Lightweight Facade Research Articles

Thermal and manufacturing properties of hollow-core 3D-printed elements for lightweight facades

High-performance facades play an important role in achieving Net-Zero goals by 2050. As a facade manufacturing technology, 3D printing offers the opportunity to create site-specific and high-performance building envelopes. In this manuscript, the thermal performance of components fabricated with different Material Extrusion methods is studied experimentally, and the fabrication time is calculated, thereby examining both performance and fabrication viability. More specifically, this manuscript investigates the thermal performance of 3D-printed facades using Hollow-Core 3D printing (HC3DP) and explores the potential of this novel approach in creating thermally insulating, lightweight, and translucent building envelopes. The research compares the thermal resistance of HC3DP specimens to conventional material extrusion methods, such as desktop 3D printers, and granular-based, large-scale pellet extrusion. Different methods are used to determine the thermal resistance of specimens, including the dynamic thermal conductivity measurement for the desktop 3D-printed (3DP) specimens, and the steady-state hot box heat flux meter approach for HC3DP. The results demonstrate that HC3DP enables lower Thermal transmittance (U-value)s at lighter weight and faster printing speed, making it a promising avenue for further research. Additionally, the combination of HC3DP with aerogel is shown to create ultra-lightweight and thermally insulating 3D-printed facade elements. The potential of this new facade technology is also highlighted in comparison with established facade systems. All in all, the manuscript provides insights into the thermal performance of 3D-printed facades at different printing resolutions and emphasizes the importance of printing time and material consumption in determining the most promising 3D printing approach for lightweight and thermally insulating facades.

The best housing estate in Czechoslovakia

The Brno housing estate Lesna is undoubtedly an important achievement of Czechoslovak urbanism and architecture of the 1960s. It was built on the southern slopes north of Brno in 1962–1970 according to a project by a team of architects Frantisek Zounek, Viktor Rudis, Miroslav Dufek and Ladislav Volak. Although it was a standard housing construction made of prefabricated components, the architects did not want to hide its technical expression. They also fully copied it into the very urban arrangement of long blocks, which contributed to the fulfillment of the vision of the garden city. Close cooperation between the supplier, investor and designer was ensured already in the phase of elaboration of the project task. The architecture of residential buildings is based on the diligent efforts of the whole team to promote the use of a lightweight facade of a prefabricated house using parapet panels and strip glazing in the B 60 construction system. The unusually high-quality solution of the public space in the Lesna housing estate was mainly due to the time of its creation. Political liberalization in the 1960s allowed architects to come up with a generous plan for a free stop and thus perfectly fulfill the vision of a garden city. The population density of the Lesna housing estate, less than two hundred inhabitants per hectare, was multiplied by up to four hundred inhabitants per hectare in other housing estates of the "president Gustav Husak" era due to tightening economic indicators. Public greenery respecting the natural elements of the rugged relief required a different professional approach due to the extent of the exterior design. It was common practice that landscaping were carried out on residential complexes with a delay of several months and years after the first inhabitants moved in. The architects managed to reverse this common practice, so the first inhabitants moved to finished houses with access sidewalks, planted greenery and functioning residential amenities. This could not have been imagined by its inhabitants in the later realizations of housing estates. That is why the Brno housing estate Lesna is rightly called the best.

Experimental Measurement of the Accumulated Heat from the Operation System of the Heating in a Building with a Lightweight Envelope

Abstract The heating and cooling of buildings with large-scale ceiling systems nowadays is widely used in traditional as well as in new, low-energy buildings. This type of system is being employed in a building of the Civil Engineering Faculty (FCE), Slovak Technical University, in Bratislava. The building’s refurbishment in 2010 included the complete replacement of the building’s envelope. The replacement is a lightweight facade with a high percentage of transparent construction. Due to the differences between the type of envelope and the heating system, the operation of the heating system frequently causes thermal discomfort, especially during warm spring or autumn days. The aim of the measurements was to evaluate the control of the operation of the heating output, the appropriateness of the location of sensors measuring the outdoor temperature and possible improvement of the current control system to improve the heating system’s quality.

