Study on flexural properties of 3D printing functionally graded lattice structure cement composites

Concrete is widely used in construction due to its superior performance but has limited ductility. This investigation aims to enhance ductility by incorporating 3D-printed polymer-reinforced cement composites. We explored functionally graded triply periodic minimal surfaces (TPMS) lattice structures, fabricated using photocuring 3D printing with ABS-like resins in a cementitious matrix. These lattice structures feature varying relative densities for optimized toughness. Three-point bending tests and digital image correlation (DIC) revealed notable enhancements in flexural properties and crack resistance. The Gyroid50-30 structure increased flexural toughness by 88.6% compared to normal cement mortar. Gyroid60-20 and Gyroid40-40 groups, with different density gradients, showed improvements of 499.2% and 389.8%, respectively. This research suggests that tailoring lattice shape and density gradient can effectively optimize flexural performance.