Into the future of construction through 3D printing with shotcrete

In a factory near Hamburg, a start-up is using KUKA robots to build the digital future of urban and infrastructure construction. The team is not only revolutionizing the production of concrete components using 3D printing, but also the associated planning and execution processes.

New process for 3D concrete printing with robots

In the middle of a room, an L-shaped steel mesh basket is standing on a steel pallet. A thumbs-up sign is given to the operator who presses the start button on a touch panel. Seconds later, the hum and clatter of a concrete mixer fills the hall. Slowly, a machine raises itself in the workshop like a dinosaur come to life. But the scene is taking place in Hamburg and not in Jurassic Park. The bright white KUKA robot inside the installation is anything but frightening as it applies shotcrete to the steel mesh basket through a large nozzle in uniform movements. Layer by layer, a moist, shiny, blue-gray structure grows – at this point still with a wave-like structure and rough surface. This is soon smoothed into shape by a second robot with a large spatula-like tool.

During 3D printing with shotcrete, the material is applied directly onto the steel mesh.

Using shotcrete from a 3D printer to create an unlimited variety of shapes

“The robot with the shotcrete nozzle is the star of our system,” says Hendrik Lindemann. Right now, it is printing the prototype of an edge beam, as needed for a concrete bridge, for example. But the robot also has walls and other elements in its repertoire. Lindemann is a qualified architect and an expert in digital manufacturing. And, together with Roman Gerbers, Niklas Nolte and Alexander Türk, he is co-founder of Aeditive – a start-up company that is working on the digital future of concrete construction here in an old factory building near Hamburg.

In the construction industry, the first robot applies the shotcrete during 3D printing, and the second robot smooths it out.

The Concrete Aeditor can be used in both stationary and mobile applications

The heartbeat of the 3D concrete printing facility for use in both stationary and mobile manufacturing applications is determined by two six-axis KUKA robots from the KR QUANTEC ultra series. With a maximum payload of 300 kilograms and a reach of up to 3,900 millimeters, they are among the most powerful and compact industrial robots. As Foundry variants, they are particularly suited for operation in environments with a high degree of fouling, high humidity and high temperatures.

The key element for 3D printing with shotcrete: two KR QUANTEC ultra robots of the Foundry version.

Two robots, one goal: the perfect prefabricated concrete element through 3D printing with shotcrete

And this is exactly what the Norderstedt demonstration system with the 3D printer called ‘Concrete Aeditor’ is all about. The shotcrete nozzle developed in-house and guided by the first robot works hand in hand – or rather gripper in gripper – with a second robot, which handles the set-up of the structure in parallel. “Thanks to our new automated process, we are now able to produce even load-bearing concrete elements by means of 3D printing,” says Hendrik Lindemann. And all this from a single source. The Concrete Aeditor consists of production and material containers, the concrete mixing unit including a water and power supply, and its own software-based control system. “This allows our system to always be close to its construction jobs in precast plants or on building sites,” emphasizes Türk, the market strategist.

With comprehensive data integration for maximum process and cost transparency

With the aid of its own software, Aeditive enables its users to digitally generate the elements to be printed without the need for special prior knowledge. “The data generated during the production process help us to support users in quality assurance and to predict wear,” explains Lindemann. Türk rejects the idea that the Aeditive robots take away jobs: