Design and production of a 3D printing marine ecological structure

This article discusses the use of 3D printing technology for hydraulic cementitious binder-based materials in ecological marine construction. More specifically, it looks at the architectural, environmental, technical and economic performance that this technology can bring to the construction of artificial reefs and coastal erosion control systems, as well as the eco-design of port structures.

The use of mixed 3D-printed and reinforced concrete structures makes it possible to create structures with superior ecological and technical performance, even unattainable with conventional reinforced concrete prefabrication methods, improving the environmental footprint of construction while remaining within a framework of economic feasibility.

The adaptation of design and construction to 3D printing will be illustrated through the presentation of a project to design/build a large-scale marine artificial reef as part of the RECIF'LAB Future Investment Program carried out between 2018 and 2021 in collaboration with the town of Agde.

The innovation presented focuses in particular on the development of an iterative and efficient design methodology for dimensioning the hydrodynamic stability and structural strength of mixed 3D material/reinforced concrete structures in the marine environment, with high hydrodynamic thrust forces and a particularly demanding chemical composition for the reinforced concrete, leading to a risk of corrosion of the reinforcement and chemical and biological attacks on the concrete.

Last but not least, the construction and deployment of the structure were also innovative, with major challenges in terms of monitoring manufacturing quality, establishing a phasing and methodology to guarantee technical feasibility, and finally handling operations on land and at sea to enable deployment in open seas over 3 nautical miles away and at depths of over 20 m.