3D-printing with cement-based materials has gained attractiveness in recent years thanks to freedomofformallowingformasscustomization,aswellasreducedmaterialconsumptionthrough shapeoptimization. However,reachingrepeatablequalitystandardsandpredictablemechanicalprop- erties for print pieces remains a challenge which modelling could help solving. We thus propose a simulation framework for 3D-printing of cement-based materials with two…
3D-printing with cement-based materials has gained attractiveness in recent years thanks to freedomofformallowingformasscustomization,aswellasreducedmaterialconsumptionthrough shapeoptimization. However,reachingrepeatablequalitystandardsandpredictablemechanicalprop- erties for print pieces remains a challenge which modelling could help solving. We thus propose a simulation framework for 3D-printing of cement-based materials with two main components. Firstly, we present a fully coupled thermo-hydro-mechanical constitutive model, extended from classical poromechanicstochemicallysolidifyingmedia, whereinmaterialproperties evolve with the extent of hydration reactions, allowing to cover behaviours from the very-early age to the hardened state, along with some experimental procedures to determine model parameters. Secondly, a finite element-based modelling strategy is introduced, aimed at creating a digital twin of the printing process, namely the sequential deposition of the material throughout the print path. Such a framework allows the inves- tigation of common issues in 3D-printing of cement-based materials along with their multi-physics origins, ranging from printing failures to longer-term durability concerns. Influence of process-related parameters -such as layer-pressing- and environmental conditions on printing stability and accuracy are displayed, along with indication as to their mitigation. Durability issues related to drying, be it at the interlayer or at the exterior surface of a print piece, are also presented in light of a detailed modelling of unsaturated behaviour from the constitutive model.