Two pioneering works by Eugène Freyssinet listed as historical monuments
The final stages of the registration as historical monuments of two structures designed using revolutionary techniques developed by Eugène Freyssinet have just been successfully completed.
Since October 1st, 2021, the Boutiron Bridge near Vichy, FR, and the Veurdre bridge test arch in Moulins, FR, have been officially recognized and protected as historical monuments by the French Ministry of Culture.
The Boutiron bridge and the Veurdre bridge test arch, two pioneering structures
These structures were built at the beginning of Eugène Freyssinet’s career as a civil engineer, in his first collaboration with the entrepreneur François Mercier.
The Boutiron Bridge
The Boutiron Bridge was originally part of a three-bridge set. Like the other two, it benefited from a system of articulation between lightly reinforced concrete blocks. This allowed the arch to oscillate and to be unbent by jacking consequently. This new technique earned Freyssinet an award from the prestigious French Académie des Sciences in 1908. The Boutiron bridge has a unique patrimonial value as it remains the only historical witness to this day. The other two bridges (the Châtel-de-Neuvre bridge and the Veurdre bridge) have indeed been destroyed in 1940 and in 1944 during WWII.
The Veurdre bridge test arch
The test arch preceded the construction of the Veurdre bridge set in 1908. Intended as a true test of the strength of concrete, this arch with a span of 50m and a 2m deflection was a technical challenge in its own right.
In order to guarantee the accuracy of the measurements, it was necessary to contain the enormous load of the arch and to prevent the abutments from moving away. The abutments were connected under the arch by a concrete tie rod, constrained by 1,200 tensioned steel strands, applying a pressure of over 2,500 tonnes.
The arch incorporates the first beam with tensioned steel cables, making it the first pre-stressed concrete structure in the world. This iconic invention of Freyssinet was later patented in 1928.
Freyssinet and innovation: two symbolic works
Built in the early days of Eugène Freyssinet, the Boutiron bridge and the Moulins test arch are two historical testimonies to the engineer’s talents as a builder. They are also great proofs of his quest for innovation, which guided his work and, more broadly, his oeuvre.
Jacking and pre-stressed concrete are still widely used today and are considered two major innovations of the 20th century in construction.