Bond Behavior of Auxetic Bars in Reinforced Concrete – A Numerical Study



The study aims to enhance the bonding strength in reinforced concrete using a novel Auxetic Tubular Deformed Rebar (ATDR). A high-resolution non-linear finite element model was developed to perform numerical analysis of pull-out tests (PoT). Two sets of numerical simulations were conducted: one to replicate the concrete behavior under compression and tension tests, and the other for PoT, validated with experimental and numerical data. Numerical tests utilized a microplane model with plasticity–damage, regularized by an implicit gradient. Auxetic geometry involves adding ellipsoidal orifices to the rebar surface. Comparing the behavior of ATDR with the conventional rebar, we observed an increase in the negative value of Poisson's ratio, resulting in higher normal and shear forces, enhancing adherence. This study presents the first comprehensive simulation of Auxetic Metamaterial Rebar in concrete, offering a promising approach to enhance bond strength. Further research, both numerical and experimental, is essential to assess Auxetic Reinforcement's mechanical behavior in diverse structural elements and load scenarios.