Abstract
Concrete is commonly used as a construction material as it can be formed into almost any geometry by casting into a designated formwork. This property makes it a suitable candidate to manufacture geometrically complex modern building designs that have emerged from either pursuit of formalistic expression or performance optimization algorithms. However, these are not often realized because such concrete structures require custom-made formworks constructed out of extensive sacrificial materials. These are of one-time use and are discarded after the concrete has cured. In response, this thesis proposes ‘Smart Rapid Casting (SRC)’ – a prefabrication method that robotically extrudes clay to form a customized volumetric mold for concrete casting of complex building components in virtually any geometry. It takes advantage of clay as a phase-changing material and the layer-by-layer nature of additive manufacturing to incrementally build up a temporary mold in segments for concrete to be cast within simultaneously. After the concrete solidifies, the air-dried mold can be removed by high pressured water or air while the clay can be recycled for the next print job, which sufficiently reduces the mold material consumption. This research aimed to develop SRC to fabricate large-scale building components within a single print job. This was conducted in three stages: (1) The first stage developed the fabrication workcell with a focus on the end-effector and investigated different clay printing configurations to examine its printability, geometric accuracy, and mechanical performance to determine the ideal print configuration(s) for this method; (2) The second stage assessed the clay molds’ fabrication parameters in relation to the resultant casted concrete objects; (3) Lastly, the SRC method was implemented to investigate the feasibility of this strategy. These were demonstrated as various prototypes of varying scales to showcase the capabilities of the SRC method. The research presented in this thesis is built upon the development of this prototype robotic fabrication system that is seeking further commercialization