IMPROVING CONCRETE BOND IN REPAIRED BRIDGE DECKS

The article discusses the repairing of concrete bridge decks that should give a composite deck of at least the strength of the original deck. The strength of the composite deck depends on the bond between the old and the new concrete; the factors affecting this bond are discussed. Research in this area is discussed, and tests are described. Pull-off tests on composite concrete test slabs and on repaired concrete bridge decks show that a good bond between old and new concrete can be obtained without expensive connecting dowels if certain precautions are taken. These precautions relate to removal of concrete, cleaning of the contact surface, compaction of the concrete overlay; and the curing of the overlay.