Numerical modelling strategies for reinforced 3D concrete printed elements

Extrusion-based 3D concrete printing (3DCP) prompts a new age of reinforced concrete structures by virtue of the exponential advancements in process, control, material, and fresh-state analysis technologies. Notwithstanding these advancements, latency exists in the numerical analysis of complex geometric forms produced by 3DCP technology. In this research, two finite element (FE) modelling strategies are proposed for the numerical analysis of 3DCP building elements. The objective of these models is to predict the hardened state structural capacity and failure mechanisms of singularly and dually reinforced concrete deep beams under various loading configurations. To validate the proposed FE modelling strategies, the reinforced 3DCP deep beams are experimentally evaluated. An analogy between masonry and 3DCP structures provides premise to the presented FE modelling strategies, and succinct descriptions of the respective modelling strategies, adaptions to the 3DCP design space, and material model prescriptions are provided. Strikingly, the recommended input parameters provide sound agreement with the experimentally evaluated configurations, with all simulations exhibiting a load carry capacity within 14% of the experimental observations. Not only is the load-displacement response deemed appropriate, but also the numerically produced cracking patterns, placing confidence in the proposed numerical simulation strategies. Furthermore, it is shown that the advent of a 2D plane stress simplification of the fibrereinforced hollow beam geometry yields adequate agreement while significantly reducing the computational expense required to simulate the nonlinear response of anisotropic printed composites.