Timber high-rise buildings have been gaining in popularity. However, due to the low material stiffness of timber the stability systems of these buildings are often made with steel or concrete. To avoid this the material efficiency of the timber stability systems must be improved. The most material efficient stability systems for timber high-rise are the externally braced systems according to literature. The externally braced systems are the diagrid and external braced frame stability systems. In literature the diagrid is concluded to be more material efficient than the external braced frame. Nonetheless, in practice only external braced frame systems are used for timber high-rise buildings. This disconnect could be caused by the steel connections which are often simplified or overlooked in literature studies but have a large influence on the material usage of a timber stability system. The connections can increase the timber element size because the required connection does not fit, and the connections will decrease the global stiffness of the stability system. For this reason, the connections must be regarded when comparing stability systems. One diagrid and two external braced frame designs will be compared with a parametric model. In this model other parameters will be studied as well. These parameters are: plot sizes of 27.2 x 27.2 m & 27.2 x 40.8 m, floor spans of 3.4 m & 6.8 m, permanent floor loads of 3.5 kN/m^2 & 5.3 kN/m^2 & 6.7 kN/m^2 and element widths ranging from 400 mm to 650 mm. The parametric model will first size the elements individually for the ULS checks and afterwards the elements will be sized per group for the SLS checks. The ULS checks start with a regular ULS member check, then a member check in the fire situation is performed and lastly the connection design component used. This connection design component will create slotted-in steel plate connections where the amount of steel per connection is calculated, and the timber element sizes are increased if needed. In the SLS checks the global lateral displacement is checked and the along-wind acceleration. The along-wind acceleration is often normative for the sizing of the elements in timber high-rise. With a higher global stiffness or higher building mass the acceleration decreases. To make a fair comparison in the results the amount of timber and steel of the internal structure is also added to the material required in the stability system in the façade. From the results it is seen that all buildings are sized on the connection design or on the along-wind acceleration. The diagrid designs have a higher global stiffness so they are sized more often on the connection design whereas the braced frame designs are sized more often on the along-wind acceleration. The diagrid designs use 3x more steel than the braced designs. The results for the other parameters are: Plot size: A smaller plot size requires a higher floor load to meet the acceleration requirement, therefore the large plot size is more material efficient. Floor span: The floor span in the external braced frame has a large influence on the designs with a small plot size. That is because the facade with the smaller span becomes normative for the global displacement. When this happens a smaller floor span decreases the material efficiency significantly. In the larger plot size the influence of the floor span on the braced frame designs is insignificant. For the diagrid designs the larger floor span causes higher normal forces in the diagonals. This increases the material usage in the facade. However, considering the internal structure of the building the large floor span is still more efficient. Floor weight: A higher floor weight is more timber efficient for a small plot size, and the lowest floor weight is the most material efficient for a large plot size. With a higher floor weight, the steel usage always increases since the connection designs are sized on the ULS checks only. Element width: The steel efficiency increases when the element width increases. This is a result of the chosen connection design. The timber usage is similar for all the element widths. Some of the designs with a small plot size and low floor weight are unfeasible since the elements in the facade are too large. This is a result of the choice to only increase the timber element heights and not the connection stiffness to improve the global stiffness. Therefore, it is recommended to study how the global stiffness can be improved more material efficiently. Other recommendations for further research are on the stability system design and the connection design. Since in this thesis many designs are fixed in simplified exploratory studies to decrease the design space of the parametric model.

To stick to climate change targets and reduce global carbon emissions, the building sector needs to adopt a circular economy. In the steel sector, reuse or elements can reduce carbon emissions which are created in today's steel scrap recycling practices. This thesis contributes to closing the knowledge gap on design, costs, and environmental impact score for working with reclaimed steel elements. The tool Steel-IT is created to research the business-case and environmental impact score of low-rise office buildings. Steel-IT uses a donor element database and new office design, which are specified by the user, and generates new and reclaimed steel design alternatives. Using a weight and activity-based costing method, the costs of these design are estimated. Life-cycle analysis is used to quantify the impact. By generating results and analysing the effect of the input in the tool Steel-IT, the following conclusions can be made regarding the business-case and impact score of reclaimed steel in low rise office buildings. A case study using Steel-IT shows that a 25% impact reduction against minimal cost increase is possible. For this, the match between design and donor elements needs to be good. This match can be searched for using Steel-IT. In terms of design, connection detailing is the most critical factor in the success of a donor steel skeleton. Donor steel elements should be sourced from an existing building to limit storage costs and should not have toxic conservation systems applied to them. Both induce extra costs and make the business case of donor steel less competitive with new steel. In the future, currently suggested emission taxes do not affect the business-case significantly as these taxes are low compared to the total building costs. The most helpful action to increase the business-case is to apply donor steel more often. If the experience with donor steel and its availability grows, reuse will become easier. Steel-IT can contribute to this as it contributes to closing the knowledge gap on costs and impact and can help to match demand and supply.

