Failure behavior of RC beams by means of 3D concrete printing

Flexural tests were conducted on RC beams by using material extrusion 3D printing technology.The used mortar does not include any fibers, and the beams have horizontal and vertical interlayers.It was clarified that the compensation plane was maintained within the cross section, the neutral axis rose with the propagation of flexural cracks.The strain of the mortar at the extreme fiber in compression was about 3000 micron, and flexural failure with interlayer delamination in compression zone was observed finally.In addition, delamination of multiple filament interlayer was observed at the rebar position.The interlayer bond strength was measured and found to be about 30% of the splitting tensile strength of mortar itself.