Large-scale additive manufacturing for architectural applications is a growing research field. In the recent years, several real-scale projects demonstrated a preliminary viability of this technology for practical applications in architecture. Concurrently, the use of recycled polymers in 3d printing has progressed as a more sustainable feed for small-scale applications. However, there are limited empirical examples on the use of additive manufacturing using recycled polymers in large-scale and real-life architectural applications. This project develops two design and fabrication approaches to large-scale manufacturing using recycled Polyethylene Terephthalate (PET) from single-use bottles into large design elements and tests them in a real-life project. The two designs are discussed in detail: a 4 m diameter dome-like chandelier printed with a robotic extruder using recycled PET pellets, and a 3.5 m diameter chandelier using a Fused Deposition Modeling (FDM) printing farm. The paper covers the state of the art of related printing technologies and their gaps, describes the printing process developed in this research, details the design of the domes, and discusses the empirical evidence on the benefits and drawbacks of large-scale additive manufacturing using recycled polymers. Overall, the research demonstrates the possibilities of large-scale additive manufacturing using recycled polymers, adding findings form a real-life project to the growing body of research on additive manufacturing in architecture.
As demographic growth and climate change effects increase, agriculture intensifies its pressure on the natural ecosystems from which life on Earth depends. In recent years, novel designs and resource-efficient manufacturing methods have been studied to alleviate the impact of food production, many of them incorporating farms into the urban context. However, farming in freshwater bodies remains largely unexplored and constitutes a great opportunity for innovation when land is scarce. Physical requirements for floating farming demand water barrier, solid, inert, and food-grade material with sufficient natural light transmittance, and lightweight, large-scale, complex-shaped components. Therefore, Polyethylene Terephthalate (PET) is presented in this paper as an ideal material for the fabrication of deployable floating farm modules, and Fused Deposition Modeling (FDM) is selected as the most appropriate manufacturing process for the required geometries. Today, recycled polymers in 3D Printing have progressed as a more sustainable feed for small-scale applications. However, there are limited built examples of Additive Manufacturing (AM) using recycled polymers in large-scale real-life applications. This project explores digital designs and fabrication approaches to large-scale manufacturing using PET obtained from single-use bottles to produce empirical prototypes tested in real-life conditions. The research prompted the digital design of a one-meter diameter translucent dome and a flotation platform, their fabrication using large-scale FDM, the assembly of the printed elements, and the monitoring of the farming module performance during operation. The paper covers the state of the art of related 3D printing technologies and their application in food production devices, details the design process of the floating module, explains the selected printing processes and interfacing strategies, and discusses the empirical evidence on the benefits and drawbacks of large-scale AM applied to the cultivation of food. Overall, the research demonstrates the possibilities of 3d Printing using recycled polymers, adding novel insights from a fully-functional project to the incipient body of research on digital manufacturing in food production.
The construction industry remains under immense pressure to reduce its material and climate related impacts. Increasing material demand and reduced building lifetimes have therefore motivated efforts for urban mining in buildings. Even though urban mining has been projected as a crucial measure for improving resource efficiency, its adoption as a practice in the construction industry remains at a very symbolic stage. Upscaling secondary resource recovery and reuse in the construction sector requires further efforts to understand urban mining feasibility from the perspective of project timelines, salvage time, skills and costs. Hence, this study develops an empirical research approach to measure urban mining feasibility and applies it to demolition-ready urban residential buildings stock in Singapore with semi-skilled construction workers. It develops indicators for urban mining feasibility based on planning stages, process change, behavioural practices and reuse-driven economic considerations. Based on urban mining of over 350 building components from 34 categories, results show an average of 1 to 12 min recovery time with an estimated urban mining cost from S$0.8 to S$9 per building component. Further, regulatory requirements for demolition permits can provide sufficient time for urban mining without affecting project timelines. Even though the mining skills of workers seem important, results highlights significant improvement in mining skills based on repeated salvage of specific building components. Results also provide robust evidence of reuse-driven urban mining feasibility in the case under study with significant prospects for embodied carbon savings. Overall, urban mining of buildings can contribute to net-zero targets and climate mitigation efforts with greater multi-stakeholder involvement and market push for reuse in the construction sector.