The buildings construction industry is demanded to reduce its ecological footprint to mitigate its contribution to climate change. In this context, a novel sustainable design strategy for the reuse of timber was developed in this Master thesis. The design strategy focuses on the utilization of the material “reclaimed timber” (RT) in the structural system “reciprocal frame” (RF). RT is timber which is harvested from the load bearing structure of dismantled buildings. Large quantities of RT are currently fixed in the building stock. RFs are a family of structures that boast with a rich variety of forms and diverse functions. The utilization of RT in RFs is favorable because RT items which are relatively short can span distances longer than their length when combined with RFs. To inform the development of the design strategy a literature review on both RT and RFs was conducted. These theoretical studies were supplemented with more practical methods of investigation: RT was inspected first-hand during a visit of a salvage yard that stores RT. Throughout the project physical modeling was used as tool to explore and illustrate the characteristics of RFs. Moreover, during a three-day workshop in which a RF canopy structure from RT was built, important design aspects of RFs were investigated. This first part of the research concluded with describing the state-of-the art of the structural utilization of RT and providing a comprehensive overview of the structural design with RFs. Key findings of the theoretical and practical studies on both RT and RFs were that the limited stock of available RT items and the geometric complexity of RFs are the two major problems when designing a RF with RT. To solve the two problems a novel RT database configuration that archives the properties of specific RT items was developed. This RT database was applied in conjunction with a novel bottom-up geometry generation model for Rainbow RFs. The Rainbow RF was identified as advantageous for the combination with RT. It can be used to generate expressive spatial assemblies with a relatively low geometric complexity and a high degree of regularity. From a structural perspective the Rainbow RF has the benefit of efficiently transferring axial forces, which reduces the bending action that is typical for RF. Moreover, it achieves flexural rigidity without using expensive moment resistant joints. The key findings were integrated to form a preliminary design strategy. In a case study the preliminary strategy was used to design a RT RF for a railway station canopy that spans an area of 14.0 m x 27.0 m. The RT stock of the case study was defined by a database that is comprised of 30 stacks of RT items. Based on the material stock 118 geometric design proposals were generated using the bottom-up model. Three of the proposals were developed into safe structural designs. The three safe structural designs demonstrate that the RT items compensate their low strength grade with their relatively large cross-sections. Based on a discussion of the case study’s design process, a complete design strategy for the structural utilization of RT in RF structures is derived. In the first design phase the shape of the building and the flow of forces through the structure are established. The material stock is defined using the novel RT database configuration. For each RT stack multiple geometric design proposals are developed with the bottom-up model in design phase 3. The bottom-up model is set up in “Grasshopper 3D” and “Python”. For the fourth phase, a versatile algorithm is programmed that automates the structural design to a large degree. This enables to assess many geometric design proposals with considerable accuracy in a short time. The Structural Design concludes with a complete design of the RF structure. The structural design algorithm is also programmed in Grasshopper 3D and Python, the plug-in “Karamba3D” is used for finite-element analyses. The Detail Design rounds the design strategy off by detailing the structure’s joints.

The transverse stability of timber terraced houses can be provided by CLT stability walls where decoupled timber terraced houses are preferred to meet acoustic requirements leading to rather large thicknesses for the CLT stability walls and many large connections for anchorage to the foundation. The main goal of this research was to investigate the transverse stability behaviour of timber terraced houses, using a case study provided by WSP. Models to assess the transverse stability of timber terraced houses are simple schematizations with hand calculations of the decoupled and coupled timber terraced houses and FE models of decoupled timber terraced houses with and without T-section and coupled timber terraced houses with and without T-section. The coupling of the houses can be achieved by 4 Straviwood Modulink 6.0 kN connections per floor level. The T-section can be realised with double screws with diameter 𝑑 = 12 𝑚𝑚 with a spacing of 𝑠 = 100 𝑚𝑚. Simple schematizations with hand calculations of the decoupled and coupled timber terraced houses result in overdimensioning of the connections since bending of the floors due to deformation of the stability wall, providing resistance to the deformation of the stability wall, is not considered. This resulted in 6 hold downs per CLT stability wall. Compared to the FE model of decoupled timber terraced houses without T-section, all FE models have a positive influence on the design of connections in terms of reduction of number of hold downs and improvement of the total tension support reaction. Coupling of the houses is better compared to application of a T-section for decoupled houses. An improvement of the total tension support reaction of 83% and 67% for respectively the house on the left and the house on the right, compared to the decoupled timber terraced houses without T-section, can be achieved by coupled timber terraced houses with T-section. This also resulted in a reduction of 5 hold downs per CLT stability wall and the possibility to reduce the thickness of the CLT stability wall.

