Novel Compressive Constitutive Model for 3D Printed Concrete

3D concrete printing (3DCP) is emerging as a promising technology in the construction industry. From the engineering and architectural point of view, the use of 3DCP offers a great potential in terms of enhancing construction automation, more freedom of shapes and a substantial reduction of manufacturing costs associated with production and materials. Unlike traditional poured concrete, 3DCP is a layer-to-layer based manufacturing method. Such productive method makes concrete to present a layer-based structure than can lead to an anisotropic element because of the varying properties on the different spatial directions of the material. Consequently, and given the specific manufacturing method and the internal structure of 3DCP, a new approach in terms of constitutive models for design purposes is required. The objective of this is study is to develop a novel constitutive model for compression considering the influence of the anisotropy of the material. For this, an experimental program involving the characterization of 3D printed concrete specimens was conducted. The compressive strength and the modulus of elasticity was determined to obtain the stress-strain diagram on different loading directions, taking into account the influence of the layer-based structure of 3DPC. The results revealed no significant differences between spatial directions given the great homogeneity of the 3D printed concrete in all directions. However, such approach becomes necessary so engineers and designers can fully take advantage of the material and remain on the safe side of the structural design.