novel methodology for estimating the potential of tempered glass for adaptive reuse. It is illustrated with a case study of a historic building in Paris, built over 50 years ago with about 2500 fully toughened glass panes for potential reuse.
Firstly, a brief environmental impact assessment quantifies the impact of reuse compared to recycling and down-cycling to provide a more critical understanding of the benefits of reuse.
Secondly, a probabilistic equivalence of the Heat-Soak Test (HST) is justified for thermally toughened glass. Based on statistical analysis of spontaneous breakage due to nickel sulphide (NiS) inclusions over time, a safety level over time is estimated. This level of safety can already be considered quite high from 20 years after installation and is equivalent to an HST after 50 years.
Finally, the residual strength of aged tempered glass is estimated. This strength is based on the combination of the pre-stress level and Linear Elastic Fracture Mechanics (LEFM). The pre-stress level and the largest flaw depth are measured on-site using portable optical devices on a representative sample. A visual inspection procedure is then defined to speed up the evaluation of the flaw depth. Once trained, the observer should be able to qualify the glass panes relatively quickly following different 'Quality Levels' with associated characteristic strengths (95% confidence level).
This methodology was applied to the case study. Pre-stress and flaw depth measurements were carried out on 70 glass panes. Visual inspection was tested and the margins calibrated to reach a 95% confidence level. The glass panes have an average surface pre-stress level of 81.41 MPa with a standard deviation of 4.17 MPa, which is consistent with other values reported in the literature for fully toughened glass. The largest flaw depths ranged from 4 µm to 147 µm, also in agreement with other publications. All of the glass panes analysed are suitable for reuse as heat-strengthened glass, and potentially better for some of them.
The proposed methodology has been summarised to be generalised to other reuse projects. Typical fully toughened, heat-strengthened and annealed glass (average pre-stressing level and surface quality based on previous measurements) have a great potential for reuse at the same characteristic strength if the surface quality estimated by visual inspection has flaw depths smaller than 20-40 µm. Qualification for reuse of these three types of glass with a reduced strength is also proposed. This could allow reusing glass panes with flaw depths of up to 500 µm for several design scenarios.

This research has aimed to investigate the possibility of applying a neural network algorithm into the structural design process of bascule bridge leaves, by creating a workflow in Grasshopper. The demand for this tool, originates from the fact that the current design process is experienced as linear and slow, and does not fit the dynamic design environment within Amsterdam.

The foundation for the generative design workflow, is a parametric model for an orthotropic bridge deck made out of steel. The model is made out of main beams, which are modeled as tubular profiles, cross beams and rib elements, which are modeled as line elements, and a bridge deck plate on top, to which all elements are welded. The parametric model is controlled by a total of 24 parameters which describe its dimensions, profiles and spacing of elements. Based on the user input for three parameters, namely the bridge deck length, bridge deck width and distance to the rotational axis, the neural network algorithm does a suggestion for the remaining parameters, based on information in the bridge database. The bridge database consists of 35 bascule bridges. A design for a steel bridge leaf is then generated. In the next step, the generated structure is forwarded into SCIA Engineer via a.xml file, for structural analysis. Within SCIA Engineer, the structural performance is assessed based on occurring Von Mises stresses under defined load combinations.

In the validation stage of the research, three steps were undertaken. In the first validation step, the predicting behavior of the neural network was optimized based on the mean squared error. The predicting behavior of the workflow was assessed using 5-fold cross validation. It appeared that the neural network had a prediction accuracy of 25.91%. Therefore, in the second validation step, the neural network’s complexity was reduced. In the improved model, the neural network predicts fourteen parameters. The total predicting accuracy of the improved model is equal to 61.07%.In the last validation step, five random cases were generated, of which their SCIA model output was compared to simplified models and the predicting behavior of the neural network was assessed. In two out of five cases, the neural network immediately suggests a good structure, while in two others, only one parameter had to be altered to create a viable structure. From validation of the SCIA models, it appeared that the moment, shear force and stress distribution for both the main beam and crossbeam showed consistent behavior through all five models. For the main beams, a simple MatrixFrame model was constructed for comparison. There were significant differences in the magnitude of occurring moments and shear forces between the MatrixFrame model and SCIA model. The magnitudes of moments, shear forces and stresses in the cross beams were compared to a hand calculation of a clamped beam. It was concluded that the SCIA models generated in the validation stage of the research, behaved correctly.

In the results section, the output of the workflow was compared to two reference cases, the Berlagebrug and Elizabeth Admiraalbrug. For the Berlagebrug, the SCIA model had such a significant error that no useful results could be extracted from this case study. For the Elizabeth Admiraalbrug, the workflow generated a structure which was approximately twice as large in steel mass. This has resulted in lower unity checks compared to the original design. A qualitative comparison between the current design process and when the created workflow would be implemented, was also done.

Based on the quantitative results obtained in the research, it was concluded that the neural network algorithm in the application developed in its current form, will not significantly improve the structural design process, due to a lack of consistency in generated results.