La rehabilitación como oportunidad de evolución de la fachada ligera . Caso de estudio: el Colegio de Arquitectos de Cataluña

La arquitectura moderna se caracteriza por su flexibilidad y fácil adaptación a las transformaciones. Las fachadas ligeras son muestra de ello, gracias a las mutaciones ventajosas que han aparecido en la envolvente en los últimos años. En este trabajo se intenta demostrar que a través de la rehabilitación de una fachada moderna es posible encontrar vías que señalen el camino de la evolución. En 2014, 12 propuestas de despachos españoles resultaron finalistas del concurso de la rehabilitación de la fachada del Colegio de Arquitectos de Cataluña (COAC), edificio que se encuentra dentro del Registro DOCOMOMO ibérico, el cual agrupa a los edificios del movimiento moderno más significativo de España y Portugal. Esta investigación confrontará las propuestas mediante el análisis de sus mejoras, agrupadas en cuatro aspectos arquitectónicos: tecnológicos, económicos, socio-ambientales y formales. Estas mejoras se abordan a través de estrategias que, por su recurrencia, finalmente señalarán los vectores de evolución para este caso.

Vertical safe separation distance between openings in multi-storey buildings having a fire resistant spandrel

A novel comprehensive methodology is presented for the determination of the vertical separation distance between floor glazing openings in buildings having a fire resistant non-flammable spandrel. The spandrel height is specified by requiring that the heat flux is less than a critical heat flux for glazing failure at the base of the opening of the floor above the floor of fire origin. For a specified room, opening geometries and fuel type, the heat flux at the base of this opening is calculated by using correlations for the flame height and heat flux distribution of the facade flames for under ventilated fire conditions in the compartment of fire origin. As the compartment opening increases a transition occurs from under ventilated to over ventilated conditions reducing the facade fire spread hazard. The methodology and results can also be applied for wooden and lightweight facade walls to predict fire spread behavior on the wall and towards the openings to floors above the floor of fire origin. © Owned by the authors, published by EDP Sciences, 2016 Language: en

Effect of Thermo-Mechanical Treatment on Mechanical Properties of AlCuMg Alloys

Technology development and new grades of alloys creation put before construction materials the number of requirements in range of durability and reliability of created constructions. Receivers expect materials with high strength properties, low production cost of the finished product, availability, corrosion resistance and low specific gravity. So the specific needs of customers mean that studies are constantly associated with the exploration of new materials and technologies that could meet made requirements [1,2,. In large scale this demand is met through the use of non-ferrous metals and their alloys. Selection of appropriate manufacturing techniques and the use of heat treatment procedures allow to obtain materials with better mechanical properties. Here the leading role has the aluminium and its alloys. Due to specific mechanical properties aluminium based materials are used in almost each field of industry. In aircraft industry they are used for the manufacture of fuselage elements in automobile industry the light alloys are used to make cylinder blocks, and other elements of internal combustion engines. In the construction industry they are used to manufacture windows and doors, as well as beautiful self-supporting lightweight facades. While the aluminium alloy products such as films or cans are also used in the food industry. The combination of physico-chemical and mechanical properties of aluminium alloys makes them the optimal solution for innovative design, thanks to them engineers can provide high strength associated with very low gravity. This allows to minimize the costs of subsequent use of the product, and while achieving good strength parameters. As part of this work the analysis of strain rate and temperature impact on mechanical properties of the tested alloy will be carried out. The experimental studies conducted in the temperature range of recrystallization (test temperature: 400°C, 450°C, 480°C, 500°C) using two strain rates 1 s-1and 0,1 s-1. This paper present the analysis of the application of high-temperature deformation changes in structure mainly caused by the dynamic recrystallization processes, which determine the optimal parameters of AlCuMg deformation process [. The proposed methodology of the research work made it possible to determine the effect of temperature-velocity parameters to changes in mechanical properties (inter alia: microhardness measurements) and changes in the structure of the material, which are closely related to the level achieved in mechanical properties.

Projeto de fachadas leves: especificações de desempenho

The proper design of lightweight facades implies, among other aspects, establishing performance requirements to minimize losses in building quality and cost, as well as maintenance. this article discusses and suggests performance, safety, and sustainability requirements and criteria that should be specified in a lightweight facades design for commercial multi-story buildings. The current article is part of a doctoral research project in progress. it is based on studies and comparative analyses of different building standards, as well as brazilian and international literature on the subject of performance. the results show that performance requirements and criteria should be discussed and defined early in the design phase, and performance issues should be dealt with at three levels: defining key facade requirements; identifying performance criteria for these requirements; and specifying the performance review of the facade and its components. only later should the technology to be employed and defined.