Abstract
The life cycle of buildings and infrastructure is a complex journey. It starts with raw material extraction and manufacturing, followed by construction and assembly of the building before reaching operation and maintenance. The cycle includes demolition, disposal, reuse, or recycling. The relevance of the ecological footprint of these phases is dynamically changing. Modern buildings operate with renewable energy and other technologies to ensure comfort while minimizing the emission of carbon dioxide. Considering these significant reductions in operational energy, the focus is increasingly turning to embodied energy in the total sustainability assessment.
In this context, additive construction offers tremendous potential, as it promises efficient material use. Now, important research is required to address key challenges related to the life cycle: What materials should we 3D print with, and where should they come from? How can we construct large-scale structures? How can additive manufacturing help to reduce operational energy? What happens with 3D-printed building elements after the demolition of the building?
In answering these questions, it is important to avoid naive, biased shortcuts, and conduct careful assessments instead. The solutions will not be a single fabrication approach but a plethora of methods that respond to the various construction tasks and the individual local context. Additive construction should, therefore, address not only new buildings but also renovation strategies and the fabrication of other infrastructures. Researchers need to work application-oriented, trying to maximize an immediate impact. But in parallel, fundamental research should not be ignored–essential to find answers to tomorrow's questions.
The first of our special issues on additive construction concentrated on 3D concrete printing, whereas the second dealt with additive manufacturing of concrete formwork.
In the last issue of our miniseries, we collected studies in the field of additive manufacturing that expand boundaries and explore unknown territories. The presented research broadens the scope for the mentioned reasons: working with new materials, new additive processes, and new fields of applications. The selection reflects well the interdisciplinary character of this research area: expertise from robotics, computer graphics, material science, architecture, and engineering need to be bundled together. Remarkably, most of the studies in this issue go beyond layer-based manufacturing and use custom robotic fabrication setups.
The first article discusses a core-free robotic filament winding process that can create large ultra-lightweight composite building elements. The second submission introduces wood-based filaments as a novel material system for robotic additive manufacturing. With robotic plaster spraying, the third article contributes to the field with new control and automation strategies. Nonplanar printing strategies of the subsequent study allow support-free printing of complex geometries.
The article on impact printing based on clay further expands the definition of additive manufacturing. The fifth article highlights another novel field of application of additive manufacturing with 3D-printed aggregates in asphalt concrete. Finally, the authors of the last article take us on a journey to Mars, presenting laser melting by a mobile manipulator for extraterrestrial applications of additive manufacturing.
Thank you to all authors and reviewers for their essential contributions to all three issues. The focus on additive manufacturing would not have been possible without the editorial team around Skylar Tibbits and especially Anastasia Hiller.
We wish to encourage critical discourse and stimulate further research about these relevant topics with this series. Therefore comments, feedback, and direct contributions to the journal are very welcome, please contact us at (3dp_eo@liebertpub.com).
We are witnessing another turning point of construction, and it is our chance to determine its new direction. We need to learn to harness the full potential of additive manufacturing—toward a digital building culture and a more diverse and sustainable built environment.