Architecture, Structures and Construction最新文献

Under urgent sustainability targets, the building industry craves for renewable and recyclable biomaterials as cellulose is a fiber; Lignin is a plant-derived low-cost polymer with remarkable properties, yet its valorization is in its infancy. Recent studies have shown potentials to combine cellulose and lignin into a renewable bio-based material for the built environment, with the use of additive manufacturing to allow geometric customization and local control of material. However, previous studies also highlighted crucial issues to be solved. One main challenge is the lack of knowledge on combinations of lignin and cellulose with different binders to achieve a paste suitable for 3D printing, leading to a material applicable in the built environment. To contribute overcoming the challenge, this research aimed to explore various combinations of cellulose, lignin, and binders and to study the extrudability of the resulting paste using a clay extruder installed on a robotic arm. Several combinations were explored, evaluated, and compared. The four recipes with the highest scores were used to produce samples for tensile and three-point bending tests, water absorption and retention tests, and microscope analysis. The overall outcome has shown similarities between the mechanical properties of the mixture developed using methylcellulose as the binding agent and rigid polymer foams, such as the ones commonly used as insulation panels. Moreover, the material mix with the highest score in the preliminary assessment was further applied to fabricate samples with varied geometries to assess its potential and limitations combined with the fabrication process. Finally, two demonstrators were produced to explore the printing process for different geometric configurations: conceptual window frame and structural node were designed, and 3D printed as proof of concept.

Growing global demand for sustainable development places immense pressure on the construction industry to select and promote sustainable construction practices. The selection of sustainable construction practices is a challenging task, as there are numerous variables and uncertainties involved in the concept of sustainability and a consistent and widely accepted framework for assessment and evaluation seems to be lacking. Based on an extensive literature review on sustainability, sustainable construction was redefined and evaluation frameworks were identified for comparison. Furthermore, a conceptual framework is proposed by identifying specific indicators and criteria relating to the objectives of sustainable construction (sociocultural, economic, technical and environmental) to evaluate the sustainability of construction practices. Recommendations for the application of the proposed framework is also presented.

This paper discusses a novel, compact sound absorption solution with high performance at various frequencies, including low frequencies, achieved through the effective use of Computational Design and Additive Manufacturing (AM). Sound absorption is widely applied for reducing noise and improving room acoustics; however, it is often constrained by conventional design, material properties and production techniques, which offer limited options for customising performance. This research highlights that AM, in combination with computational design tools, can support the development of novel sound-absorbing products with high performance based on the principle of viscothermal wave propagation in prismatic tubes. The potential of these designs was explored via two studies of customised sound-absorbing panels whose performance was measured in a reverberation room. A custom measurement technique was used based on logarithmic sweeps with high-resolution FFT analysis. A comparison of the measurement results with the theory of viscothermal wave propagation indicated good agreement; thus, this study demonstrates the possibility of developing new concepts and design methods for novel room acoustic devices.

Optimizing the shape of concrete construction elements is significant in reducing their material consumption and total weight while improving their functional performance. However, the resulting non-standard geometries are difficult and wasteful to fabricate with conventional formwork strategies. This paper presents the novel fabrication method of mineral foam 3D printing (F3DP) of bespoke lost formwork for non-standard, material-efficient, lightweight concrete elements. Many innovative formwork studies have shown that stay-in-place formwork can help to reduce waste and material consumption while adding functionality to building components. Foams are particularly suitable for this application because of their high strength-to-weight ratio, thermal resistance, and good machinability. F3DP allows the waste-free production of geometrically complex formwork elements without long lead times and production-specific tooling. This paper presents the material system and robotic F3DP setup with two experimental case studies: a perforated facade panel and an arched beam slab. Both cases use concrete as structural material and strategically placed custom-printed foam elements. In this first preliminary study, concrete savings of up to 50% and weight reduction of more than 60% could be achieved. This is competitive with standardized solutions such as hollow-core slabs but, in contrast, allows also for non-standard element geometries. Additional functionality, such as programmed perforation, acoustic absorption, and thermal insulation, could be added through the stay-in-place formwork. Moreover, the challenges and future developments of F3DP for sustainable building processes are discussed. Further studies are required to verify the findings. However, considering the urgent need for resource-efficient, low embodied-carbon solutions in the construction industry, this work is an important contribution to the next generation of high-performance building components.

