Shotcrete additive manufacturing

Shotcrete, also known as torcrete, is a construction technology invented in 1907 for placing cementitious materials onto a surface. The term is used to describe concrete that is transported at high pressure, using compressed air, through a hose line and placed at a specific location by spraying from a nozzle. The material, comprising aggregates, cement and water, is compacted by the impact energy of the air pressure. In contrast to the conventional concrete casting process, where conveying, depositing and compacting are independent sequential processes, in shotcreting all three processing phases can be completed in a single operation. There are two principal methods, the wet process and the dry process, and conventionally both require a nozzleman to control the application of material to the wall or required surface. To develop this technique to the next stage, the shotcrete process could be controlled by a robotic arm rather than a nozzleman, but to date there has been little progress on this in the construction industry.