Many countries such as Brazil, have a low percentage of recycled container glass due to multiple factors, such as inadequate waste collection and recycling infrastructure, low public awareness about recycling’s significance, and insufficient laws to promote it. In addition, the country faces high levels of homelessness and inadequate housing. As a result, an increasing number of builders are exploring repurposing glass bottles as a construction material for walls, occasionally incorporating them into traditional earthen building techniques. Therefore, this thesis investigates the potential of repurposing glass container bottles for the construction of load-bearing walls for affordable housing in Brazil while at the same time reducing pollution, enhancing aesthetics, and promoting environmental friendliness.

The main research question is formulated as follows:
How can the structural feasibility of re-purposing beer bottles in Glass Bottle Earth Bricks (GBEB) for wall constructions be ensured?

The report consists of four parts, which are created for each research area: state of the art, experimental investigations, numerical investigations, and finally the discussion, conclusion and recommendations section.

The literature review underscores a rising trend of incorporating glass bottles into earth-based constructions, driven by their shared advantages of environmental friendliness and affordability. Nevertheless, challenges emerge in connecting glass bottles when constructing walls with mortar due to their irregular shapes. To enhance construction efficiency and quality, innovative methods entail pouring mortar between the bottles rather than applying it manually. This approach is complemented by creating bricks while using molds where the bottles are placed inside, facilitating easier stacking and faster execution. The
direct integration of glass bottles into bricks further expedites the process. Prefabricating these blocks with pre-placed glass bottles in controlled environments further optimizes efficiency.

During experimental investigations, a self-compacting earth-based mortar mixture is formulated using local Dutch soil from Emmen. Five different mixture designs are explored, utilizing both artificial and natural soil. The mechanical properties of the earth-based mortar mixtures are evaluated through compressive and flexural strength tests, as well as a mini slump flow test to assess workability. The selected earth mixture is anticipated to achieve an average compressive strength of 12.1 MPa after 28 days, an average flexural strength of 3.67 MPa after 7 days, and a flow diameter of 23.05 mm.

Subsequently, a prototype glass bottle earth brick containing a horizontally aligned longneck beer bottle is produced, revealing a compressive strength ranging between 8.21 and 11.40 MPa after 28 days of casting. Upon failure, a fracture analysis indicated that the origin of failure lies at the bottom of the bottle, with breaking stresses at failure measuring 608 kg/cm² and 431 kg/cm² for two samples.

Results from SEM-EDS analyses reveal iron and aluminum residue at the fracture origin in the glass bottle. The earth mortar cast around the bottle showcases a similar composition, suggesting that scratches were likely introduced during brick manufacturing by the earth mixture. Additionally, an initial evaluation of the thermal behavior of the Glass Bottle Earth Brick (GBEB) indicates that the mortar acts as a heat sink, suggesting that the GBEB could contribute to thermal comfort.

Through numerical investigations employing Finite Element Methods (FEM), a comprehensive understanding of stress propagation and behavior within a Glass Bottle Earth Brick is achieved. Modeling the brick with the bottle from laboratory experiments aligns with expected peak stresses. However, the Finite Element Method (FEM) model's simplification disregards knurls, the ribbed patterns commonly present on the outer bottom surface of the bottle. Simplifying the model by removing the knurls lowers the computational complexity but potentially overestimates the strength of the GBEB. This underscores the importance of considering knurls to accurately predict peak stresses.

Based on these findings, it is inferred that repurposing glass bottles for constructing walls capable of supporting small-scale structures is feasible. However, since this represents a novel building approach, it demonstrates potential while also highlighting the need for further investigation and clarification. Increasing the number of samples tested and expanding the range of factors examined can enhance confidence and provide insights into the material results and assumptions made.

The main focus of this thesis is on a thin glass sandwich panel combined with a three-dimensional printed core pattern. The core pattern provides stiffness to the panel, but it also influences the daylight transmission. The goal of this research is to design a façade system which can dynamically improve the daylight performance, effectively control the illuminance inside the building together with preventing disturbing glare.

The research first evaluates the theory behind thin glass, the structural sandwich structure and how the design of a façade panel correlates with its visual comfort. The properties of existing dynamic systems are evaluated, together with exploring other possible dynamic systems that can be integrated in the panel.

The resulting system, a hexagonal core pattern with integrated inflatables, is evaluated on its structural performance and daylight performance using analyses executed in the grasshopper model. This is further expanded by studying the structural performance of more complex core geometry using Diana Finite Element analyses. From the results of these evaluations, a design strategy is created which is able to find the optimal properties of the inflatable façade system.

This design strategy is then applied to a case study, to show both the design of a single façade panel, as well as the full façade system of the whole building. The final result is the design strategy for the dynamic inflatable façade system.