Glass is gaining more and more popularity as a structural material and has become a big share of the building industry. Unfortunately, the building industry is the largest polluter in terms of industrial waste and is responsible for 40% of Europe’s energy demand (CIB, 1999), and glass is also playing a significant role in this number. One strategy to reduce the amount of pollution from a product or industry is by making it circular (PBL, 2019). Meaning the amount of waste is minimized and the energy needed to produce new material is also decreased. In the Netherlands, buildings have to be completely circular from 2050 (Rijksoverheid, 2016). In order for glass to contribute to this goal, elements have to be able to be reused or recycled, taking demountability into account during the design of a structure. One way of creating such a demountable joint, is by making use of portal frames, which require a rigid connection between the columns and beams. Currently, this connection is designed using either mechanical connections or adhesives. Rigid mechanical connections are visually not aesthetically pleasing and cause impurities right at the points where stresses are highest. This makes the joint more sensitive to failure. Rigid adhesive connections are very prone to execution and design errors, and are uncertain regarding their long-term strength. Currently, there is no efficient way to properly remove adhesives, making them non-demountable joints. This research will therefore design a demountable and rigid joint using contact pressure, taking inspiration from traditional Japanese joinery. To develop this joint, first, theory is studied, followed by the design and lastly by experimental testing. From literature, the Kanawa and Gooseneck joints are selected, because they have the capacity to take up both shear and a bending moment. These joints are then further optimized to determine the optimal geometry for a rigid glass joint. This means a geometry that minimizes tensile stresses in the glass, decreasing the chance an existing flaw will tear and cause the material to fail. This optimization is done using analytical and numerical analyses, followed by full-scale experiments. To determine the optimal force transfer the geometries were first schematized, and the relevant parameters were determined for later variation. From hand calculations, it follows that the optimal geometry finds a balance between the stresses resulting from normal force and the stresses resulting from the eccentricity of the internal line of force. Using a parametric Grasshopper model, the geometries are further optimized by varying dimensions and curvature. Several designs are imported into DIANA FEA and Abaqus to acquire numerical values for the expected stresses of these set parameters. The models are set up as two 2D glass panes with a polymer interlayer in between them. In DIANA FEA a lot of difficulties arose with the combination of complex geometry and multiple contact surfaces. Therefore all designs were mitigated to Abaqus, because this software is more suitable for complex contact surfaces. Comparing the heavily simplified hand calculations to the FEA, there was a constant increase of peak stresses with a factor of 4. The Gooseneck design was manufactured using a CNC milling machine and afterwards, its edge was polished, resulting in optimal edge quality. Due to the nature of the geometry, the Kanawa design had to be manufactured using a waterjet. There was a large difference between the accuracy of the two production methods, resulting in the Kanawa joint having a lot more space between the glass plates. This strongly influences the placement of the interlayer materials, but also the stiffness of the joint during the experiments. Before these models could be validated using experiments, a suitable interlayer to place between the edges of the glass panes was researched. POM, PVC, Surlyn, PA6 and PU85 are deemed suitable and are examined. Eventually, only PU85 could be fitted between the glass panes, which seemed to have the least favourable mechanical properties. The angle of the geometry was too small for most materials to bend them into, even after heating the plastics. The other issue lay with the tight tolerances of the polished glass panes. These had to be additionally polished by hand and the PU85 was treated with silicone spray, in order for the whole joint to fit. The disadvantage was that this manual polishing damaged the edge quality, increasing the probability of failure at a lower strength. Experiments were then conducted to validate earlier analytical and numerical calculations, using full-scale single-pane annealed glass. The joints were tested in pure tension and a bending moment, using polarizing filters to visualize the stress trajectories. For the Gooseneck model, the stress trajectories and expected stiffness corresponded well with the models. The samples failed at an average force of 6.0 kN. The model predicted peak stresses of 300 N/mm2 and stiffness of 2.8 N/m at this point, the experiments displayed a stiffness of 3.0 N/m. This means the model turned out to be 5.7% less stiff than the experiments. The stress trajectories coincided less clearly with the model for the Kanawa tension model. The samples failed at an average force of 4.1 kN. The expected peak stresses at this point were 150 N/mm2 and the stiffness 0.73 N/m based on the model. The experiments showed a stiffness of 1.1 N/m. The model underestimates the stiffness of the experiments by 33%. Interestingly, because the tolerances in the Kanawa joint were larger, there was more movement possible in this joint. This influenced the force transfer and therefore resulted in different peak stresses than expected. The Gooseneck model turned out to be almost 3 times as stiff as the Kanawa model. This has two likely reasons. First of all, the geometry of the Kanawa joint is not designed to take up pure tension in the direction that it was tested. Therefore, the geometry itself was a lot less stiff than that of the Gooseneck joint. Secondly, the tolerances were of large influence. Because the Kanawa samples were produced using a waterjet, with quite large tolerances, there was a lot of movement possible in the joint. This meant little force was necessary to displace the joint, resulting in a lower stiffness. The Kanawa design was tested under a bending moment, because the force transfer is very different compared to pure tension for this design. The full beam had dimensions of 2400mmx 400mmx 10 mm. Locations of peak stresses were similar to the models. The samples failed at an average of 4.0 kN, which corresponds with a moment of 1.1 kNm. The force-displacement graph of the experiments was not linear, but showed varying stiffness with plateaus where the stiffness was around 0. Most likely, this was caused by a combination of the plastic deformation of the PU85 and movement and/or sliding in the machine itself. It was attempted to calibrate the model to the experiments, by increasing the stiffness of the interlayer. This did not result in sufficient stiffness, which implies the stiffness originates from another element in the setup. The rotational stiffness was 611 kNm/rad, which is 9.1% of the stiffness compared to a solid beam of the same dimensions. This means the designed joint is not fully rigid, but this exploratory study shows there is great potential for such a system. Further optimizing the geometry and finding a more suitable interlayer could result in a rigid and demountable glass joint, as part of a portal frame.

