Physical Simulation of Brittle Rocks by 3D Printing Techniques Considering Cracking Behaviour and Permeability

Abstract

Additive manufacturing, commonly named 3D printing, is more frequently studied and used due to its ability to replicate micro- and macroscopic structures in natural rocks and fabricate complex experimental samples. Previous studies in this field mainly focused on mechanical properties and cracking behaviour but less on permeability because of the difficulties in unifying these three aspects with modern 3D printing techniques. Since the plaster-based 3D printing (PP) samples are more brittle and are close to rocks, and the stereolithography (SLA) samples have a higher resolution without chemical reaction with water, the present study combined these two mainstream 3D printing methods to try to replicate both the mechanical and permeable behaviour of rocks. Stereolithography (SLA) resolution can replicate submillimetre pores and structures in natural rocks. The result is that the PP method can successfully print rocklike samples, and their strength and failure modes are significantly influenced by the printing dip angle and sintering temperature. The porosity and anisotropy of the permeability of the samples printed by the SLA method are compared with the prototype porous basalt, and the replication ability in pore structures and seepage is confirmed. In addition to the experimental study, the theoretical permeability of samples printed with various resolutions is also discussed. The results of this study demonstrate the effectiveness of combining PP and SLA 3DP techniques for physically simulating natural porous rocks.