FraQCon · Predicting fracture in 3D printed concrete beam lattice systems with the QuasiContinuum method for computational efficiency

3D-printed concrete (3DPC) mitigates CO2 emissions, provides architectural design with higher degrees of freedom and decreases both labor costs and energy consumption. However, its layer-by-layer build-up process results in weaker and more porous interlayers, thereby significantly decreasing the integrity and durability of 3DPC structures and limiting the versatility of this technology. To overcome this major drawback, FraQCon aims to develop a computationally efficient framework to understand how porosity affects interlayer bond strength and to enhance 3DPC. For this purpose, FraQCon will apply numerical beam lattice models to 3DPC because they accurately predict fracture in heterogeneous materials such as concrete and rock. Although microscale porosity analysis based on simulations of engineering-sized 3DPC structures remains computationally unfeasible, the multiscale QuasiContinuum (QC) method has efficiently reduced computational costs for lattice systems. Its current form is not yet applicable to 3DPC beam lattices, but FraQCon will develop a novel QC methodology for fracture in 3DPC beam lattice models to predict failure in a computationally feasible way while accounting for porosity on a microscale and accurately representing the complex air void morphology in 3DPC interlayers. Moreover, this QC methodology will be validated with experimental tests. By identifying key parameters that cause interlayer weakness, FraQCon will significantly improve 3DPC technologies and increase the integrity, safety, and durability of 3DPC structures. The FraQCon QC framework and the knowledge gained during this project will be transferred to a 3DPC start-up in a non-academic placement to accelerate the adoption and foster the market impact of this technology. Therefore, FraQCon will not only demonstrate the applicability of the QC method for 3DPC design but may also transform the construction sector towards automation.