Physical modelling of unreinforced masonry walls using a sand-based 3D printer

Testing of small-scale physical models of masonry structures can be useful both to study Soil Structure Interaction problems and to provide large enough datasets to statistically validate the global level assumptions of masonry numerical models. This paper proposes the use of a sand-based Binder Jet 3D printer to manufacture 1:10 scaled physical models of masonry walls, that can be used within a centrifuge. As such printers can only print one material, mortar is emulated by controlling the micro-geometry of the printed material at the position of the joints (i.e., by printing joints). Walls were printed and tested in compression and cyclic shear under fixed-fixed conditions and constant compressive load. Different notch geometries were tried. The tested specimens were found to behave similarly in compression and shear to full scale masonry walls. A numerical model using a concrete damage plasticity model was built in Abaqus. It captured the cyclic response of the masonry walls with a reasonable accuracy. Therefore, such small-scale models can be used to expand centrifuge modeling in structural engineering.