University of Michigan’s DART Laboratory unveils Shell Wall—a concrete wall that’s lightweight and freeform 3D printed

The University of Michigan’s DART Laboratory has unveiled a new product called Shell Wall—which the organization describes as the first lightweight, freeform 3D printed and structurally reinforced concrete wall. The innovative product leverages DART Laboratory’s research and development on the use of 3D-printing technology to build structures that require less concrete. 

Ultra-lightweight, 3D printed concrete walls can facilitate the implementation of 3D concrete printing with thermal insulation while requiring less concrete and rebar. Compared to a conventional, solid concrete wall of equivalent size, Shell Wall delivers a 72% reduction in weight while offering the same structural strength. DART Laboratory’s technique allows for waste-free concrete construction and efficient use of material by placing it exactly where it’s needed for structural purposes.

Shell Wall’s 3D concrete printing method uses a computational model to optimize layout throughout robotic construction, reducing the use of concrete and creating greater design flexibility. Shell Wall supports its load case with material distributed in a grid of curved ribs. The concrete between the ribs is domed to increase stability and minimize the amount of material.

Shell Wall also can regenerate forms that closely match the initial optimization while accounting for fabrication and material constraints. For instance, during the design stage, it can automatically suggest alternative geometric features in areas where the deposited material might collapse due to a sharp angle or where the robot might collide with itself. 

By using commonly available concrete instead of highly specialized mixes, Shell Wall can mitigate challenges faced by the construction industry, including material and labor shortages, rising global greenhouse emissions, and new regulations. The product also can help meet rising demand for homes and infrastructure. Shell Wall’s use of commonly available materials can facilitate the practical implementation of 3D concrete printing for affordable and low-cost housing developments.