This article presents the metric avoided carbon for the reuse of aluminium unitised curtain wall façades, that are to be taken from a donor building an applied onto a receiving building. The metric is used to compare seven proposed circular reuse strategies, each showing a different level of reuse. Based on literature and reference studies, we identify those parts of the façade where reuse has the most impact and is technically feasible. The seven reuse strategies and the avoided carbon method are applied on a real case study building as donor project and a fictitious building as receiving project. We conclude that reuse is technically feasible, saves carbon, and that the proposed metric can help to incentivize building owners and project developers to adopt circular reuse.@en

Smart buildings are equipped with automated control systems that provide a comfortable indoor environment, aiming simultaneously at energy savings. Control systems for shading devices applied in practice are mostly driven by a rule-based approach, that is usually tested under simplified conditions and hence its effectiveness in complex real-life cases is questionable. The present study develops an optimized glare-based control strategy for Venetian blinds in a real-life open-space building with totally transparent facades. The research is based on the case study of the Co-Creation Center at the TU Delft campus, which can host three different types of events: presentations, meetings and workshops. The control strategy is developed within Grasshopper, a tool for parametric and optimization problems. Radial Basis Function Optimization (RBFOpt) is utilized for the computation of the optimal blinds’ states. Within the developed control strategy, cylindrical illuminance (Ecyl) is used as a glare index, giving the opportunity to evaluate its performance. Results show that the optimized algorithm can improve the existing visual conditions in the building by an average of 80% for all activity types, although it leads to an average increase of 7% of the time when electric lighting is needed, in comparison to the current rule-based control. Finally, Ecyl displayed an overall agreement of 92.5% with DGP-based glare assessments, proving that in spaces with multiple windows and uncertain occupants’ view direction, a view-independent index can predict glare risks as well as a state-of-the-art view-dependent metric.@en

This Jupyter Book aims to provide students with easy access to an overview of prerequisite knowledge needed to successfully start the MSc degree Civil Engineering at TU Delft. Students can check themselves whether they have the necessary prior knowledge, and estimate which subjects they may need to repair or refresh before coming to TU Delft. The Jupyter Book was made in the educationalal research project called PRE-for-CEM (PRErequisite knowledge for Civil Engineering Master) during 2022 and 2023. The project was funded by TU Delft Open Education Fund and the Educational Management Team of the Faculty of Civil Engineering and Geosciences.@en

In the Netherlands, the potential damage to the building stock due to subsidence phenomena has recently received increased awareness. However, evaluating and predicting damage to buildings in subsiding areas is a complex task that requires associating the vulnerability of exposed structures with the intensity of the subsidence hazard. Considering the widespread presence of subsidence-related damage to the built heritage, the focus of this study is to provide empirical-based insights to assess and forecast subsidence damage to masonry buildings. A rich dataset with manual levelling measurements was collected comprising 386 surveyed masonry buildings, mainly low-rise (terraced) houses built before 1950. Of the total set of buildings, 122 cases rest on shallow foundations and 264 on piled foundations. For each building, the recorded damage is related to the settlement, calculated from the bed-joint levelling measurements, using four different intensity parameters, namely differential settlement, rotation, relative rotation and deflection ratio. These four parameters are appraised in their capacity to effectively predict the intensity of the damage. The Receiver Operating Characteristic (ROC) method is used to evaluate the relative efficacy of the selected hazard parameters. The rotation, the relative rotation (angular distortion) and the deflection ratio are observed as the most accurate when predicting the intensity of damage, while the differential settlement appears less accurate. Additionally, the dataset was used to generate empirical fragility curves where the probability of damage is described as a function of the aforementioned parameters. Thresholds were set to distinguish between the light damage and the functional and structural damage state. At a relative rotation of 1/500 masonry buildings on shallow foundations were observed to reach or exceed light damage with a probability of 13%, and functional and structural damage with 5%. The availability of the bed joint levelling measurements made it possible to classify eight recurrent settlement profiles, including both symmetric and asymmetric profiles, associated with both the overall deformation and the rigid rotations of the surveyed buildings.@en

Wat te doen als je prachtige gekromde glazen gevel onverwacht als vergrootglas blijkt te werken? Het fenomeen, dat al enigszins bekend was van de beruchte “Walkie Talkie” in Londen, is al eens eerder beschreven in Bouwfysica in 2018 [1]. Helaas kon dat artikel niet voorkomen dat ook in Nederland dit probleem vorig najaar plotseling optrad bij een nieuw gebouw dat op het punt stond opgeleverd te worden. Smeltende auto-onderdelen op het ondergelegen parkeerterrein, mogelijk gevaar voor bezoekers en een ongeruste opdrachtgever waren het resultaat. Parametrische tools en software voor simulatie van bezonning hielpen het ontwerpteam en de opdrachtgever om samen te zoeken naar de meest geschikte oplossing.@en

