19 June 2001
SR-4: REPAIRING STEEL PILE WITH CONCRETE ENCASEMENT
to moderate deterioration (less than
of the cross-
sectional area has occurred; or protection against corrosion and abrasion is
Description of Repairs: Clean the steel pile of all marine growth and loose rust
using a high-pressure water blaster. Two methods may be used to provide the
concrete encasement: flexible and rigid form. In addition, steel angles may be
used with the rigid form, to regain some of the reinforcement in the steel pile
where greater levels of deterioration have occurred (see Figure 8-4). After the
piles have been thoroughly cleaned, place a 150- by 150-mm (6- by 6-inch)
reinforcing mesh around the pile, using spacers to maintain clearance between
the pile, reinforcing, and fabric form. The fabric form should be placed around the
For the flexible form, the zipper should be closed, and the form
secured to the pile at the top and bottom with mechanical fasteners (see Figure
For the fiberboard form, the straps are installed and secured every
300-mm (12-inch). Maintain a 38-mm (1 -inch) space between the pile and
reinforcing and between the reinforcing and form (see Figure 8-4).
The annular space between the pile and the form is then filled to
overflowing with concrete grout using a tube or hose extending down to the
lowest point of the form. The form is left in place and the base is backfilled to
above the concrete.
Application: This method can be used as a repair or as a protection technique to
prevent further rusting or abrasion. The method will not restore bearing capacity
lost by the deterioration of the steel cross section. Partial restoration of
compressive strength may be gained by the using steel angles with the concrete
encasement. This is not a generally accepted practice, however, so care must be
used to ensure that the connections are made to sound metal. Many times,
posting the existing pile with a new H-pile section may be more cost effective.
Economics would normally govern the decision.
Future Inspection Requirement: Increased inspections may be required to
detect signs of potential failure of the repair.