| Location: Alaska
Built in 1972, this pier is located at the base of Pillar
Mountain in the inner harbor of Kodiak, Alaska. The original pier
is supported by reinforced concrete pier caps atop vertical steel pipe
piling and battered H-piling.
In September 1996, a condition survey revealed significant
deterioration of the concrete pier caps and several precast deck panels
which make up the pier deck. Large cracking and significant spalling
was observed along with corrosion product (rust) stains and efflorescence
near the cracks and spalls.
Because of its specialized expertise in the evaluation
of concrete structures involving corrosion and other durability problems,
WDP was retained as a subconsultant to conduct a corrosion evaluation of
the pier. The evaluation and testing conducted consisted of detailed
visual observations, nondestructive testing (impact-echo) to locate and
determine the extent of any hidden structural damage, chloride ion content
testing, and half-cell corrosion potentials.
The purpose of the chloride ion testing and half-cell
corrosion potentials was to determine the nature and extent of any on-going
corrosion of the reinforcing steel. WDP’s testing and evaluation located
significant areas in which the concrete was delaminated due to corrosion
of the reinforcing steel. Additionally, the results of the corrosion
evaluation indicated that the majority of the concrete cover on the pier
caps and precast deck panels was critically contaminated with chloride
ions and thus highly susceptible to future corrosion.
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Client: Engineer
Repair options were presented. The final repair
option employed involved the removal of contaminated concrete and replacement
with concrete containing a corrosion inhibitor. In addition, an impressed
current cathodic protection system was employed to protect the structural
steel piles.
Services WDP used on this project included:
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Structural Analysis
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Repair Recommendations
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Corrosion Investigation
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Half-Cell Potentials
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Corrosion Rate Measurement
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Chloride Ion Content Testing
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Nondestructive Testing
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