The form freedom enabled by digital fabrication with concrete technologies provides advantages for a wide range of concrete based objects, from architectural to structural elements. The current chapter focuses on the specifics of structural design and engineering of DFC with emphasis on those technologies based on Additive Manufacturing with extrusion. Since it is a new and innovative way to build, a clear common approach to structural engineering has not yet been developed. As a result, this chapter aims to introduce the specific challenges of structural design and engineering with the additive manufacturing technology, providing an overview of structural typologies that have been developed (especially concerning the reinforcement strategies, including fibre reinforcement). Furthermore, the structural principles adopted in DFC and the codified approaches used in conventional reinforced concrete is compared, and putative structural testing procedures and validation methods for DFC are reported.@en

Low Temperature Heating (LTH) of buildings is a key feature when switching to renewable energy. Even when the capacity of LTH is high enough, LTH may adversely affect indoor thermal comfort in case buildings are not suitably insulated. This paper goes deeper into methodological issues when conducting a thermal comfort assessment. Thermal comfort is either quantified by Fanger’s Predicted Mean Vote (PMV) or ranked in building comfort classes in the adaptive model. In both cases, one of the main parameters influencing comfort is the Mean Radiant Temperature (MRT). This study addresses issues with common MRT and PMV calculations in energy simulation software. The case study is TRNSYS 17. Several MRT and PMV calculation methods are compared, showing possible draw-backs and deviations from comfort standards NEN-EN ISO 7726 and 7730. For instance, in the standard heating settings in TRNBuild only the total heating capacity is specified. The radiative part is then distributed area-weighted over opaque surfaces. A more detailed option in TRNBuild is to specify the locations of radiative gains as points. In both cases, the MRT at a comfort sphere is calculated with Gebhardt-factors instead of view-factors. The standard settings may be considered too simplified for detailed comfort studies whereas the detailed model shows deviations from comfort standards NEN-EN ISO 7726 and 7730. Therefore, two additions to these models are proposed to increase accuracy. One addition is an ordinary detailed model with radiative gains as point sources in order to retrieve all surface temperatures during a desired period of time. In the second addition walls with radiators are split-up and planes are added at the locations of radiators to generate a view-factor matrix. This can be done in TRNBuild, but also in other view-factor calculation software. From model 1 all surface temperatures are retrieved. Combined with the view-factors from model 2, the MRT can be calculated.@en

The need for methods for forming concrete has existed for as long as concrete has been used in constructing the built environment. Creating flat, rectilinear formers have traditionally been the cost and time efficient default for the majority of applications. The desire for greater design freedom and the drive to automate construction manufacturing is providing a platform for the continued development of a family of processes called Digital Fabrication with Concrete (DFC) technologies. DFC technologies are many and varied. Much of the material science theory is common, but the process steps vary significantly between methods, creating challenges as we look towards performance comparison and standardisation. Presented here is a framework to help identify and describe process differences and a showcase of DFC application case studies that explain the processes behind a sub-set of the technologies available.@en

Unitized curtain walls are glazing facade systems widely used in modern architecture for mid and high rise buildings, due to their benefits in terms of lightness, quality control, ease of construction and quick installation. However, recent earthquake surveys have shown damages to these non-structural elements. Slight-to-moderate damage can cause loss of facade functionality, moderate-to-major damage can provoke severe post-earthquake economic losses and pose a life-threatening danger to both building occupants and pedestrians. Despite recent studies on the seismic behavior of unitized curtain walls, research in this field is still limited and experimental investigations typically neglect the study of the overall facade performance as well as the identification of the full sequence of damage states and the ultimate resistance of the facade components. This paper presents the extensive experimental campaign carried out at the laboratory of Permasteelisa Group, in Vittorio Veneto (Italy), to investigate the seismic behaviour of full-scale unitized curtain walls from a holistic and multi-performance perspective. The research aims at providing information about the serviceability performance and the ultimate limit state of alternative facade designs. The tests involve various facade configurations consisting of dry (gasket) vs. wet (structural silicone) glazing systems with different construction details for glass, frame and joints (dimensions and type). The testing sequence consists of displacement-control dynamic cyclic loading and/or time histories at increasingly seismic intensity levels, accounting for in-plane, out-of-plane and vertical movements. Air infiltration tests, water leakage tests and wind resistance tests are performed before and after the low-intensity seismic tests to study the post-earthquake facade serviceability. This paper discusses the research objectives, the specimen details and the test setup, and provides preliminary experimental results.@en

