70NANB24H306

The construction industry is poised for a major transformation through the additive manufacturing approach of field-based concrete printing, an emerging technology using large-scale 3D printers to construct physical infrastructure. Most 3D printing is performed in a controlled environment. In field-based construction, many factors, especially environmental ones, affecting printed concrete product quality are difficult to control. These factors drive the need for field-based quality control methods. A significant hurdle to the anticipated growth of field-based concrete printing is consistency of strength in the bond between successive layers of the printed cementitious materials. The end goal of this work is to develop a commercial system for measuring and controlling the quality of this interlayer bond strength under multiple environmental conditions likely to be encountered in the construction industry, including temperature, humidity, wind, dust, and printing delays. Phase II research focuses on measurement of interlayer bond strength of laboratory printed specimens with deliberately varied environmental conditions and print intervals resulting in predictive algorithms based on machine vision data. These algorithms will be used to build a commercial system that monitors the mortar continuously during placement and adjusts the output of the printer in real-time to obtain optimal interlayer bond strength.