The aim of this research is to make the early design process more efficient. This is done with a parametric model, which compares high-rise stability systems. The research is focused on the stability systems shear walls, core, outrigger and tube. All systems are executed in concrete cast-in-situ, in the range from 100 to 250 m. The parametric model is executed in Grasshopper and Karamba. Four performance criteria are checked in the model. These are strength, stiffness, foundation design and comfort. An optimisation procedure has been applied to find the most optimal system based on input and optimisation goal. Three optimisation goals have been appointed. These are slenderness of wall and column elements, total weight and carbon emission and flexibility. Flexibility is defined as effective floor area and ratio facade openings. The results of each optimisation goal are plotted with respect to the height to obtain insight in the suitability per system. Input parameters, optimisation procedure and performance criteria have been processed in a tool in Human UI. The model and tool have been applied on De Zalmhaventoren to verify the outcomes. It can be concluded that the model, tool and optimisation results have led to more insight in the high-rise early design process and ease decision making.

Currently, the building industry contributes to up to 50% of climate change. A way to reduce the impact is by replacing current building materials with more environmentally friendly materials, such as timber. Engineered wood products, such as cross-laminated timber (CLT) panels, have increased strength, stiffness, and stability which enables building higher buildings and floors with bigger spans. However, due to the low weight of timber, CLT floors are susceptible to unwanted high floor vibrations and therefore need to be verified on their footfall-induced vibration performance. Predicting the vibration performance is a complex problem as the load-bearing structure and architectural finishing have distinct structural behavior under small vibrations. Due to the novelty of the problem, the distinct behavior is not captured well in the current design codes. As a result, the Eurocode 5 guidelines on vibrations are currently being updated and extended. In support, this thesis addresses the critical issue of predicting the vibration performance of CLT floors, with a specific focus on the impact of architectural finishing. To achieve this goal, a literature review was conducted to identify structural components that are often overlooked, but may lead to inaccuracies in vibration predictions. These factors include the connections between CLT panels and different types of floor finishing. A case study was then carried out using the building HOUTlab, which features CLT floors with a concrete floating screed. On-site measurements were performed at key locations, including at the inter-panel connection line and in the middle of the panel. This was done before and after architectural finishing was placed. Subsequently, analytical and numerical calculations were used to gain insight into the structural behavior of the system subject to footfall-loading by investigating the accuracy of common engineering practices and other assumptions regarding their structural behavior. Onsite measurements, where the floor was loaded and the response was measured at the same location, showed that the root mean square velocity (vrms) values were much higher at the inter-panel connection line compared to in the middle of the panel. The vrms is a measure of the amplitude of the vibration. The initial finite element analysis (FEA), assuming a rigid inter-panel connection, inaccurately located the highest vrms values. When assuming a hinge, the FEA correctly allocated the critical vrms values but compromised the accuracy of frequency estimates. The experimental results revealed that adding architectural finishing increased the damping, reduced the vrms, and maintained a similar frequency, ultimately improving the vibration performance from level 3 to level 1 according to the preliminary Eurocode 5 (prEC5) standards. The prEC5 and FEA following common engineering practices accurately estimated the frequency before architectural finishing was placed but underestimated it by 39% after it was placed, indicating a higher increase in the bending stiffness of the floor than initially assumed. While prior calculations assumed slip between the floor layers due to the presence of the insulation layer, assuming full cooperation between the layers resulted in an overestimation of the frequency by 9%, suggesting that there is some cooperation, but the floors are not fully bonded...

