It is essential that all of the unsound concrete be removed. The use of a hammer will be necessary to sound tight areas and the use of a sounding chain will speed up deck sounding. The practice of removing additional sound concrete after the deteriorated material is removed helps us ensure that we have a stable surface to pour against.
Special attention should be paid to the locations at the edges of the patch where the reinforcing steel enters the sound concrete. In many cases during the removal process the reinforcing steel is vibrated or impacted which causes cracking around the reinforcing steel penetration point. If this occurs, the Contractor will have to “chase” the cracks to make sure all fractured concrete is removed.
It is very difficult to get proper consolidation of a vertical patch. It may be necessary for the Contractor to utilize a “pencil” vibrator and/or externally vibrate the forms to assist in consolidation. In all cases the Contractor is responsible to provide a well consolidated patch.
Make sure that all form ties and form attachment points in both the new concrete as well as the existing sound concrete are repaired after formwork removal.
1. Document that patch a depth of 4 inches (10 cm) in achieved for horizontal patches, and a depth of 3 inches (8 cm) for vertical patches as per 519.03
2. Patch area thoroughly cleaned with water, compressed air, etc.
3. Concrete testing data and batch tickets for Class S concrete
4. Exposed area of patch given a rubbed finish and cured as per 511.17
5. Sound patches before final acceptance
6. Measure length and width for pay