Flat panel photobioreactors consisting of different layers of glass panes, designed to allow heat and microalgae biomass production in a water layer by solar radiation at the facade of buildings (i.e. bioenergy facade), were acoustically examined and further developed for increased sound insulation against external noise exposure. The sound insulation was first examined by simulations on double-, triple- and four-skin bioreactor variants. Parameters such as the distance between panes, the number and types of layers, as well as the material and thickness of the glass panes, were varied. Especially the influence of decoupling layers and an airlift on the sound reduction index was evaluated. Based on the simulation results, a modular prototype was developed which could be converted into a double-, triple- or four-skin structure as required. The sound reduction of these was studied in an acoustic window laboratory experimentally. The highest measured weighted sound reduction index of 51 dB was obtained with a four-skin photobioreactor variant with four glass pane layers and a water layer. The weighted sound reduction indexes for alternative four-skin opaque prototype variants with a plasterboard layer were 2—3 dB lower. The double- and triple-skin variants achieved 43—47 dB. The use of XPS as insulation material in the outer air layers of the triple- and four-skin variants reduced the weighted sound reduction index by 2 dB. The airlift needed for turbulent mixing of the microalgae had no effect on the sound insulation but increased the average ambient noise level by up to 10 dB. With 51 dB, the four-shell photobioreactor prototype achieves sound insulation class 5 according to the german regulation VDI 2719 for windows and thus fulfills the function of a sound insulation element in the facade of buildings or in a soundproof wall.

Consideration of architectural beauty in the built environment is growing as the broader concept of sustainable design replaces the more narrowly defined concepts of high performance or green building. This work is a part of Beauty in Building (BiB) research conducted by a team of architects and engineers working to understand links between architectural beauty and building performance. This work presents the exploration findings on what impact architectural beauty may have on building energy performance. A sample of 35 case studies contrasting high performing buildings with architecturally beautiful and high performing buildings was evaluated using the developed BiB matrix. Features that distinguished the best performing buildings from the rest of the sample population were identified based on the results of the case study evaluation. Building energy models representing these building features were then developed for quantitative evaluation of energy performance through energy simulation. Relative importance to beauty and energy performance of each of the features was determined and presented as weighting factors. The results illustrate those features that exhibited density, a combination of multiple systems, in the designs offered better performance relative to both beauty and energy.

Strategies based on an optimal balance between standardization and individualization must be implemented to successfully overcome the current low level of automation in building construction. Project-specific adaptability can be ensured by a combination of automated machine technology and digital planning tools available today. In addition to achieving economic advantages, the focus is on improving sustainability factors, which concern both material consumption and functionality and improved use of resources and energy for building production and operation. The results of research into “lightweight aerogel concrete technology” has shown that an innovative liquid material mixture with insulating properties can be successfully implemented in an automated production process. An adaptive system for standardized wall, ceiling, and floor panels was developed, which can adapt to specific functionality needs and thus address the requirements of individual building tasks while keeping economic as well as architectural factors in mind. The advanced mono-material complies with current European regulations for insulated wall structures, considering the requirements for load-bearing capacity. Due to its homogeneous insulation effect across the entire element section, the aero lightweight concrete allows for intelligent detailing and connection principles and prevents the formation of thermal bridges. The relationship between material composition, material production, construction method, and building operation is essential for a circular planning process. Robotization as a multiple fabrication technology may facilitate these parameters in one cycle. The new technology allows for the crucial transition from research to an end-to-end construction workflow that maps the entire process chain, from concept planning to design and joining principles up to fabrication and assembly.

Polyhedral structures are a fascinating and efficient case of structural virtuosity. However, their adoption to date has been limited because of geometrical, structural and fabrication complexities. This paper introduces a modelling pipeline to provide a rigorous -yet practical- approach to the challenges linked to the realisation of 3D polyhedral structures, from early-stage design to fabrication. A custom-developed modelling add-on is utilised for reconstructing the underlying topology of 3D polyhedral structures and implementing a component-based approach for the design development. Concurrently, an innovative digital fabrication strategy based on Additive Formwork Manufacturing is presented, with a detailed description of the process and illustration of a fully-functional physical prototype. Methodological and software developments are applied to the fabrication experiments where the approach is tested with in-depth design and construction insights. The approach is ultimately discussed for the development of real-world structures and in light of the potential adoption by non-expert computational designers.

Abstract

Traditional fabrication methods of architectural ceramics seek to minimize plastic deformation during wet-processing by prioritizing sectional consistency. Adapting sectional thickness is critical for improving material performance to address localized functional requirements. Functionally Graded Additive Manufacturing (FGAM) enables a design-to-production process where sectional profiles can be designed to achieve targeted performance characteristics. This research utilizes FGAM with Liquid Deposition Modelling (LDM) to prioritize sectional performance over form generation. Functionally graded 3D printed ceramic screens are produced for decorative lighting applications. Custom tool path generation is implemented to create modelling techniques that capitalize on the viscoelastic properties of clay. The prototypes obstruct, reflect, and transmit light across their component sections to grade brightness and illumination. This paper outlines the methods involved in altering plastic deformation during the wet-processing of porous clay structures and the corresponding light-scattering behaviour of their ceramic counterparts. The light screens are organized by the resolution of porosity within each series of prototypes. In the 'Small' typology, deformation is utilized at the scale of a single print layer to form a dense multi-layered sectional condition that disperses light evenly. In the 'Medium' typology, deformation is compounded over multiple layers to form directional light apertures. In the 'Large' typology, extrusion variation is introduced to exaggerate deformation and generate multi-directional light scattering.