Hydrodemolition used for viaduct repairs

Conjet has supplied a 322 Robot hydrodemolition machine and powerpack to help renovate a reinforced concrete viaduct in Torano, east of Rome, Italy.

Specialist hydrodemolition contractor, C.P.L. 2000, is carrying out the work in a joint venture with Edil C.R.R. and Global Klima.

The Viadotto Fiume Salto, which was opened in the late 1960s, is on the main E80/A24/A25 motorway crossing central Italy, between Torano and Pescara.

A spokesman for Conjet said use of de-icing salts during winter had caused calcium chloride damage to the structure, forcing the Italian Highways Authority and the Autostrada di Parchi's owner, Toto, to carryout extensive repairs.

The renovation, funded by revenue from tolls, is expected to cost around € 5 million and is focusing on the piers and main joints in the concrete deck using the hydrodemolition high pressure water jetting technique to remove the calcium chloride infected concrete.

President of C.P.L. 2000, Angelino Rinaldi said, "This is a major bridge repair project and hydrodemolition with the Conjet Robot is the only method of removing the damaged concrete.

"Using very high pressure jets of water to remove only the poor concrete does not cause any damaged to the good concrete left behind and, if necessary, it also takes away concrete from below the reinforcement, which is also cleaned of any rust.

"Using breakers would have taken so much longer and also caused damage to the good concrete left behind. Hydrodemolition with the Conjet Robot also has the advantage of producing a very rough surface, which gives a good bond for the new concrete to key onto."

To complete the concrete restoration the repaired structure will be coated with protective paint to prevent possible future attack from de-icing salt.