Extrusion-based 3D-concrete-printing with different flow direction

•The influence of flow direction on the material mass distribution, deformation behavior and interlayer bond strength of printed structures were investigated.•The effect of flow direction on the pressure gradient distribution at the outlet of the nozzle was investigated.•The relationship between the area ratio of the printed filament, compression zone volume and the compression pressure were studied. Various flow directions are employed in the actual printing process, resulting in different printed results. This study primarily investigates how flow direction impacts the distribution of material mass, deformation behavior, and interlayer bond strength in printed structures. The results indicate that flow direction plays a pivotal role in regulating printing pressure. Increasing the flow direction can lead to higher deformation ratios, improved interlayer bond strength, elevated average compression pressure, and increased printing pressure in printed structures. However, this comes at the cost of reducing the area ratio of deposited filament. Achieving a balance between high buildability and desirable interlayer bond properties solely by adjusting the flow direction during the extrusion-deposition process may prove challenging. This study provides a theoretical basis and technical guidance for the selection and adjustment of flow direction in 3D printing process.