Concrete 3D printing by extrusion is increasingly being studied and adopted in the architecture, engineering, and construction (AEC) industry. However, the lack of specific standards and the difficulty in ensuring the mechanical performance of both the material and the resulting structures still limit its application for structural purposes. This PhD thesis, conducted by the Navier Laboratory in collaboration with XtreeE, aims to address these challenges through an approach combining mix and structural design.

In the first part, a method for formulating printable materials based on the compressible packing model was developed. This approach enables the identification of mix designs suitable for bi-component 3D printing, potentially incorporating supplementary cementitious materials with the goal of reducing the environmental footprint.

The second part focuses on the mechanical performance of printed materials, particularly when reinforced with continuous fibers using the Flow-Based Pultrusion process developed at the Navier Laboratory. This process improves tensile strength and provides the ductility required for structural applications.

Finally, a full-scale printed thin shell, designed and dimensioned according to Eurocode 2 principles, illustrates the potential of these technologies for the fabrication of complex architectural elements.

This research is part of an applied approach oriented towards robotic and prefabricated solutions for civil engineering and architecture.