Socotec supports the construction of a building using 3D concrete printing

3D printing techniques, by significantly reducing construction time and the strain on workers, are contributing fully to this trend. However, these innovative techniques require validation by a trusted third party to confirm that their performance complies with the requirements of various regulations.

For Julien Brunaux, Director of the SOCOTEC Construction & Real Estate Agency in Reims: "We are very proud to be taking part in this project, which perfectly illustrates the role our technical expertise plays in supporting and facilitating innovation. SOCOTEC had already supported Plurial Novilia on the first Villiaprint© project, so it was quite natural for our teams to join forces with this new challenge."

Housing printed in a few weeks

Based in Reims, the social housing provider Plurial Novilia, a subsidiary of the Action Logement group, has set itself the mission of revolutionizing social housing using 3D concrete printing construction techniques. This technique should ultimately reduce construction time and the arduousness associated with construction. The first Viliaprint© project, initiated in 2018 and completed in June 2022, was a successful first attempt, with the construction of 5 pavilions whose non-load-bearing walls were 3D printed in concrete at the Rungis factory and assembled on site in Reims.

With the ViliaSprint² project, Plurial Novilia has taken on an even more ambitious challenge: this time, the project involves a two-story building whose entire supporting structure will be 3D-printed in concrete directly on site. This project represents a major innovation on a European scale, and is the largest 3D-printed apartment building on the continent. With an average width of 10 meters, a length of 30 meters, and a height of 9 meters, each floor has a gross floor area of ​​300 m², totaling 800 m² of living space for the entire building.

For example, in terms of speed of execution: a printed floor is assembled in 4 weeks, while a month and a half is necessary with traditional construction methods.

To achieve this performance, directly on site, the 3D concrete printer unrolls and gradually stacks high-performance concrete cords. Each wall is thus composed of an outer skin of 8 cm and a double inner skin of 16 cm, the gap between these two thicknesses is filled with a durable insulation.

Supervise the implementation of an innovative process

Construction methods using 3D concrete printing have not yet been the subject of any regulatory framework. SOCOTEC's role is to confirm that all the performance characteristics of the future building are at least equivalent to those of a traditional construction. SOCOTEC experts were therefore involved from the early stages of the design process, validating technical points as they progressed, in coordination with the teams from the design office, the company carrying out the printing, the acoustician, the technical office, etc. The analysis focused in particular on structural, acoustic, thermal, and fire stability aspects.

SOCOTEC teams ensured the concrete's thermal performance and carried out optimizations so that the buildings had very good inertia, in line with the RE2020 objectives. In order to test the fire resistance of the walls, laboratory tests were carried out on the concrete, which has the particularity of not being reinforced. A Technical Experimental Assessment (ATEX) file was then validated by the Scientific and Technical Center for Building (CSTB).

The role of SOCOTEC experts continues on site, monitoring and validating the correct implementation of the process and the performance of the building as it progresses.