An investigation into the application of additive manufacturing to the production of structural joints was conducted for this thesis. The main goal was to determine all necessary aspects that someone needs to consider when designing a structural part that is intended to be printed with additive manufacturing. As an example, the branched column connection was selected due to its inherent limitations, which can be effectively addressed through the integration of additive manufacturing techniques.
Within the construction realm, wire arc additive manufacturing (WAAM) stands out as particularly advantageous due to its ability to yield high mechanical properties comparable to conventionally manufactured materials, coupled with a high deposition rate. As with any manufacturing process, WAAM operates within certain constraints dictating the types of objects feasible for production.
To ensure compatibility with WAAM while achieving desired structural and aesthetic benchmarks, three laboratory tests were conducted. These tests scrutinized the impact of input process parameters, overhang, and overlapping on the quality of the build. Factors such as travel speed, wire feed speed, voltage, and current were examined for their influence on welding bead dimensions and quality. Additionally, an investigation into how the percentage of overlap affected print quality was done. Among the constraints, the most pivotal one was the overhang limitation, determining the minimum allowed overhang angle in perpendicular and parallel directions depending on the direction of the print.
The primary objective in designing the connection was to reduce the necessary material for the branched column connection’s manufacture. Topology optimization (TO) played a crucial role in achieving this goal. Various models were constructed, each differing in TO input parameters to find the model with the lowest required mass while maintaining adequate structural performance. These models varied based on TO objectives (equivalent von Mises stress, compliance, mass, and volume) and TO constraints (either mass retain percentage or maximum stress), while also integrating manufacturing constraints obtained from lab tests. Ultimately, the model that offered the lowest mass and satisfactory structural performance focused on compliance as its objective, while retaining 15% of its initial mass.
Based on the above explained research a design guideline could be proposed and includes all necessary steps and considerations that someone needs to take into account when designing a connection manufactured with WAAM. The steps of the guideline include: 1. Selection of additive manufacturing process; 2. Material selection; 3. Determination of additive manufacturing process manufacturing limitations; 4. Design phase including TO with the proposed input parameters.
In illustrating the advantages and limitations of WAAM in the construction industry and proposed design guideline, a case study involving a comparative analysis between a steel plate and a WAAM branch column connection was done. This study centered on the real life project, 6 Bevis Marks in London. The findings showcased a notable reduction in the required material. However, the limitations of this approach were apparent in the increased manufacturing time and costs.

The Netherlands is grappling with a substantial housing crisis, marked by an estimated shortage of 380,000 houses. To address this issue, an annual creation of 100,000 new housing units is deemed necessary. However, the current construction rate stands at only 70,000 houses per year, indicating a considerable gap in resolving the housing crisis. Recognizing the potential of urban densification, especially through vertical extension using Cross-Laminated Timber (CLT), presents a sustainable solution. Nevertheless, challenges arise, such as the unique approach to vertical extension and the structural constraints posed by CLT's lower strength compared to materials like concrete.

This research aims to identify the vertical extension potential of CLT in existing buildings by developing a parametric tool that considers various structural constraints. The ultimate goal is to contribute to informed decision-making practices for sustainable and effective structural design in vertical extensions.

The methodology comprises four phases: analysis, synthesis, simulation, and evaluation. The analysis phase examines existing vertical extensions, structural context, and spare capacity concepts, forming the basis for synthesis. A parametric tool is then created using Grasshopper and Karamba, employed in the simulation phase to conduct a parameter study based on the analysis phase findings. This study assesses the effects of the original structure's base geometry on spare capacity and evaluates the design of the extension itself.

The results of the parameter study reveal that the presence and placement of a stability core have the most significant impact on spare capacity in the existing building. The original construction grid and building height also influence spare capacity, though to a lesser extent. Additionally, wall layouts in the extension, such as core alignment, functional design, and façade-aligned layouts, significantly affect spare capacity utilization in both the original structure and the extension.

Variations in extension grid show differences in spare capacity utilization, with effects smaller in magnitude compared to wall layout variations and displaying less dependence on the original structure's geometry. In the vertical extension itself, failure tends to concentrate on connections between CLT panels and floors, particularly with wall layouts emphasizing functional design.

In conclusion, the research, coupled with the development of a parametric tool, successfully achieves its main goal. The tool's accuracy is validated through extensive assessments of horizontal load transfer from the extension to the original structure. The parameter study highlights the significant effects of various parameters on extension design and the original structure, emphasizing the tool's utility in exploratory design stages for vertical extensions.

