On the Issue of Measuring the Strength of Additively Manufactured Concrete

One of the most actual issues in the development of construction printing is the development of sound methods for determining the main properties of additively obtained composites. And this applies not only to special properties, such as printability or shape stability, but also, it would seem, well-studied strength indicators. Most researchers in their works pay attention to the fact that the strength of samples obtained using molds does not correspond to the same indicator in printed structures. In this regard, this paper proposes a method for determining the strength of samples of standard sizes obtained by cutting out of a printed array. The array printing scheme assumes that each sample contains a large number of contact zones of layers, which are a weak point in the system under consideration. This approach allows considering the additively obtained composite as quasi-homogeneous, which makes it possible to simplify the calculation methods of structures and make them safer in operation. The analysis of the obtained results confirms the incorrectness of using standard methods for determining the strength indicators of additively manufactured materials when evaluating their design characteristics; the main direction for improving printing technology is the need to improve adhesion between layers; the expediency of increasing the width and thickness of tracks, which helps to reduce the number of contact zones. The proposed method is simple, accessible and does not require a special laboratory base.