19 June 2001
CR-4: MISCELLANEOUS REPAIRS TO CONCRETE PILES
Problem: Concrete pile is worn from abrasion at waterline; has spalled areas
above the tidal zone; or is badly cracked.
Description of Repairs: In all cases, the repair area must be cleaned thoroughly
of marine growth. All loose and deteriorated concrete must be removed. If
reinforcing steel is exposed, it must be cleaned of all rust and scale and exposed
at least 2.5 cm (1 inch) clear all around.
Figure 7-5 illustrates:
Wrap pile with spiral reinforcing length of jacket.
Place form around pile (metal, fiberglass, fiber, or other
Fill form with 35 MPa (5000 psi) concrete, either pumped or
placed with a tremie (see CPM-5 and CPM-6).
Form may be removed or left in place.
Patch Spalled Areas: Repair the spalled areas by hand (see CPM-1) or form
Fill Crack with Urethane Grout: See repair CR-1.
: The concrete jacketing repair
is a partial restoration
when the pile
is worn/deteriorated only in the tidal zone and sound below and above water.
See repair CR-5 for more complete concrete pile restoration.
The spall patching and crack filling repairs are relatively minor, inexpensive
techniques to protect the reinforcing steel from seawater. The effectiveness of
the spall patches depend on the bond that is obtained with the old concrete and
the corrosion activity on-going in the rebar in the substrate.