Flexural Behavior of Bio-inspired Beams Using Ultra-high Ductile Concrete and Its Theoretical Model

Abstract:

Based on the hierarchical micro-structure of nacre， this study developed a bio-hierarchically stacking method at a macro-scale. A series of beams were fabricated using ultra-high ductile concrete （UHDC）. Uniaxial tensile and compressive tests were conducted to obtain the constitutive model of UHDC. Four-point bending tests were carried out to investigate the flexural property of the stacked beams. The results indicate that the flexural strength of directly stacked beam reaches 16.75 MPa， which is 1.34 times of that of monolithically cast beam. All hierarchically stacked beams exhibit superior deformability， toughness and energy dissipation capacity， even though the deflection/span ration reaches as high as 1/50. Moreover， interlamellar sliding and cracking branching are also observed on the hierarchically stacked beams， which are similar to the failure model of nacre. Finally， a theoretical model was proposed based on the constitutive model of UHDC and verified by comparing the experimental results and theoretical results.