The circular potential of existing aluminium curtain wall facades is investigated in this study. The focus is primarily on reuse, refurbishment and re-manufacturing, aiming to raise the value of materials that have not yet reached the end of their service life. The increasing concern about resource depletion, damage to the ecosphere and the need for sustainable development increases the demand for sustainable strategies in many industries. The building industry is one of the most polluting industries at current times and with governments incorporating laws regarding these topics, the need for methods to reduce the impact in this industry is needed. Facades have a great impact on the whole life carbon impact of a building and show potential for reuse. Scheldebouw, a facade producer in the Netherlands, connected to Permasteelisa, is looking for possible ways to make the construction industry more sustainable. This study aims to reduce the take-make-dispose culture, by creating circular strategies for existing curtain wall facades. It was observed that those facades lose their function before their end-of-life stage is reached. The remaining value and potential that was wasted in this case could be avoided.
The objective of this thesis is to develop strategies to reuse existing aluminium curtain wall facade elements, to diminish waste and reduce resource depletion. To quantify the impact of these strategies the life cycle analysis is used to calculate the amount of emitted carbon. A mixed-method research was conducted, which involved integrating interviews with experts in the facade and material industry along with a review of literature, resulting in the development of a qualitative understanding. Integrating this with reference studies, the application of reuse was further examined. Lastly, strategies have been formed, which have been applied to a relevant case. Facades do have the potential for reuse, as demonstrated in this study. Facades play a crucial role in enclosing indoor spaces, which leads to various specific characteristics that make both facade structures
in themselves and in their reuse rather complex. Facade systems are often uniquely developed, making it difficult to locate a match for reuse. Eight general strategies have been defined to create incentives for reuse. A method for calculating the avoided carbon was created to quantify the potential of the strategies and provide an incentive for clients to include these circular strategies. Overall, the research outcomes offer a framework that has the potential to reduce resource depletion and increase value retention in the facade industry. Crucial elements were determined and components that show potential for reuse were defined. Risks and uncertainties have been identified, as well as the need for
incentives for producers, clients, and policymakers. As mentioned above, finding a receiving project that matches the donor material and designing with these materials still appears to be difficult. Regarding carbon emissions, beneficial strategies were defined. Refurbishment can achieve an 86% carbon reduction with 99% of the materials being reused. Re-manufacturing offers a 49% overall carbon reduction with a 59% material saving. Challenges lie in glazing reuse, particularly sealant and spacer components. Implementing re-manufacturing with glass replacement saves 27% embodied carbon and reduces waste by 21% at the donor building and 28% in the product and construction
stages.

The recent developments in the building industry to build more sustainable should result in the use of light constructions with a low environmental impact. Timber is a suitable material for this purpose. To reduce the environmental impact of a building, an improvement in an often used structural element can have a significant impact on the sustainability. Floors are a large part of the material consumption of building. A challenge with lightweight timber floors is the vibrational performance of the floor due to walking humans. Conventional concrete floors are less sensitive to vibrations due to their large weight. The vibrations of the floor have influence on the comfort of the humans residing on the floor. Furthermore, concrete is generally seen as a less environmentally friendly material than timber. This raised the main research question of this thesis: How do vibrational performance levels influence the sustainability of several timber floor systems, considering multiple design configurations, compared to conventional concrete floor systems?

The floors used in this research are a CLT floor, LVL box floor, TCC floor, concrete cast in situ floor and concrete hollow core floor. For the research on the vibrational performance and sustainability of floors some methods for assessment are used. For the vibrational performance the assessment method from the renewed Eurocode 5: Timber structures is used. This assesses the resonant and transient vibration response of the floor and checks them with predetermined vibrational comfort criteria. For the assessment of the sustainability the environmental cost indication is used. This method assesses several environmental impact categories and weighs their impact onto the environment, separately the global warming potential is also assessed by the CO2eq emissions of a material.

The result gathered from the research show that timber floors are more sensitive to vibrational performance than concrete floors. Floors with a high vibrational performance need a significantly higher floor height than low performance floors. The influence of damping and floor configurations is important for the vibrational performance. The environmental impact of timber floors have an advantage when biogenic carbon is taken into account. Concrete floors can reach longer floor spans and for high performance floors have a lower increase of environmental impact than timber floors. For the environmental impact of a floor, reuse or recycling is important for the end-of-life scenario.

To draw a conclusion to the main research question; Vibrational performance of floors do effect the environmental impact of the floors. High performance floors have a significantly higher environmental impact than low performance floors. The environmental impact of concrete floors increases less for higher floor performances than timber floors. Timber floors are more sustainable within their technical feasibility. The floor configurations can mitigate vibrations and can thus reduce the environmental impact of the floors.

The present Master thesis explores the implementation of a glare-based control strategy for Venetian blinds in buildings with totally transparent facades. The case study concerns the Co-Creation Center, a building that hosts three different types of events: presentations, meetings and workshops. The diverse occupancy patterns, coupled with the four fully glazed facades, make the effective blinds control a challenging task to achieve using a traditional rule-based approach. Therefore, in this project, an optimized control system is proposed, aiming at the minimization of visual discomfort due to glare, as well as the minimization of energy demands for electric lighting by increasing daylight entry. The control strategy is developed within Grasshopper, a promising tool for parametric and optimization problems. Grasshopper allows for the creation of a parametric model that can be adjusted to other similar buildings with fully glazed facades by modifying the input parameters. Radial Basis Function Optimization (RBFOpt), a model-based optimization method performed by Grasshopper’s component Opossum, is utilized for the computation of the optimal blinds’ states. within the developed control strategy, Ecyl is used as a glare index, giving the opportunity to evaluate its performance. Results show that the developed algorithm can improve the existing visual conditions in the Co-Creation Center by an average of 80% for all activity types, although it led to an average increase of 7% in the time steps where electric lighting is needed, in comparison to the current control. Nevertheless, the time-consuming ray-tracing process performed by Grasshopper for each time step and the non-automated use of the RBFOpt component Opossum, slowed down the optimizations and made their use rather unsuitable for real-life implementation of the control strategy. Despite the impractical use of Opossum, RBFOpt was proved a promising optimization method. Finally, Ecyl displayed an overall agreement of 92.5% with DGP, proving that in spaces with multiple windows and uncertain occupants’ view direction, a view-independent index can predict glare risks adequately well, after being carefully correlated with another reliable view-dependent metric.