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.

On April 15th, 2019 a devastating fire burned down Notre Dame de Paris and left the cathedral without its central spire and ancient gable roof, better known as The Forest. The required reconstruction initiated a global debate between architects, engineers, and other stakeholders. The discussion was put to an end by the French authorities, who proposed an identical reconstruction within a timeframe of 5 years. The decision forced the construction crew into a difficult job of finding identical construction materials, eventually leading to environmental and humanitarian suffering in Ghana, where a tropical underwater forest was felled. Besides, the time pressure put the quality of the reconstruction at risk. In the presented thesis, an alternative design for Notre Dame’s roof is proposed. First, the authorities’ reconstruction plans are analyzed to see which practical challenges will have to be tackled. An alternative reconstruction strategy is then developed for the choir and nave of the cathedral. Inspiration is drawn from Notre Dame’s initial construction in the 12th and 13th centuries, during which time pressure also played a key role in the design. The Master Builders’ clever construction strategies like integrated support structures and utilization during construction are indispensable parts of Gothic engineering and are used to tackle current problems. The proposed alternative construction process consists out of three phases: Fast Fix, Field Factory, and Former Finishing. The resulting structure, The Timber Skeleton – named after Professor Jacques Heyman’s book: The Stone Skeleton -, consists out of stabilizing cassettes (Fast Fix), expandable roof segments (Field Factory), covered by a roof cladding with the same external appearance as before the fire (Former Finishing). Notre Dame’s attic is imagined to function as a publicly accessible workshop, dedicated to the constant maintenance of the cathedral and all its Gothic ornamentation. As an alternative to the difficulties the authorities are facing in finding proper timber, modern construction materials and prefabrication strategies are investigated. They are utilized to facilitate a relatively quick construction without obstructing other on-site restoration works. Laminated veneer lumber with cross-plies is used to design openworked members with structural expression. For the particular geometry of the rafters, the boundaries of current analytical engineering tools have been explored. Different verification strategies have been assessed and compared to analyze the structural functioning and feasibility of The Timber Skeleton. A conventional stress analysis is eventually used for the structural verifications of The Timber Skeleton and its most important joints. Recommendations are given for further development of the design, in which mainly the moment rigid connections of the rafters will require numerical and physical testing. A Master Builder’s mentality of prototyping and trial and error will be needed to realize the proposed design. The research shows how an alternative reconstruction strategy for Notre Dame de Paris could result in a good functioning structural design that pays homage to Gothic engineering principles. The design functions as an innovative example for how modern production processes could help to arrive at a contemporary interpretation of The Forest that functionally and structurally better fulfills the contemporary requirements.

