Concrete bridge decks often show extensive damages caused by wear, de-icing salts and freeze-thaw cycles. The damaged concrete has to be removed and replaced by a new-cast concrete topping.The bonding between old and new concrete has been studied by tests with composite concrete beams. The beams were composed of old concrete with a stripped, rough interface against a new concrete topping.In one investigation composite concrete beams were loaded by a single load at the center of the beam. Both static and fatigue tests were carried out. The results show good bonding in both cases.In a second investigation the effect of differential shrinkage was studied. The composite concrete beams in the tests could resist the residual stresses caused by differential shrinkage without cracks along the rough interfaces or in any of the parts of the beams. The stress relief caused by the creep, which is simultaneous to the shrinkage, is the main cause of the resistance of the concrete beams to residual stresses caused by the differential shrinkage.
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- Bonding between Old and New Concrete in Structures Loaded by Static and Time-Dependent Load
- Springer US
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