Digital Fabrication with Concrete (DFC) encompasses 3D Concrete Printing (3DCP) and many other methods of production. DFC is emerging from an era of invention and demonstration to one where the merits of one principle over another needs to be quantified systematically. DFC technologies vary in characteristics, complexity and maturity which hampers the synthesis of research and comparisons of performance. The interdependence of design geometry, material properties and process characteristics is well recognised. Materials research has made significant progress in recent years and there have been many applications with varying design geometries demonstrated. Far less has been done to guide the definition and description of the processes used. This work takes a step forward by presenting classification and process description guidance for DFC. The approach was developed by engaging a broad cross-section of the international community through the activities of the RILEM Technical Committee 276 between 2016 and 2020.

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The transition period between the mixing of concrete and the begin of setting increasingly receives attention, as special production processes can be developed with tailor-made fresh state characteristics. In this publication the two processes of 3D Concrete Printing (3DCP) and the production with the Flexible Mould Process (FMP) are discussed and compared. The FMP is a relatively new manufacturing method that was developed to allow the efficient production of curved thin concrete panels for cladding or structural use. The term ‘flexible’ refers to the deformation into the required curved shape of both the compliant mould surface and the fresh concrete contained by the mould shortly after casting. After that deformation, both the mould and the concrete are left for further hardening until demoulding is possible. The development of the 3DCP technique progresses fast, hereby new perspectives are gained with regard to mix design, production and structural performance. Sideway, test methods need to be developed or re-evaluated. The early age strength and strain capacity are important parameters for both processes, although they are not the same with regard to magnitude, period or time after mixing. Both processes can be executed within an open window and with specific boundary conditions only. This publication discusses and compares both processes. The implications of these recent findings are translated to practical aspects with regard to the production with the FMP.

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Construction robots are becoming more common in the Netherlands, but remain rarities in contexts aside from state-of-the-art factories owned by wealthy or technologically-orientated companies. In its current state, the construction industry would have to change significantly to make room for robots. To understand whether these changes are welcome or not, this paper presents qualitative, exploratory research concerning 10 stakeholders’ perspectives of robotisation and construction robots in the Dutch construction industry.@en

This paper proposes a photogrammetric procedure able to determine out-of-plane movements experienced by a masonry structure subjected to a quasi-static cyclic test. The method tracks the movement of circular targets by means of a coarse-to-fine strategy. These targets were captured by means of a photogrammetric network, made up of four cameras optimized following the precepts of a zero-, first-, and second-order design. The centroid of each circular target was accurately detected for each image using the Hough transform, a sub-pixel edge detector based on the partial area effect, and a non-linear square optimization strategy. The three-dimensional (3D) coordinates of these targets were then computed through a photogrammetric bundle adjustment considering a self-calibration model of the camera. To validate the photogrammetric method, measurements were carried out in parallel to an ongoing test on a full-scale two-story unreinforced masonry structure (5.4 × 5.2 × 5.4-m) monitored with more than 200 contact sensors. The results provided by the contact sensors during one of the load phases were compared with those obtained by the proposed approach. According to this accuracy assessment, the method was able to determine the out-of-plane displacement during the quasi-static cyclic test with a sub-pixel accuracy of 0.58.@en

The exploitation of geo-resources in the northern part of the Netherlands (Groningen region) is triggering shallow earthquakes, rising the need of assessing the current building stock. Being the region not prone to tectonic earthquakes, buildings are designed as wind-resistant systems and have specific characteristics that can limit their seismic performance. In this framework, an extensive research has been carried out on the performance of low-rise unreinforced masonry (URM) buildings at Delft University of Technology. Major attention was focussed on the behaviour of terraced houses, which represent the majority of structures within the URM building stock. In this paper, the case study of a modern Dutch terraced house, built after 1980, made of calcium silicate element masonry and reinforced concrete floors is considered. A quasi-static cyclic test on a full-scale two-storey structure resembling the considered typology is presented. The experimental results are used to evaluate the seismic performance of the structure in the framework of the nonlinear static analyses. A comparative study highlights the importance of the selection of the assessment procedures. Adopting the experimental results as a benchmark, a blind prediction contest revealed a large output variability depending on the adopted analysis method and modelling choices. Consequently, the cross-validation among different analysis methods currently appears the best approach to achieve a more accurate prediction of the structural capacity. The combined experimental and numerical work presented in this paper allows gaining a deeper insight on the evaluation of the seismic performance of Dutch terraced houses.

