Concrete, the Predestined Building Material for Additive Manufacturing (2018-09)¶

With a total German construction volume of around € 370 billion in 2017, the construction industry is one of the key industries in Germany. This enormous added value is largely created using technologies that have been established for decades. As a result of conventional and standardized construction methods and simple construction systems, technological progress in the construction industry has been slow for years. Particularly in the area of materials, innovative developments such as ultra-high performance concrete (UHPC) or textile concretes have only been used sparingly in construction practice. Digitalization, which represents a significant incentive for further growth in other industrial sectors, is currently still limited to the area of planning in the construction industry. In order to take advantage of the opportunities that digitalization offers the construction industry, it is important to set the course today and close the digital chain from planning to production. Robot-supported additive manufacturing (3D printing) can be a core element of this. Additive manufacturing allows the application of new design principles that go hand in hand with a more intelligent and efficient use of materials and resources as well as a completely new freedom of design. Due to its free formability, concrete in particular seems predestined for additive manufacturing. Numerous technologies are currently being researched worldwide that demonstrate the potential for innovation and fundamental applicability in concrete construction. Examples include shotcrete 3D printing (TU Braunschweig), extrusion-based processes such as contour crafting (University of Southern California), 3D concrete printing (Loughborough University, TU Eindhoven, Sika and others) or ConPrint3D® (TU Dresden) and particle bed 3D printing processes such as selective cement activation and selective glue extrusion (TU Munich, TU Braunschweig, D-Shape). The commitment of well-known building material manufacturers, formwork manufacturers and construction companies also demonstrates the economic potential of these technologies. Additive manufacturing will permanently change construction processes. However, there are still numerous challenges to overcome on the way to practical application. For example, the significant interactions between material and process in additive manufacturing give rise to new issues for both the material and the process technology. In addition, the greatest challenges lie in the integration of the reinforcement and the large scale of the elements to be produced. It goes without saying that further interdisciplinary basic research will therefore be necessary in the coming years. In order to further develop this technology, a fundamental understanding of the mechanisms is essential. At the same time, however, the first steps towards real applications must be taken now. This requires the courage of the construction industry to integrate new digital production technologies into their work processes together with research partners. The future of construction is being designed today. Help shape the future. The time is ripe to take the step towards additive manufacturing on a large scale.