The effect of printing direction on strength of 3D printed concrete

This paper presents experimental results on the influence of printing directions on the strength of 3D printed concrete (3DPC) using materials available in Vietnam. The experimental results show that the printing direction has a significant influence on the strength of 3DPC with and without fiber, in which the X-direction printing samples has the lowest strength, only about 30-40% of the compressive strength and 20-30% of the flexural strength of the casted samples. However, the strength of the samples in the Y and Z directions is higher, for example, about 60 - 70% of the compressive strength and 40 - 50% of the flexural strength of the casted samples. The addition of fiber enhances the strength of 3DPC, especially with higher fiber contents, and reduces the anisotropy in flexural strength of 3DPC at a later age, i.e. 28 days.