Designing with recovered precast concrete elements

In The Netherlands, two shortcomings of the country’s building stock have become increasingly prevalent in recent years: high vacancy rates of office buildings (8.2% as of 2022 and a high demand for residential buildings (shortage of up to 315,000 dwellings as of 2022). This paper investigates how the reuse of whole precast concrete elements from office buildings can lead to more sustainable residential building designs. As a case study, suitable ‘donor’ office buildings and an apartment building design are identified. First, the apartment building design is modified to employ as many suitable recovered elements as possible (while maintaining the original building geometry). This leads to a 69% reduction of new concrete used and a 46% reduction of CO2 output. Second, the design is adjusted to an optimal grid layout for maximal component reuse. This further improves the outcome to 90% and 60% respectively.</p

Smart &amp; Adaptive: Why? How? What?

Intreerede Delft University of Technology, 25 november 2009IntreeredeArchitectural Engineerin

Adaptive structures and design concept of transformable joints

This article describes the research framework for adaptive structures and the design concept of transformable joints. The research of adaptive structures can be splitted into different scales: deformation mechanisms (whole structure), cooperation mechanisms (inter-component) and actuation mechanisms (intra-component). This research will focus on transformable joints, which are based on special material properties (actuation) to accomplish the change of joint stiffness between locked and released states (transformation). Thereby, the control of DOF can be achieved, in order to finally realise the whole structure’s form change (deformation). Alternatively under shock loads, the joints release and the structure occur certain deformation to dissipate energy and adjust to external loads. Afterwards, the structure recovers its original shape and removes residual strain through special/smart materials. Then the released joints relock again. By comparison of natural role models and adaptive structures, there are many similarities between them that we can learn from nature. In future research, e.g. adaptive stiffness, the experimental tests of potential materials and prototypes will be the main research methods. While for adaptive geometry, the knowledge of robotics, especially the part of geometric representations and transformations, will help to express this problem in mathematical way. This part will be mostly in conceptual level, so computer simulation will be used. The final goal of this research is to develop energy dissipation and shape-morphing strategies using transformable joints under varying loads as well as shock impact. These kinds of joints can not only be applied to tessellated shell structures, but also introduced to active facade systems

Towards smart building structures : adaptive structures in earthquake and wind loading control response – a review

This article is a review about applications for non-passive control response of buildings (namely active, hybrid and semi-active systems), wherein the degree of integration between control devices and structural system is explored. The purpose is to establish the current state-of-the-art in the development of ‘smart building structures’. A proper framework is proposed, therefore, for concepts such as ‘intelligent’, ‘smart’ and ‘adaptive’ while they make reference to a building which possesses an actively controlled response. Geometrical integration between control device and structural system is addressed as the key to allow further improvements in the achievement of truly ‘smart’ structures. Conclusions point out the fact that despite the advances done – especially in the field of structural control technology – there is no integration of devices within the host structures, and the reasons why further research must be developed in this directio

Mechanical characterization of a shape morphing smart composite with embedded shape memory alloys in a shape memory polymer matrix

This article presents a smart composite that shows a reversible bending deformation from an initial flat configuration into a 90° angle controlled by local thermal activation. The novelty lies within the structural fixation of the deformation at room temperature without continuous energy input. The new structural architecture of antagonistic performing shape memory alloy actuators embedded in a shape memory polymer matrix is presented. The shape memory polymer is locally heated from the rigid glassy state to the easily deformable rubbery state by integrated heating wires. By subsequent activation of the different shape memory alloy actuators by resistive heating, the reversible performance can be realized. By deactivation of the heating wires in the shape memory polymer, the shape memory polymer fixates the deformation in its rigid condition. The actuation characteristics of the smart composite are investigated by thermo-mechanical experiments. The performance of the smart composite was investigated by thermo-mechanical experimentation of the individual components. The results show that a 90° bending deformation is feasible with the current material dimensions, but repeated deformation is restricted due to fatigue of the alloy. By superposition of the bending forces of the individual components, it is possible to estimate the bending angle of the composite material

