Auxetic lattice reinforcement for tailored mechanical properties in cementitious composite: Experiments and modelling

Abstract

This study uses additively manufactured polymeric auxetic lattice as reinforcement to develop cementitious composites with improved ductility and energy absorption characteristics. The compression performance of plain mortar along with reinforced specimens was experimentally investigated using auxetic lattices with different Poisson’s ratio. Experimental results indicate that auxetic lattices fabricated from ABS polymer exhibit lower strength and stiffness than concrete, and therefore the load-bearing capacity of lattice reinforced mortar decreases with progress in compression. Nevertheless, ductility improvement was observed due the presence of auxetic lattices. The maximum ductility improvement was approximately 100 % and 200 % at 15 % and 50 % drop in peak load respectively. The failure pattern and energy absorption capability of lattice-reinforced concrete composites (LRCC) specimens were also affected by the auxetic design and it’s negative Poisson's ratio, as the highest energy absorption at failure is nearly eight times higher than the plain mortar. The finite element results corroborated by experiments elucidate the role auxetic reinforcement in LRCC at different volume fractions. The findings suggest that the peak stress, ductility, Young's modulus, and energy absorption capacity of LRCC can be effectively tailored for various applications by tuning the auxetic lattice (reinforcement) properties.