High Performance Concrete in the Arch of the Bridge Over the Rance
The decision to build the Rance arch bridge of high strength concrete was a successful one in a context made difficult by the geometry of the structure and the special conditons of concreting by cableway. The total duration of the work, including setting up, will be thirty months, including about ten months for the casting of the high strength concrete arch. At the start of the work, the contractor encountered some deviations from the findings and results of the concrete studies. There is reason to believe that the origin of these discrepancies lies mainly in variations in the basic component materials, on which the concrete depends. For the prepartion of the high performance concrete alone, the site set up an Arbau Euro 55 batching plant equipped with a 1-m3 vertical shaft mixer and level 3 accessories, with special arrangements for the storage and precise proportioning of the silica fume, admixtures and water.