Three-dimensional (3D) concrete printing (3DCP) is an emerging construction technology that differs fundamentally from traditional cast-in-place methods. Its formwork-free process substantially reduces both material and labor costs, thereby broadening its application potential. This study introduces a bidirectional reinforcement strategy for 3D printed concrete (3DPC) structures using stainless steel wire mesh. Gradient-reinforced specimens with varying reinforcement ratios were designed to identify the optimal reinforcement configuration. Specimens were prepared for compression, tension, and three-point bending tests, incorporating wire mesh spacings of 4, 6, and 8 mm and wire diameters of 0.5, 1, and 1.5 mm, resulting in nine reinforcement combinations. The mechanical performance of these configurations was evaluated along the stacking direction and compared with that of unidirectionally reinforced specimens. The results indicated that Specimens C-1.3, T-1.3, and F-1.3 exhibited the lowest load-bearing and deformation capacities. In contrast, Specimens C-3.2, T-3.2, and F-3.2 achieved load-bearing capacities similar to those of C-3.1, T-3.1, and F-3.1, with C-3.1 and F-3.1 showing marginally higher values. This suggests that increasing the reinforcement ratio improves both strength and deformability. Moreover, Specimen T-3.2 demonstrated superior flexural strength compared with T-3.1, a trend also observed in T-2.2. Additionally, in comparison with specimens reinforced only in the longitudinal direction, the bidirectional reinforcement method significantly enhanced the load-bearing and deformation performance of 3DPC structures. These findings confirm the feasibility and effectiveness of the proposed bidirectional reinforcement approach in improving the strength and toughness of 3DPC.
Nan et al. (Wed,) studied this question.