Viscoplastic Modeling the Evolving Mechanical Properties of Shotcrete 3D Printing Material (2026-03)¶

In recent years, additive manufacturing in construction (AMC) has gradually influenced the building industry by offering a faster and more efficient way to build with concrete. Unlike traditional methods that rely on molds, AMC deposits material layer by layer through an automated process, enabling new possibilities for custom designs and complex geometries while optimizing resource use and bridging the gap between design and construction. To fully exploit these advantages, AMC requires appropriate modeling of both the material behavior and the deposition process. This work presents a viscoplastic material model for the shotcrete 3D printing material, which serves as a foundation for simulating bulk-deposit AMC concrete and developing a homogenized substitute model. The model is based on Norton's overstress and incorporates Bingham-type rheology to capture the thixotropic behavior of freshly printed shotcrete. Numerical examples on the material point level are provided to demonstrate the transient response of the model. In addition, a boundary value problem is investigated to showcase the development of plastic failure within an AMC structure. The model's limitation regarding mesh dependency is also highlighted and a remedy is proposed.