Effect of the Geometry of Representative Volumetric Masonry Elements (2024-09)¶

3D printing concrete (3DCP) uses mortar with aggregates with less than 4 mm diameters. The fact that it uses mortar makes the construction industry wary, as mortar is not usually a structural material. In Brazil, this technology is at an early stage, with many institutions and companies seeking to develop their own printing systems and cement mixtures. There are many questions about the resistant capacity of these printing mortars to withstand loads related to masonry construction. This work analyzes the compressive strength of representative masonry volume elements (printed blocks - PB) using three different geometries, considering the usual sizes of structural blocks commonly used as a fundamental element for the design of load-bearing walls. Therefore, tests were carried out in the fresh state to assess how the geometry affects the buildability and stability of the layers. In the hardened state, tests were carried out on small pieces, and compression tests were performed on PB with different geometries. Based on the experimental study, numerical simulations were carried out using the finite element method. The influence of geometry-related factors on the behavior of the elements analyzed was highlighted. The experimental results showed that the block geometry with S-type interlocks provided greater compressive strength due to its larger net area. In contrast, the PB with a perpendicular septum, similar to the MB geometry, presented lower strength. Numerical modeling was effective and correlated well with experimental results, proving an important procedure for 3DCP analyses.