Incorporating reinforcement in 3D-printing with concrete

Digital concrete construction has recently become the subject of very rapidly growing research activities all over the world. Various technologies involving 3D-printing with concrete have been developed, and the number of demonstration projects and practical applications has been increasing exponentially. Most of these approaches are focused on the placement of concrete, while the suggested solutions for incorporation of reinforcement are still rudimentary, and as such they limp behind the concepts for printing concrete. Since the use of (steel) reinforcement is mandatory in most structural applications, there is an urgent need to bring the technology of reinforcing 3D-printed structural elements forward. The article gives a critical overview of the current research and development with regard to reinforcement in the digital concrete construction and evaluates various approaches with respect to their compatibility with known concrete printing processes and existing guidelines and codes. When considering the steel reinforcement, the process for 3D-printing of steel elements by means of gas-metal arc welding as developed at the TU Dresden is also addressed. In addition, the possibilities and limits of reinforcement by means of fibre, yarn and textile are shown.