Deployable structures using non-singular rigid foldable patterns

The opportunities of fully foldable structures are well utilized in some industries, but are only rarely applied in the built environment. In the first part of this study, a number of folding typologies are investigated and their (un)favourable properties are related to the built environment. In the second part, the results of the first part are exploited in order to design an adaptable pavilion. The conclusion of the first part of the study is that there are multiple folding typologies which can generate a wide variety of forms. However, there is especially one typology with a high potential to translate the folding patterns into real structures. This folding typology is called non-singular, rigid foldable. The advantage of this typology is that the individual surfaces do not bend during the folding motion, while the degrees of freedom (DOF) are only dependent on geometric characteristics of the folding patterns. The second part of the study uses the results from the first part in order to design an adaptable pavilion. To design this pavilion a variant study is performed with folding patterns which belong to the stable adaptive typology. The variants are compared to each other with respect to their: structural performance, innovative appearance, effective floor space range and ease of transportation as well as deployability. From this study the final variant is studied in more detail and a structural analysis is performed based on the Eurocode for temporary structures. In this non-linear structural analysis, the structure is modelled in various configurations. The resulting design leads to an innovative pavilion which is able to transform in multiple configurations by only moving the support points, while it is stable for every possible state

Deployable structures using non-singular rigid foldable patterns

The opportunities of fully foldable structures are well utilized in some industries, but are only rarely applied in the built environment. In the first part of this study, a number of folding typologies are investigated and their (un)favourable properties are related to the built environment. In the second part, the results of the first part are exploited in order to design an adaptable pavilion. The conclusion of the first part of the study is that there are multiple folding typologies which can generate a wide variety of forms. However, there is especially one typology with a high potential to translate the folding patterns into real structures. This folding typology is called non-singular, rigid foldable. The advantage of this typology is that the individual surfaces do not bend during the folding motion, while the degrees of freedom (DOF) are only dependent on geometric characteristics of the folding patterns. The second part of the study uses the results from the first part in order to design an adaptable pavilion. To design this pavilion a variant study is performed with folding patterns which belong to the stable adaptive typology. The variants are compared to each other with respect to their: structural performance, innovative appearance, effective floor space range and ease of transportation as well as deployability. From this study the final variant is studied in more detail and a structural analysis is performed based on the Eurocode for temporary structures. In this non-linear structural analysis, the structure is modelled in various configurations. The resulting design leads to an innovative pavilion which is able to transform in multiple configurations by only moving the support points, while it is stable for every possible state

Adaptive arch : active stress minimization in a thin arch structure

The concept of adaptive structures is based on the approach that the structural behaviour of a design is not established only once during the initial design phase, but rather that the structural response is controlled continuously during its lifespan via the integration of active components. The adaptive control of structures focuses on the manipulation of the internal stresses, the displacements as well as the control of vibrations. This can optimise the structural behaviour in varying extreme loading situations resulting in substantial material savings in comparison with passive structures. The subject of this paper is the active manipulation of the load-carrying behaviour of a flexible arch structure. The goal of this manipulation is the homogenization of the stress fields and the minimization of the maximum stresses governing the design. Within the context of this work, the active rotation of the supports is investigated as control mechanism. The optimal activation processes are determined using numerical optimization procedures. Due to large displacements of the structure, geometrically nonlinear effects are included during the determination of the optimal support rotations. An experimental lab-structure is built and the practical application of the control system is realized. Several software programs and hardware are coupled to form the control loop. The practical control system is able to actively control the structure for (quasi) static loads. Also a basis for a dynamic control system is formed

A vibration control strategy using variable stiffness joints

Adaptive joints are structural joints made of materials with enhanced transduction properties that can vary their stiffness via solid-state actuation (e.g. thermal, mechanical). In this work, stiffness tuning is used to switch the joint between a ‘locked’ (e.g. a moment connection) and a ‘released’ (e.g. pin) state. Previous work has looked into the feasibility of using variable stiffness joints during shape and force control in order to reduce actuation work. This paper focuses on control of the structure dynamic response to loading. The natural frequency of the structure is tuned to escape dangerous resonance conditions in two ways: 1) a geometric reconfiguration via large shape changes or 2) via the change of stiffness of the joints. Two case studies are considered: 1) an active frame integrated with four actuators fitted on tubular elements which are connected by a shape memory polymer joint 2) a planar truss structure. Experimental tests on the active frame have shown that by varying the length of the linear actuators, large shape changes can be employed to effectively change the natural frequency of the structure. During shape change, the joint stiffness is lowered to ease geometric reconfiguration. For the planar truss case study, simulations have shown that the ‘release’ or ‘locking’ of multiple joints can be employed to change the eigenfrequencies, the more so the higher the eigenmode

Resource-efficient structural design

The building and construction industry is by far the most resource intensive sector in the European Union [1] and the numbers worldwide are comparable. This sector, which is based on a very strong responsibility of architects as well structural engineers takes approximately 50% of all primary raw materials and therefor exhausting natural resources substantially. In the past decades the focus in the construction industry was mainly on the reduction of energy consumption of buildings as well as use of renewable energy, but the impact of material use will be in the spotlight in the future as well