Designing ductile, tough, nacre-inspired concrete member in metric scale

Abstract Concrete is the main material for building the largest artificial objects in the world, but suffers from brittle damages from the beginning of their existence. Natural creature, e.g., nacre, has long developed the ability to assemble brittle inorganic materials into advanced structures with exceptional mechanical property. The authors propose design motifs and principles for improving the mechanical performance of concrete member by extrinsic toughening and nacre-inspired hierarchical assembly. A theoretical model is established to trigger multiple cracking, crack branching, and deflection, and thus induce interlamellar sliding and strain relaxation to enhance damage tolerance and ductility. The results indicate that the nacreous-like concrete member can be easily fabricated using 3D printing technology, and the simple process results in metric-scale concrete member with significantly enhanced mechanical properties including strength, energy dissipation, ductility, and toughness at a new level. Moreover, it is revealed that such enhancements are closely associated with limited interlamellar sliding and strain relaxation from the hierarchically assembled structure.