New Shell Wall technology claims to decrease weight of concrete walls by more than 70%

While 3D concrete printing (3DCP) technology is known for its efficiency in building construction, a new variation of the technology called Shell Wall is said to be even more effective. According to claims, the Shell Wall technology reduces the weight of concrete walls by 72% compared to traditional walls.

On typical building sites that use 3DCP, an extruder nozzle operated by a robot moves along parallel straight lines to the ground. It builds molds for walls one layer at a time horizontally. When the hollow centers of the molds are filled with rebar and more concrete, the walls are finished.

Dr. Mania Aghaei Meibodi and her team at the University of Michigan’s DART Laboratory (Digital Architecture Research Technologies) have pointed out that the current 3DCP building process uses excess concrete and restricts building design to basic shapes. The university’s Shell Wall technology aims to address these issues.

The process starts with developing a computerized model of the structure that identifies the most efficient distribution of material required to provide the necessary strength in each building component. This implies that no materials are added where they are not needed.

Following the computer model, the 3DCP print nozzle constructs wall elements layer by layer. The walls comprise curved vertical structural ribs and thinner curved membranes bridging the spaces between them. The concrete layers are placed in a non-planar manner, departing from the conventional parallel approach to the ground. While building each element, vertical sections of rebar are added within the hollow ribs, and thermal insulation is placed inside the hollow membranes.

The Shell Wall technology has undergone small-scale tests which show that the weight of Shell Wall elements is 72% less than that of solid concrete walls of the same size, while offering equivalent structural strength. Full-scale tests of the technology at real construction sites are currently being planned.

Source: University of Michigan