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Vulnerability of buildings to natural and man-induced hazards has become a main concern for our society. Ensuring their serviceability, safety and sustainability is of vital importance and the main reason for setting up monitoring systems to detect damages at an early stage. In this work, a method is presented for detecting changes from laser scan data, where no registration between different epochs is needed. To show the potential of the method, a case study of a laboratory test carried out at the Stevin laboratory of Delft University of Technology was selected. The case study was a quasi-static cyclic pushover test on a two-story high unreinforced masonry structure designed to simulate damage evolution caused by cyclic loading. During the various phases, we analysed the behaviour of the masonry walls by monitoring the deformation of each masonry unit. First a plane is fitted to the selected wall point cloud, consisting of one single terrestrial laser scan, using Principal Component Analysis (PCA). Second, the segmentation of individual elements is performed. Then deformations with respect to this plane model, for each epoch and specific element, are determined by computing their corresponding rotation and cloud-to-plane distances. The validation of the changes detected within this approach is done by comparison with traditional deformation analysis based on co-registered TLS point clouds between two or more epochs of building measurements. Initial results show that the sketched methodology is indeed able to detect changes at the mm level while avoiding 3D point cloud registration, which is a main issue in computer vision and remote sensing.

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Innovatieve software komt regelmatig op de markt, maar Rhinoceros-Grasshopper heeft een compleet nieuwe wereld aan mogelijkheden ontsloten. Ook voor de bouwfysicus is dit zeer relevant. Doordat gebruik wordt gemaakt van een intuïtieve, parametrische en grafische programmeertaal, kunnen complexe geometrische problemen zeer snel worden gemodelleerd en opgelost. Dit artikel beschrijft een bouwfysisch probleem dat in de ontwerpfase al voorkomen had kunnen worden door het snel en effectief door te rekenen met deze tool. @en

In recent years induced seismicity in the Netherlands considerably increased. This phenomenon has a wide impact on the built environment, which is mainly composed by unreinforced masonry (URM) structures. These buildings were not designed for seismic loading, and present peculiar characteristics include very slender walls (100 mm thickness and 2.5m in height), limited connections between walls and floors, and use of cavity walls. A large portion of the URM building stock consists of terraced houses in which the presence of calcium silicate (CS) masonry is often used. The CS masonry is used to build the loadbearing walls, which are part of the cavity wall system. The cavity walls are generally composed of two leaves of masonry separated by an empty cavity, having a thickness of 8-6 mm, and connected with steel anchors. On the basis of the construction year, different masonry unit were adopted to build the inner loadbearing leave: in the period 1960-1980 small CS brick and general purpose mortar were used, while after 1980, the presence of large CS elements and thin mortal layers is predominant. Although these materials are often used in the northern part of Europe, little information is available on their material and structural performance. In this paper, a comparison between the behaviour of CS brick and element masonry is presented. The results of two experimental campaigns carried out at Delft University of Technology are reported. Both masonry types have been characterised at the material level by performing standardised destructive tests, such as compression, shear, and bending tests on wallets. The characterisation at the structural level is carried out by performing quasi-static cyclic tests on full-scale two-story high assembled structures.@en

Groningen, a province in the northern part of the Netherlands, suffers from earthquakes because of gas drilling. The residential building stock in Groningen was not designed for these loads. Over the years a lot of smaller and larger damage has developed, possibly - but not necessarily - caused by the effects of gas drilling. Delft University of Technology was asked by the Dutch government to come up with a method to reliably assess the cause of damage of masonry structures in Groningen. This paper discusses the developed approach for reliably assessing the causes of failure of masonry structures in earthquake-prone areas and the way innovative monitoring techniques were applied.@en

One of the geometrical restrictions associated with printed paste materials such as concrete, is that material must be self-supporting during printing. In this research paper a new methodology for 3D Printing Concrete onto a temporary freeform surface is presented. This is achieved by setting up a workflow for combining a Flexible Mould developed at TU Delft with a 4-degrees-of-freedom gantry printer (4 DOF) provided at TU Eindhoven. A number of hypothetical cases are studied, namely fully-printing geometries or combining 3D printing with casting concrete. The final outcome is a 5 m² partially-printed and partially-cast shell structure, combined with a CNC-milled mould simulating a Flexible Mould.

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