Effects of 3D-printing on the tensile splitting strength of concrete structures

Concrete and mortar are widely used construction materials that when processed with new 3D-printing techniques can be used to produce lighter structures with freeform shapes. Both conventional cast-moulded and 3D-printed concrete components can withstand high compressive though limited tensile stress, so reliable material data are required for correct dimensioning of those components. The indirect tensile test, or Brazilian test, as per EN 12390–6 A, is used to perform a tensile strength characterization of hardened concrete. In this study, Brazilian test results for both cast-moulded and 3D-printed specimens were examined, checking the inherent deviations produced during the printing process. The results reflected the tensile strength differences between cast and printed components, proposing a reduction coefficient applicable to cast specimen test results, to assist with the dimensioning of printed components at the design stage.