ASF manages numerous motorways in the south of France, including 57 independent-span viaducts made of prestressed beams. To audit the state of these particular structures, ASF launched a major diagnostic study.


• Geometric investigation of decks
• Radar measurements of asphalt thickness
• Opening of windows on prestressing ducts
• Videoendoscopy of the beam ends
• Videoendoscopy of the inside of prestressing ducts
• Crossbow tests on prestressing cables (LRPC Lille)
• Microscopic examinations (by SEM)
• Defining the physical characteristics of the concrete
• Defining the chemical characteristics of the concrete
• Verification of the steel coatings by radar
• Inspecting the degree and speed of corrosion on the passive reinforcements
• Defining the characteristics of the prestressing cable steel
• Taking liquid samples at the duct openings
• Taking and chemically analysing sludge samples