Mechanical properties of 3D printed concrete components: A review

3D printing, which allows components to be fabricated in layers directly from a digital file, has been increasingly used in the construction industry. However, the deficiencies in mechanical properties of 3D printing concrete (3DPC) confined its wide usage in bearing structures. The 3DPC components have the disadvantages of geometric defects, residual stress, and a high level of anisotropy, resulting in printed components with poor load-bearing capacity. Studies have been conducted to enhance understanding and control of the mechanical properties of 3DPC, aiming at promoting the application of 3DPC in structural components. This paper summarized and analyzed the related research from the perspective of the kinds of structural components, i.e., beams, columns, and walls, and discussed the effects of reinforcement methods and various factors on their mechanical properties. Finally, the current main challenges and directions of future work required to optimize the usage of this technology in 3DPC components have been identified.