Glass has become ever more popular in the building industry. Glass is already used in facades, staircases, fins, floors, and beams. Nevertheless, free-standing load-bearing glass columns are rarely used. It needs to be robust, which means that it needs to give a warning before failure so that people can evacuate. Glass is a brittle material and has a sudden failure, which means that it is not directly logical to use solid glass as a load-bearing structural column. Rather despite the high compressive strength, due to complications with manufacturing, spontaneous failure, and lack of satisfactory of fireproof performance, more research needs to be done on the manufacturing, the fire safety, and the robustness of glass columns. In the literature study, the layered tubular glass column was found to be most promising for further investigating. The aim of this research is to design and engineer a transparent tubular glass column as a structural element, which is robust and fireproof. In the literature study a few aspects emerged: the tubular shape, the column needs to be sealed to avoid the column from becoming dirty, end connections, the geometric tolerances in the glass tubes and the robustness. The designs were engineered for the case study Bouwdeel D in Delft, but the designs can also be applied to other buildings: the fire resistance, demountability, the dimensions and the calculated compression loads. With these aspects in mind, three designs were engineered, the MLA (Multi Layered with Air) (2x) and the SLW (Single Layered with water) (1x) which fulfil the defined design criteria/main concerns. Six small samples with a length of 300 mm were produced to test the lamination process with regard to bubble formation and possible breakage of the glass by internal stresses. Three laminated DURAN (annealed) samples and three laminated DURATAN (heat-strengthened) samples were tested. The glass tubes were manufactured by extruding and were made by SCHOTT. H.B.Fuller Kӧmmerling carried out the lamination process. Furthermore, the connection components (steel and POM) were produced and arranged by Octatube, the steel hinges were arranged by Techniparts, and the Hilti mortar was arranged by Hilti. Afterwards, these samples were tested on compression strength, to investigate the behaviour of the interlayer material, the post-failure behaviour of the designs, the differences between annealed and heat-strengthened glass samples, the behaviour of the connections under pressure, and the capacity of the glass tubes and the connections. The first cracks appeared earlier than expected. Nevertheless, the samples seemed to be really robust, because the samples had a large load-bearing capacity even after the first cracks occurred. The first crack appeared between 95-160 kN in the DURAN samples, and after that the samples were still able to carry a load of 700-750 kN. So, after the first crack, the specimens were able to have around 4-5 times more load. The heat-strengthened samples first cracked at 120-160 kN. The maximum force of these samples was 390-490 kN. This means that after the first crack, the specimens were able to have around 3 times more load.

This research tries to answer the question which construction material, concrete or timber, is best to use during the construction of terraced housing in the Netherlands, based on the environmental performance. Existing studies often do not take all aspects of a design for the comparison into account, or have a bias toward one material. In order to investigate the main research question, a literature study has been executed together with a practical case study.

Gas extractions are responsible for mostly all induced earthquakes in the Groningen area and this leads to damage of houses and buildings and issues regarding safety. Current strengthening measurements are mostly very visible. However, this can change by using the window frame as part of the structure, particularly interesting for Dutch houses characterized by large window openings. In this thesis, the focus is on the validation of the numerical model based on experimental testing. From this, the main research question was formulated as “How can the structural window frame be modelled to agree with the experimental results, in order to assess the seismic performance for unreinforced masonry structures?”. The structural window frame is made of a timber frame, an adhesive and a double-glazing unit. The timber frame is made of hardwood on the outside and plywood on the inside. The potential of the structural window frame is researched into several numerical, experimental and design studies using DIANA 10.4. It is concluded that a specific non-linear elastic interface model for the adhesive is the best suitable model. This numerical model is used as a loading protocol for the experiments. The structural window frames have been built and tested at the TU Delft. The experimental results showed that the structural window frame behaves plastically. Concluding, the glass panels and the hardwood are not damaged however, the plywood is pinched due to the glass panel. The numerical model is adjusted to include the pinching behaviour of the inner bar to suit the experiments. The next step is the masonry model. The masonry model including the structural window frame showed an increase of 15% for the in-plane shear force capacity and a decrease of 23% for the crack width for a displacement of 4 mm, compared to the unstrengthened masonry wall. The pushover calculation showed that both the unstrengthened and strengthened masonry wall can withstand the seismic loads in Appingedam. According to assumptions, the structural window frame results in an increase of the shear force capacity of 47% for larger displacements. The ductility of the structure can be increased by increasing the effective mass to 15000 kg. However, the calculation is only valid for the assumed values, these results should not be taken too strictly. The design of the window frame can be improved by using: a stiffer timber frame, a thinner adhesive and a more sustainable design. Using a frame that is twice as stiff and strong has resulted in: similar initial behaviour, higher maximum shear force and later stabilisation of the in-plane shear force. Using a thinner adhesive than 5 mm does not result in more beneficial results. Furthermore, making only screwed connections and maintaining the structural window frame frequently could increase the lifespan of the structural window frame. The structural window frame has potential however, more numerical and experimental research should be done.

