Additive Manufacturing of Geocells: Technological, Mechanical and Micro-Structural Aspects

Additive manufacturing of honeycomb shaped geocells using fused deposition 3D printing is explored in this study. The freedom to customize the strength and surface features of geocells is utilized through 3D printing of low-strength polypropylene sheets and ultrasonically welding them to manufacture interconnected networks of geocells. The processes involved and the optimal selection of printing parameters and welding time are discussed in detail. Through tensile strength tests and interface shear tests on polypropylene sheets and junction peel tests and junction shear tests on geocell connections, important information regarding the surface features of the geocell material and its mechanical strength were obtained. Further, results from triaxial compression tests on unreinforced sand and sand reinforced with 3D printed geocells were analysed to quantify the confinement effect of the 3D printed geocells. The 3D printed geocells remained intact without any damage, up to the tested axial strains of 20%. Microscopic images of untested and tested geocells showed that sand particles got entrapped into the surface of the geocell, thus improving the interface response and in turn the shear strength of the sand. The study confirms the applicability of 3D printing technology for manufacturing customized geocells.