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In recent years, 3D printing has been more and more used in the development of buildings and building elements. Mostly-printed structures are subjected to compression that is oriented perpendicular to the layer laying direction. When applying load in this way, the printed structure exhibits characteristics similar to masonry structures. However, as the technology and application of 3D printing develop, the structures also become more complicated and subjected not only to direct compression but other stresses as well. In this paper, long-term properties together with compressive strength were determined for 3D-printed specimens with load applied in the same direction as the layers are laid. The long-term and mechanical properties were compared with cast same-composition specimens. Results show that for the printed specimens, the compressive strength was more than two times lower than cast specimens, while the creep properties were slightly lower for the printed specimens. [ABSTRACT FROM AUTHOR]

Foamed concrete has been used as a building material since the early 1920s. In the beginning, it was used as an insulation material with very low density. Since then there have been attempts to improve the structural properties in order to increase materials load-bearing capacity. In the present-day foamed concrete is being used in soil reinforcement, manufacturing of building blocks and other sorts of construction materials (Mugahed Amran, Farzadnia, & Abang Ali, 2015). The aim of this article is to determine the behaviour and long-term properties of foamed concrete. Cylindrical specimens (Ø46×190 mm) were used for creep and shrinkage testing. The creep properties of the specimens were determined by loading them with 20% and 60% of the ultimate compressive stress value (Sprince, 2015). The compressive strength, creep, shrinkage and specific creep of the material were examined. It was determined that during 90 days of creep testing the non-linear creep deformations (specimens loaded with 60% of the ultimate stress) are 4 times larger than linear creep deformations (specimens loaded with 20% of the ultimate stress). Also, changes in the modulus of elasticity of foamed concrete were researched over time. Foamed concrete modulus of elasticity reached 12.21 GPa on the 28th day, 12.49 GPa on the 62nd and 14.23 GPa on the 144th day since the specimens were made. [ABSTRACT FROM AUTHOR]