There are two main challenges in the construction industry: carbon emissions and densification in cities. Timber high-rise might prove as a suitable solution to both these challenges. However, there is a lack of implementation of timber high-rise. This research argues that a lack of thorough analysis of timber design alternatives in the conceptual design phase results in the exclusion of further evaluation of timber building designs. This research aims to analyze timber building design alternatives more thoroughly by the development of a tool, based on the Multidisciplinary Design Optimization (MDO) method. In Grasshopper, a parametric model is created with which timber building designs are generated, validated, and optimized. Two main optimization objectives and two constraints are considered in the tool: Firstly, the structural constraint: Each building must be designed according to the constraints as determined in the Eurocode. Secondly, the architectural constraint: Each building must satisfy the architectural design requirements for acoustics, building height, and daylight entrance. Thirdly. the environmental objective: minimize the shadow costs, which are determined according to the MPG methodology. The MPG methodology uses Life Cycle Analysis data to assess the embodied energy impact of structural materials. This embodied energy impact is expressed in shadow costs. Lastly, the economical objective: minimize the construction costs. Based on the mentioned constraints, the tool aims to indicate the design situations in which timber high-rise can be competitive to an assessed concrete design alternative, considering the combination of properties for shadow costs and construction costs. By research and development of the Multidisciplinary Design Optimization tool and analyzing two case studies, a conclusion can be made. Two concrete buildings, which are based on a current Arcadis project, are used as case studies. Both concrete buildings represent a design situation. The main difference between these design situations is the building dimensions. Building A3 represents timber building designs that are created for a design situation with a floor area of 28.8 x 28.8 m and a height of 60 meters. Building B3 represents timber building designs that are created for a design situation with a floor area of 21.6 x 43.2 m and a height of 50 meters. For both case studies, an optimization will obtain timber building designs with an optimal combination of properties for shadow costs and construction costs. This resulted in the following results. For the design situation based on the concrete building "The Rectangle", the Pareto optimal timber building designs, referred to as Building B3, were found to be competitive with "The Rectangle". For the other analyzed design situation, the Pareto optimal timber building designs referred to as Building A3, were not found to be competitive with the concrete building "The Square". Considering the boundary conditions and scope of this research, it can be concluded that a design situation with a rectangular floor plan is favorable over a design situation with a square floor plan and a design situation with a building height of 50 meter is favorable over a design situation with a building height of 60 meter. Also, based on analysis of the case studies the following conclusions were made. Firstly, when the effect of carbon sequestration is excluded in the calculation of shadow costs, the use of timber and concrete in the structural system was found to generate comparable results considering their shadow costs. The inclusion of the effect of carbon sequestration during the lifetime of a timber building results in a reduction of shadow costs of approximately 40% compared to a similar concrete building. Secondly, considering the boundary conditions and scope of this research the ULS is found to be normative for a slenderness up to 2.35. When the slenderness is greater than 2.35, the along-wind acceleration was found to become normative. Next, for all Pareto optimal building designs, the ULS check was found to be normative over the SLS check. Lastly, the mass of the Pareto optimal timber building designs was found to be approximately 8 times smaller than their respective concrete design alternatives, resulting in a foundation with less construction costs and shadow costs.

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.

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.

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.

This research investigates how to design a glass pedestrian bridge that is structurally optimised for multiple load scenario’s and feasible in terms of fabrication and construction. Linear glass elements such as panes have limited freedom of shape. On the other hand, cast glass can be produced into any shape possible. When glass is used in large quantities with large cross-sections, the annealing process can take a long time and require a significant amount of energy. The annealing time must be kept to a minimum to make cast glass a viable option. This is where topology optimisation can play its part. During topology optimisation, the layout of an element is optimised on the given constraints for the specified design domain. A compliance-based optimisation is found to be the most suitable objective function. The software package Ansys and various plugins for McNeel Rhinoceros/Grasshopper are compared on their topology optimisation tool. During this comparison, Ansys is found to be the most suitable software. This is mainly because of the possibility of implementing a cross-sectional constraint during the optimisation, which is needed for implementing a maximum annealing time. The most suitable production method for topology optimised cast glass elements is found to be kiln casting with a 3D printed sand mould. Glass is a brittle material with a low tensile strength compared to its compressive strength. The only type of bridge that can be made entirely in compression, without pre-tensioning, is an arch bridge. This bridge type is used for the final design. The loads considered during structural analysis are the vertical traffic load (distributed and point) and the vertical wind load. The bridge is made from borosilicate glass. This type of glass is used to reduce the effect of temperature on the cast structure of the bridge. Additionally, the supports and connections are designed so that they do not restrain deformation from temperature. Furthermore, the shape and place of the connections and supports ensure the possibility of unequal settlement without the formation of unacceptable stresses. Multiple variant studies are carried out. In the first variant study, optimisation is done on several 2D models to determine the best shape for the bridge's final design. The second variant study focuses on the 3D shape of the bridge and how the bridge is split into manageable segments. The final bridge comprises four cast outer elements, one cast keystone, and a float glass bridge deck. The bridge is simply supported on both sides of the canal. The connections and supports are based on compression and friction and use a polyurethane interlayer. The weight of the final optimised bridge is reduced from 32t to 11.2t with a maximum cross-sectional thickness of 210 mm to get an annealing time of approximately one month. Due to symmetry in the design, only one-fourth of the bridge is optimised. During the optimisation, seven different distributed load scenarios are implemented. For the point load, a region is excluded from optimisation. After optimisation, finite element analysis and manual verifications are performed.

