Details

This study focuses on improving the mechanical properties of 3D printed concrete. The goal of the study is to improve the tensile strength, ductility, flexural strength, reduce anisotropy of 3D printed concrete by reinforcing with plastic bottle fibers. A 3D nonlinear finite element model was developed to represent the 3D printed concrete specimen that captures the extruded layer, weak interlayer bond and plastic bottle fiber reinforcement. Full parametric studies was performed across fiber dosages from 0 to 3.5% with an increment of 0.5%. The results indicate that, there is an overall increase in mechanical properties with an increase in fiber content. At an optimal fiber content of 3%, compressive strength increased from 35 to 52.2 MPa, flexural strength from 5.8 to 19.1 MPa and tensile strength from 3.2 to 12 MPa. Tensile stress strain behavior of the material was transformed from brittle to ductile with a clear post peak residual strength due to fiber bridging mechanism. Toughness increased by over 300% at an optimal fiber content of 3%. Mechanical anisotropy was significantly reduced with a strength ratio (perpendicular/parallel) improved from 0.42 to 1.1 at 3% fiber content. These results were obtained through the application of advanced computational tools and information technologies, including ABACUS for finite element analysis and MATLAB for numerical calculations and post processing of data.