The reuse of insulating glass plays a crucial role in promoting sustainability and circularity within the construction sector. CO2 emissions must be reduced according to the Climate Agreement. Reusing materials can help achieve this goal. Reusing glass without reheating it can provide environmental and cost benefits, making it a suitable option. In this study, 36-year-old insulating glass panels (double-glazing) from an apartment building in Amstelveen have been tested for strength through destructive testing. This is done to see what the strength of the glass is after the glass has been in the building for 36 years and has been exposed to opportunities for damage. Various patterns of damage on both the interior and exterior side of the glass panels from an insulated glass unit affects the strength that can eventually be assigned to the glass. The aim of this thesis is to be able to show whether and how insulated glass units can be reused and what the strength is of naturally aged glass after a certain lifetime. From six insulated glass units obtained, specimens measuring 150mm x 150mm are extracted and tested for strength using a Coaxial Double Ring test. Prior to the destructive tests, a number of specimens were viewed under the Keyence VHX 7000 digital microscope to see how the damages are and whether they vary between the four sides of an insulated glass unit. This revealed that the outer side of the outer panel (side #1) contains the most and homogeneous damage. Weathering, especially rain and wind, which can bring sand particles, for example, create homogeneous damage on the glass surface. The entire surface is exposed to this type of weathering. The outer side of the inner panel (side #4) also contained quite a lot of damage from probably cleaning and (human) touching. Despite the fact that the inner sides of both panels (the sides in the cavity, side #2 and #3) theoretically had little potential for weathering, damage could also be seen on these, although it was more localised, meaning it probably occurred during the production process or preparation of the specimens for this experiment. During the Coaxial Double Ring tests, 406 specimens were tested for strength. The strengths of the specimens ranged from 16.8 MPa to 243.7 MPa, with an average strength of 67.5 MPa. The average strengths of side #2 and #3 (sides in the cavity) are slightly higher than those of side #1 and #4 (outer sides), between 9% and 17%. A tin-tester was used to determine which side of each specimen was the tin-side prior to the strength tests, to include this in the analysis of the results. The specimens tested on the tin-side were found to be on average much weaker than the specimens tested on air-sides. The average measured strength of the air-side is 31% higher than that of the tin-side. In a number of tests carried out with new glass, this large difference is already present, while literature states that the difference in strength between the air- and tin-sides can be considered marginal. Fracture statistics were used to analyse the data and find a strength for each series tested. This was done using Weibull theory. The two-parameter Weibull distribution has proven to be very conservative at low failure probabilities, resulting in a very low design strength (failure probabilities of 0.8% and 0.12%) for a series of specimens when there is a large spread in data. The spread in data was often of greater influence than the values of the measured strengths. As a result, the design strengths for series tested on the air-side were usually lower than specimens tested on the tin-side, while the average strength measurements were actually higher. The greater variation in strengths of specimens coming vi from the inner side #2 and #3 results in lower design strengths than the outer sides (#1 and #4), which contain more (homogeneous) damage. The values of design strengths of the naturally aged glass tested were almost always lower than the design strength of new glass according to current standards. The design strengths of new glass are 22.5 MPa according to NEN2608 and 25.0 MPa according to EN16612. When looking at how many specimens failed at stresses lower than these values, there are only three and six respectively. So, there are very few spots in 36-year-old glass that are weaker than the design strength that can be assumed according to NEN2608 or EN16612. These lowest values are not consistently found in specimens tested on either the air-side or the tin-side, so based on this study, the influence of this can be ruled out. By this means, a more realistic and less conservative option seems to be to take the strength of the weakest specimen in a test series and then assign it to the entire panel from which that test series comes. Reuse options are discussed in the final section of this thesis. Using a number of common glass structures, it explains the ways in which weathered glass can or cannot be reused and in what function. How the results obtained can be handled and used is a point of discussion, as the values are not always representative of the strength of the entire glass panel. Further research will have to show whether the current design standards and the parameters used in them are well chosen or whether they should be different for used glass. For example, use a lower material factor of 1.35 instead of 1.6 – 1.8 when calculating the design strength or use a higher failure probability than 0.0012 to determine design strength in a Weibull distribution. The efficiency and effectiveness of the method used can also be optimised in further research.