Glass is a fascinating material that has also been used as a primary construction material in various remarkable buildings since the last century. Unfortunately, a lot of carbon dioxide is released during the production of glass because of the extreme heat required. The construction industry accounts for ten per cent of global CO2 emissions. If a focus in this sector is put on recycling, reducing and reusing, emissions can be drastically reduced because of less needed new building material. However, structural glass is currently hardly reused. A second challenge arises with existing demountable structures made of glass like the LocHal: these are not weatherproof, thus unsuitable as sheltered accommodation. In response to the absence of adequate standardised structural glass building systems, this research project proposes a preliminary design for a modular, transportable art pavilion with an appropriate structural verification. The research question is therefore: ’How can glass be applied as load‐bearing material in temporary modular building units to realise easy‐to‐ (dis)assemble, transparent and transportable structures?’. A case‐study is introduced to find an answer to the main research question. The fictive scenario is sketched to design a temporary art pavilion which stands for one to three months in a city centre in the Netherlands. After this period, the pavilion should be demounted and transported to the next destination. The information described here determines the boundary conditions for the design and calculations. The imaginary pavilion is 24 m in length, 10 m in width and 2.5 m in height. The inner walls in the pavilion are retained to create a natural walking path inside. On the short side of the pavilion, doors are inserted as an entrance and an exit. From the available literature, the transportability of the building elements and the requirement for thermal insulation appear to be important preconditions for the final design. The design is based on four different types of prefabricated building elements: roof panels, wall panels, floor panels and base profiles. The roof panels are of 220 mm thick cross‐laminated timber (CLT), in length six or three metres and have a width of 2.5 m. The wall panels are of laminated glass, 2.5 m in height and come in two types. Insulated glass units (IGU’s) of 6 or 5 m long function as exterior walls. These consist of an outer sheet of 10 mm fully tempered glass, a 15 mm cavity of 90% argon gas and a triple laminated inner panel of 5.10.5 mm heat‐strengthened glass. The inner walls are of a composition of 5.10.5 mm heat‐strengthened glass. The glass is laminated with a SentryGlas® interlayer of 1.52 mm. CLT is also used for the floor panels, now with a thickness of 210 mm and lengths of 6 and 3 m. The base is defined by steel ’cap’ (RHSFB, lengths of 6 and 5 m) and ’hat’ (THQ, length of 4.25 m) profiles. Both profiles are 265 mm in height. Roof connections, wall connections and base connections were designed and dimensioned, in total seven different types. The most innovative and structurally interesting joints are two wall connections. These connections consist of a so‐called ’coffee‐ cup‐hand’ system; titanium elements laminated 30 mm into the middle sheet of the wall panels. The wall panels are checked on maximum deflection and tensile stress, as well as the local tensile stress in the glass and in the SentryGlas® interlayer around the laminated titanium elements. All checks comply with the maximum allowable values described in the Eurocodes and in literature. The conclusion is that the proposed design, with some enhancements to be made, satisfies the structural‐, building physics‐ and practical requirements as a transportable and a relative transparent building system for structural glass. With this building system, glass can be integrated as a load‐bearing material for designs of temporary structures. Engineers who wish to apply this building system in practice are advised to first enhance the roof connections. For transportation means, the grid‐measurements should be decreased by 8% to fit the components in a regular container. For practice, it is also advised to deal with factors such as installations and drainage systems, which were not included in this study. Follow‐up research could focus on the adaptability of the building system when the building is used with a more permanent function. In addition, it is mechanically interesting to further investigate how the wall connections interact with each other in a 3D analysis and lab experiments.