Impact of Robotic 3D Printing Process Parameters on Inter-Layer Bond Strength (2022-07)¶

One of the target areas of concern with large-scale 3D printing (Additive Manufacturing (AM)) processes is the need to enhance the bond strength between adjacent printed layers. In this paper, the impact of three process parameters on interlayer bond strength in paste was investigated. Utilizing an alternative clay-based material in large-scale AM was considered in this research due to concerns about global carbon emissions associated with the concrete industry. This paper proposes an approach by manipulating process parameters that alter the geometry of the layers on the meso-scale to emulate densification and to enhance friction between consecutive layers by either periodically increasing print area or enhancing compaction during the print process. The standard flexural test was performed to obtain the flexural strength of 95 printed specimens. Results showed that periodically manipulating the standoff distance of the nozzle appears to function akin to compaction in conventional concrete casting methods and improves the interlayer bond strength under shear by 41% on average.