This thesis investigates the usability and creation of a multi-criteria optimisation tool for a facade element consisting of two outer glass layers and a 3D-printed core. The chosen constraint is related to the structural requirements laid down by the NEN codes based on the ULS and SLS. The criteria are: the transparency criterion, which maximises the transparency of the panel; the insulation criterion, which minimises the U-value; and the daylight criterion, which maximises the indirect sunlight at the summer solstice and the total sunlight during the winter solstice.

Topology optimisation is the first considered optimisation algorithm that allows for complete freedom of the core design through discritisation of the core volume with finite elements. Nevertheless, topology optimisation is not considered usable in this tool as a result of the inability to add relevant criteria to topology optimisation integrated into software, the complexity of developing an optimisation tool with topology optimisation in Python or Matlab, and the intricate optimal core designs, which are not easily printable.

Next, a hexagon structure is used as the core design with some related variables, and it is created in Rhino 7. The daylight criterion is performed with the Ladybug library, and a mesh sensitivity study is conducted. The structural constraint uses Karamba3D, and Karamba3D’s accuracy is investigated with validation with Diana and stiffness experiments. The experiments revealed a large discrepancy between the stiffness observed in the experiments and the predicted stiffness in the Karamba3D and Diana models. The insulation and transparency criteria are added, and the genetic algorithm is used to determine the near-optimal solution. Finally, a case study based on the Echo building is used to compare the near-optimal sandwich panels with regular windows. Although the computational demand inhibits quick results, the sandwich panel performs well compared to the original window in relation to the three criteria.

This thesis project proposes the introduction of bio-based materials in the design of unitised curtain wall façade systems. The work investigates a circular bio-based unitised façade design to understand its feasibility regarding thermal, technical, and environmental performance. The research is divided in four phases, including the material, system design, performance, and environmental assessment level.
The material phase serves as a literature review to study the current technologies and available bioproducts in the market to make an informed selection. Once the materials are selected, the system design phase starts with an emphasis on dynamic construction and design for disassembly features.
Overall, this study aims to minimize reliance on non-renewable resources such as aluminium in façade systems. Therefore, it is important to analyse the thermal and hygrothermal behaviour of the materials to integrate design characteristics that can improve their performance while protecting their structural integrity.
After the feasibility of the design concepts gets validated, a comparative environmental assessment against standard aluminium façade systems is conducted to quantify the sustainability impact of the proposed system. Ultimately, the research project proposes a detailed exploration into the feasibility of circular, bio- based unitised façade systems. Therefore, the introduction of bio-based systems that support sustainable methodologies and practices from the material, design, and system level is demonstrated.

Seismic events have shown the hazardous and expensive consequences resulting from seismic damage of non-structural elements. For this reason, the concern regarding the seismic performance of glazed curtain walls has acquired more relevance in the building industry; however, there is still a gap of information in the literature about this topic. To contribute with a broader panorama about the seismic performance of CW, this thesis project is focused on the seismic of the connections within a curtain wall.
This thesis intends to evaluate the performance of the connections that contribute to the seismic response of a glazed curtain wall with finite element models and experimental tests. To achieve this objective, several important points were taken into account. First, a literature study to understand what is a CW, and which are the components that may have influence in seismic design. Second, the two case-studies considered in this research are presented; in this section information about the specimens tested and types of tests performed is provided. Third, elaborate finite element models of the connections corresponding to each case study describing the criteria used. Finally, a comparison between the experimental and numerical results is elaborated to determine if the modelling approach is correct.
The experimental tests were carried out with the collaboration of Permasteelisa Group, and the numerical models were elaborated with DIANA FEA software. Five connections were analysed in this research: mullion to mullion, transom to starter sill, top aluminium bracket and hook, starter sill- bottom steel bracket, and silicone by a non-linear analysis with incremental displacements. At the end of this analysis it was observed a good agreement in the behaviour of the frame to frame connections with a minimal over estimation of the stiffness of certain frame to frame connections. Regarding the connections involving brackets, it was observed that the behaviour in the in-plane horizontal direction can be affected by the rotation of this elements because bolted connections shall be modelled as rotational springs. Finally about silicone it was observed that there exists a good match between the experimental results and the numerical models.
In conclusion, the modelling procedure was validated with experimental tests with relatively optimal results. Nonetheless, there are still limitations in the development of this topic that will be described in the recommendations but much more openness is expected in the future in terms of research on this topic.

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.

Cold-bent insulating glass units (IGU) have the potential to be one of the answers to current needs and wishes of modern and sustainable architecture. Curved glass is stiffer against out-of-plane loads and therefore the structural behaviour of cold-bent IGU’s is different compared to flat IGU’s. Structural behaviour of flat glass in buildings is assessed using standards such as EN 16612 and NEN 2608. Within these norms, isochoric and load sharing cavity pressures are assessed using simplified analytical equations. In case of cold-bent IGU’s, the additional assessment of increased stiffness, permanent cold-bending stresses and optical distortions are of importance. Currently, no standards are available for building envelopes containing curved glass elements. Methods from current standards have proved to be sufficient to quantify the complex role of cavity pressure in flat IGU’s. The goal of this research is to develop an analytical method to determine the effect of cavity pressure on the structural behaviour of cold-bent insulating glass units.

For the structural assessment of cold-bent IGU’s three stages are defined: ’Bending phase’, ‘Fixation moment’ and ‘Use phase’. Numerical models are developed to gain insights into the structural behaviour of cold-bent glass plates. Insights are then used to derive and validate simplified analytical methods.

The bending phase is numerically modelled with a geometrically nonlinear analysis in which curvatures are realized by prescribed displacements along two opposite edges of the plate. Results show that maximum cold-bending stresses are independent of plate size. By defining a tensile bending strength, insights are gained into the maximum radius of curvature of a plate with a specified thickness. A closed form equation is derived, which is used to calculate cold-bending stresses considering plate thickness and radius of curvature as input parameters. Resulting principal stresses have an average accuracy of 99.1% compared to numerical outcomes. Validity of the cold-bending stresses is limited to linearly fixed plates, up to a size of 6x3m, with equivalent plate thicknesses ranging from 4-20mm and design radii ranging from 3m to 25m.

Numerical results from the fixation moment show an anticlastic double or triple (w-shape) curvature in single curved plates, that cause optical distortions. The extent and shape of anticlastic bending depend on the Poisson’s ratio, plate thickness, radius of curvature and plate size. Based on regression between the parameters of influence, a result-based approach is developed to determine anticlastic bending displacements at the centre of curved plates. The approach is simplified to a curved plate with a sinusoidal anticlastic bending curvature. The displacements are expressed in a parameter for the radius at midspan and are calculated using tabulated coefficients with an average accuracy of 99.3%. Validity of the radius at midspan is limited to the previously mentioned boundary conditions.

For the use phase, the calculation of cavity pressures depends on the volume of deformation per pane of a linearly supported cold-bent IGU. Interaction between the panes is modelled using pressure loads derived from Boyle’s law. Using numerical models, volumes of deformation (v) from curved plates subjected to pressure loads (p) are presented in P-V diagrams. These diagrams are used calculate cavity pressures ranging from -1 to 1 kN/m2, considering plate sizes up to 6x3m, plate thickness of 8, 10 and 12mm and design radii up to 8m. Due to the increased stiffness of curved IGU’s, a higher load is shared by the pane onto which an external pressure is applied. Furthermore, as a result of anticlastic bending, a permanent isochoric pressure is present inside cavities of asymmetric IGU’s, which increases as curvatures increase.

A simplified analytical method to calculate effective cavity pressures is derived from shell theory. Load sharing pressures of symmetric IGU’s are calculated with an average accuracy of 95%, compared to results from the numerical P-V diagrams. Load sharing pressures of asymmetric IGU’s (91% accuracy) are summed with isochoric pressures due to cold-bending (92% accuracy) to calculate combined effective pressures with an average accuracy of 87%.

The equations are summarized in a guideline, which is complemented by an interactive calculation tool. The developed analytical method is effective in calculating effective cavity pressures and can be used to quickly explore various design options in a wide range of cold-bent IGU’s.

Since the oil crises during the 1970s, there has been a growing awareness of thermal losses through windows in buildings. Nowadays, double-glazing is a common product for moderate maritime climate. In the Netherlands two permit requirements are calculations regarding nearly zero energy and environmental performance of a building. In order to reach nearly zero energy buildings, triple glazing and even quadruple glazing is considered as possibility. This has negative affects on the environmental performance of a building, because glass does need a lot of resources for production. A solution to that challenge could be the application of thin glass sandwiches, a structural sandwich with two ultra-thin faces (0.5mm) of glass. The structural sandwich is common in the aviation industry to stiffen and strengthen an element without adding significant weight. Downside is the increased conduction through the core material. Question is: to what extent can a thin glass sandwich panel, compared to regular insulated glass units, counterbalance its decreased thermal performance by reducing embodied energy during production? This research focusses on the material choice, quantity and distribution in the core of a sandwich panel in order to maximize thermal performance for a moderate maritime climate. In order to do so, materials from the CES library are evaluated. Detailed analytical calculations are used to determine the thermal performance regarding different patterns. FEA simulation software is used to determine the thermal performance regarding the cross-section of the actual thermal bridge between the two faces. From this research, the best solution is picked and evaluated on energy consumption, order to identify the effects on a building scale. General trends are identified and transformed into a design for a thin glass sandwich. Next to that, design guidelines are extracted for designers in order to design a thin glass sandwich without the need of calculating.

