01_WEB The ILEK Tent by Frei Otto
02_WEB The ILEK Tent by Frei Otto
03_WEB The ILEK Tent interior
04_WEB The ILEK Tent interior
05_WEB The ILEK Tent interior
06_WEB The ILEK Tent interior
01_B&W_WEB The Graded Concrete Spraying Workshop@ ILEK
02_B&W_WEB The Concrete Spraying Hexapod Head
03_B&W_WEB The Concrete Spraying 3-Axis Nozzles
04_B&W_WEB The Concrete Spraying 3-Axis Nozzles

“In both its research and its teaching activities, the Institute for Lightweight Structures and Conceptual Design (ILEK) at the University of Stuttgart merges the architectural subject areas of design and form with the engineering fields of analysis, construction, and material science.

Following a highly interdisciplinary approach, the institute focuses on the conceptual and cross material development of all types of building technologies and structural systems and on the research and development of innovative building materials.

The scope of work spans from textile and glass construction, to new possibilities in steel and prestressed concrete design, to ultra-lightweight structures using adaptive systems. From the individual details to the overall system, the aim is to optimize form and structure with respect to energy and resource consumption, durability and reliability, recycling potential and environmental sustainability.

Vital to the success of this approach is the integration of the institute in an active international network with other leading research and teaching institutions, as well as the collaboration with numerous industry partners.

Part of the ILEK is housed in the famous tent structure, originally erected as a prototype to test the construction and assembly procedure of the German Pavilion for the World Exhibition 1967 in Montreal. Today, the building in Pfaffenwaldring 14 is widely regarded as an icon of modern architecture.”

ILEK, Tent Structure by Frei Otto Photos


Over the course of the Visiting School we will have access to the Institute’s workshop facilities and the concrete spraying robot for graded concrete manufacturing. The concrete spraying technology has been developed by Winkel (a linear technology specialist) in collaboration with the University of Stuttgart’s Institute of System Dynamics (ISYS) and is being used for fabricating building components that consist of customised material properties that correspond to applied structural loads over their volume.

In terms of the technical specifications of the concrete spraying, the nozzle is “managed through a SLE (Steel-Linear-Unit) heavy-duty multi-axis portal” and can move three-dimensionally: “3,000 millimetres on the X-axis, 2,200 millimetres on the Y-axis, and 800 millimetres on the Z-axis.” A mounted hexapod on the Z-axis, also means that the nozzle can move independently from the portal. Effectively, “two different concrete mixes (one solid, the other one porous) are mixed in the mixing nozzle and then sprayed into the required shape. The material properties change with the mixing ratio. This can be used to produce more solid and durable concrete or lighter, more porous concrete depending on what is required.”

The technology promises to have radical impacts on environmental and resource savings, by reducing the amount of overall cement and concrete material per component. At present and in conventional concrete manufacturing, the cement industry alone “still accounts for around 6 per cent of worldwide CO2 emissions… Should the grading process be used in the industry, it has the potential to revolutionize the manufacturing of concrete building components: It will allow savings of up to 60% of the mass relative to the previous mass and 35% in terms of CO2 emissions.”

The objective during the course of the Visiting School will be to utilize this technology in order to generate novel graded concrete configurations, as well as pushing the limits of what forms can be designed with graded concrete.

Further information on the concrete spraying technology

Video of the concrete spraying robot