The research presented in this paper focusses on the concept of “Di-terial” which aims to merge digital design and fabrication technology with natural materials such as bamboo poles and raw timber. It proposes a digital workflow that uses sensing techniques to gain individual material information of natural, unprocessed construction resources and identify their individual strengths and characteristics and therefore its potential in load-carrying structures. This information is then used to develop bespoke designs and fabrication concepts, bridging the gap between unprocessed material and automated fabrication setups. Two case studies, developed to prove this concept, are described and compared. Both cases focused on the development of spatial structures using node-bar combinations of local resources.
AirMesh es la primera estructura arquitectónica del mundo hecha de componentes impresos en 3D en acero inoxidable, que demuestra las innovadoras tecnologías de diseño y fabricación digital desarrolladas por AirLab en la Universidad de Tecnología y Diseño de Singapur en Singapur. El pabellón ultraligero, situado en Gardens by the Bay, es a la vez un espacio de reunión y una escultura ligera.
The residential built environment plays a crucial role in supporting many human activities. In urban areas however, high-rise residential buildings require significant investment of material resources, which are stacked for a long time over the building's lifetime. Assessing the Material Stock (MS) of buildings has been the focus of several studies for insights into in-use materials and their potential availability as secondary resources. The study of material circularity, or the potential to reuse materials emerging from end-of-life buildings, has so far been mostly limited to metals. This study argues that material stock analysis at individual material or material categories e.g. mineral, or metals, need to be complemented with building component stock estimations to enhance the potential for secondary resource recovery. Based on a bottom-up stock analysis approach, we estimate both the material and component stock of public housing developments in the city-state of Singapore and associated annual in- and out-flows. Results show that public housing in this city, which accommodates over 80 percent of its residents, accounts for 125.7 million tons of non-metallic minerals, 6.52 million tons of steel, 6.45 million windows, 8.61 million doors, 1.97 million toilet accessories, 15.33 million lighting fixtures, 0.99 million kitchen accessories (such as cookstove, kitchen cabinets) and 52.54 million m2 of tiles. The average stock of materials for these residential buildings is estimated at 27.4 tons of non-metallic minerals per capita and 1.4 tons of steel per capita. The average annual inflow of materials has been estimated to be 1.94 million tons for concrete and 0.1 million tons of steel, with a considerably low outflow of 0.31 million tons concrete and 0.02 million tons of steel, implying growth in these material stocks. This study provides a methodological approach to quantify building material and component stock and flows, which can be used by policy makers, urban planners and designers to consider responsible resource consumption. In particular, material and component stock estimations like that reported in this study contribute towards component-level circularity in the built environment.
Automated fibre placement (AFP) is an advanced manufacturing process with a built-in heat and pressure system, an effective method for in situ consolidation of composite parts. In the present study, carbon fibre PA-6 prepregs were laminated by an IR-assisted AFP system, and the effect of process parameters on the resulting part quality was studied. Of the six fundamental process parameters, two parameters, i.e., laying speed and IR power were identified to be critical. Hence, the current study is focussed on the optimization of these two parameters while keeping the others constant. Three different combinations of IR power and laying speed were deduced to be optimised parameters for the material system used. In general, the laying speed should be increased along with the appropriate increase in IR power. Through visual and microstructural inspection, the laminate manufactured with these optimised parameters were found to have fewer defects and better consolidation when compared with samples manufactured with unoptimised combinations.
Velu, R., Vaheed, N., Krishnan, M., Raspall, F. (2020). Evaluation of engineering high performance thermoplastics for robot‐based 3D printing mould: a critical perspective to support Automated fibre placement process. Journal of Advanced Manufacturing Technology.