The research of this thesis focuses on the stiffness and the durability of a composite panel that consists of thin glass as outer layers and a 3D printed core element from recycled PET. Thin Alumino-silicate glass, mostly used in computers, tablets and smartphones, is known for its lightweight, flexibility, durability, high bending strength and relatively low weight. However, the lack of stiffness allows for some safety-issues. In combination with another material, composite panel can be generated. The core element of this composite panel will consist of 3D printed recycled PET. The use of recycled PET has been taken into account, due to the increasing of plastic waste for the next 30 years. A combination of both materials allows for a much stiffer composite panel and reduction in weight of 71,9 % compared to a normal double glazed window panel. The unaffected composite panels showed that the panels returned to its original shape after removing the load. However, the experiments showed that 3D printing reduces the mechanical properties of recycled PET and PET. An overview is presented in this paper of the durability of the composite panel. The durability aspects for this research are UV radiation, elevated temperature and fire. The UV radiation showed that the glue from DELO ensures for a better adhesion , which allows reaching higher forces. Also, the showed to let recycled PET change into a yellowish color and becomes more brittle. At an elevated temperature of 80 ⁰C, recycled PET looses its stiffness and strength and can not take up forces when exposed. Recycled PET has melting temperature starting from 200 ⁰C and during a fire temperatures could reach up to 1000 ⁰C. This allows the core element to melt fully during a fire. The following chapters of this thesis will give an overview of the literature study and the experiments that were performed and how the composite panel can be integrated into a facade. Keywords: Thin glass, Recycled PET, PET, composite, 3D printing, UV radiation, elevated temperature, fire, Honeycomb pattern, Truss pattern.

Research and development in additive manufacturing with concrete has become more widespread over the last decade. The processes developed range from concrete extrusion, to digital fabrication of formworks and the unification of formwork and reinforcement. Although they enable the production of increasingly material-efficient structures, the individual processes still face various challenges such as implementation of reinforcement, geometrical limitations, scaling and formation of cold joints, in particular because of the layer-based process. This research proposes an alternative method of producing concrete formworks dubbed ‘Eggshell’. Combined with a novel casting technique, its aim is to overcome these challenges and make material-efficient concrete production possible. As concrete is the most used construction material in the world its influence on the construction industry is unprecedented. Of the construction costs of concrete, formwork typically makes up 30-80% of the costs. This means formwork considerations are often a key driver in determining the design of concrete structures. Materials used to construct the formwork also have a big impact on the total ecological costs of the concrete building components. As the lifespan of all formwork is finite, this adds to the already considerable amount of waste generated by the building industry. Furthermore, traditional formwork made from steel or wood is ineffective in producing the non-standard, (double) curved geometry that characterizes many contemporary architectural designs. Using innovative means of formwork fabrication, these non-standard building components can potentially be produced in a more cost-, time- and material-efficient way. Moreover, Eggshell opens up possibilities for fabricating structurally optimized geometry, enabling a more efficient use of resources. The research builds upon previous work done as a part of an interdisciplinary master thesis in a collaboration between Gramazio Kohler Research, the Institute of Robotics and Intelligent Systems and the Physical Chemistry of Building Materials group (ETH Zurich). In the thesis a process was developed in which a thin-shell formwork is 3D printed while a fast-hydrating concrete is simultaneously fed in. By 3D printing the formwork, complex geometries can be fabricated effectively. The printed formwork can potentially also be recycled and reused, making the process fully circular. Furthermore, reinforcement can be integrated into the structures, allowing for the creation of structural building components.

In the last decades, the improvement of innovative solutions on windows to achieve sustainability within the built environment is considered as a principal issue. Windows have long been used in buildings for daylight and ventilation. From many studies, health, comfort, and productivity are improved by the well-ventilated indoor environment, because ventilation dilutes the indoor concentration of contamination for indoor air quality. Also, too high indoor air velocity is perceived as draft or chilly, but too low air velocity may create stuffiness. Besides, natural ventilation is one of the most prominent issues of energy consumption within buildings. In summer, cooperated with chimney effect, natural ventilation can reduce the use of the cooling system. Even in winter, the operable window should dynamically adjust the ventilation rates based on actual population to control human CO2 emissions. Consequently, the use of heating, ventilation and air conditioning (HVAC) system will be reduced.
Windows influence the natural ventilation of a building directly and guarantee indoor comfort level, indoor air quality and minimize energy consumption. Windows can be opened manually, or center controlled mechanically. Unreachable windows for instance, in atrium or skylight, are opened by window actuators which are centrally controlled or passively controlled for the reason to optimize indoor comfort. There are advantages using window actuators in terms of controlled natural ventilation. Window actuators can make a significant contribution to a building’s indoor environment and energy performance.
Today it should be easy for the window to control opening sizes for adapting wind direction and wind load, meanwhile, the inlet air velocity should be possibly manipulated to optimize indoor air velocity. In this thesis, the dynamic way of opening windows by using window actuators for the reason of manipulating inlet wind velocity and adapting wind direction and load will be developed. Inspired by that air velocity varies on a curved surface because of curvature changing, inlet air velocity can be manipulated continuously and smoothly by changing window curvature.