Enhanced shear performance of nacre-inspired masonry structure: Experiment and theoretical model

Unreinforced masonry (URM) structure consisting of bricks and mortar suffers severe damage under impact loading, owing to its poor ductility and brittle failure modes. However, natural nacre with a similar structure to that of masonry exhibits superior mechanical properties through the well-designed assembly process. Therefore, a nacre-inspired design method, which hierarchically assembled bricks and engineered cementitious composites (ECC) into novel masonry walls at the macro-scale, was proposed in present study. The variations of the bionic measurements were experimentally explored. Test results demonstrated that the ductility and toughness of the novel masonry structure were dramatically improved by replacing mortar with ECC as horizontal joint and setting artificial local separations. The energy absorption of masonry wall and masonry beam were improved 5.66 times and 8.05 times, respectively. A theoretical frame model for hierarchically-assembled masonry was established, which considered the randomness of masonry and simulated the crack propagation. Finally, a numerical verification was conducted based on the frame model. This study lays the groundwork for applying the nacre-inspired design method in masonry structure to improve its shear properties in terms of ductility and toughness.