Mechanical properties of extrusion-based 3D-printed concrete considering the thickness of the printed layer and printing time interval

This paper investigated the performance of 3D printed concrete with a focus on the bonding layer, considering the thickness of the printed layers. Through experimental testing and numerical simulation, the mechanical properties and failure mechanisms of the bonding layer were thoroughly analyzed. The results revealed that compressive strength diminishes with thinner layers and longer printing intervals, while anisotropic mechanical properties become increasingly pronounced with reduced layer thickness. The static performance of 3D printed concrete arches was also studied, showing that increased layer thickness enhances the ultimate load bearing capacity. Cohesive elements were used to simulate compressive strength across varying layer thicknesses and printing time intervals. Prediction formulae for compressive strength were developed and validated through experimental data. The study further simulated the static performance of arches using both cohesive elements and anisotropic material properties, confirming the accuracy of the strength prediction formulae and the effectiveness of the simulation methods.