Compressive behaviour of mortar panels reinforced with polymeric auxetic lattices: Experimental testing and numerical modelling

This paper examines the compressive performance of composite cement-based mortar panels embedding polymeric auxetic lattices, through both experimental testing and numerical modelling. In the experimental phase, lattices measuring 200 mm × 200 mm × 30 mm are fabricated using three-dimensional (3D) printing technology with Polyethylene Terephthalate Glycol (PETG) in four different auxetic geometries: re-entrant, tetra-anti-chiral, missing rib, and double arrowhead. Plain mortar specimens (panels) and those embedded with conventional non-auxetic honeycomb (hexagonal) lattices are prepared and tested to provide a comparative baseline against the mortar-filled auxetic lattices. The test results reveal that the auxetic reinforcing lattices significantly enhance the compressive characteristics of the mortar panels. On average, the peak load, toughness, and ductility ratio increase by 10 %, 1400 %, and 170 %, respectively; however, the initial stiffness is reduced by about 50 % compared to the plain mortar counterparts. A Finite Element (FE) model is developed and validated against the experimental data. The model is then employed as a virtual laboratory unit to investigate the performance of various Lattice-Reinforced Cementitious Composite (LRCC) panels with conventional construction materials (steel and normal-strength concrete).