Self-Compacting Concrete for the Durable Reinforced Foundations of the Calatrava Bridge in Venice
Mario Collepardi, Silvia Collepardi, Ettore Menegaldo and Roberto Troli
Appears on pages(s):
durability; limestone filler; self-compacting concrete; superplasticizer; viscosity modifier
The present paper describes the building of the Fourth Bridge on the Grand Canal in Venice, designed by the Architect Santiago Calatrava. In particular, this paper is devoted to the laboratory and field tests to develop the composition of a self-compacting concrete (SCC) to be placed in the congested reinforced foundations of the Calatrava Bridge. To ensure a durable service life of at least 100 years, a water-cement ratio as low as 0.45 was adopted due to the contact of the reinforced foundations with the seawater. The placement of the SCC was carried out in only a few hours of a night to reduce the interruption of the ferry traffic in the Grand Canal. The concrete was pumped from truck mixers, all located on the Rome Square side of the bank of the Grand Canal, and feeding the fresh mixture in both the reinforced spaces devoted to the foundations. The reinforced foundations are exposed to a significant load due to the heavy weight of the bridge manufactured of steel and glass, as well as to the shear stress caused by the peculiar shape of the bridge characterized by a segmental arch. Due to these factors, some cracks were observed every year on the top of the foundations. This means that in the next future some measures should be taken to block the formation of new cracks. Meanwhile, the already formed cracks have been sealed and protected by an upper coating stone in order to inhibit the ingress of the airborne swept by the wind from the close sea water causing the corrosion of the metallic reinforcements promoted by the presence of chloride ions.