CONSTRUCTION OF AN ULTRA-HIGH-PERFORMANCE FIBRE-REINFORCED CONCRETE THIN-SHELL STRUCTURE OVER THE MILLAU VIADUCT TOLL GATES

摘要

This paper presents the design and construction of the thin-shell structure over the Millau Viaduct toll gates. The BSI-CERACEM concrete used for this innovative structure is an Ultra High Performance Fibre Reinforced Concrete (UHPFRC), with a compressive strength of 165 MPa, in which steel fibre ensure ductile behaviour under tension and dispense with the need for traditional passive reinforcement. The design is based on a succession of identical precast segments, hollow-core thin-shell elements assembled by post-tensioning. Special experimental methods for characterizing FRC properties were used to obtain pertinent data. The project also required several test campaigns to validate the assumptions used for design and to verify the behaviour of the concrete at the scale of the actual structure.