Venetian Condominium
Services Applied by VCS Engineering
Project Introduction
The Venetian Isles Condominium in Naples, Florida, was built over Inner Doctor’s Bay. The building is supported on over 500 14-inch square precast reinforced concrete piles directly exposed to an aggressive coastal marine environment. Previous inspections of the piles have observed the beginnings of corrosion deterioration in the form of cracked, delaminated, and spalled concrete. The Venetian Isles Condominium Board of Directors requested that Vector Corrosion Services (VCS) perform a corrosion evaluation of the piles to determine if any corrosion mitigation solutions were warranted.
Project Scope
The focus of VCS’s testing was on a small sample of 20 waterside piles. VCS selected these 20 piles based on their condition reported in a previous visual inspection. This report indicated most of the piles selected by VCS (16 piles) as damaged. The four remaining piles had no indication of deterioration and were used as a baseline for comparison. VCS selected ten piles each from the north and south sections of the building.
VCS performed the following testing on each of the selected piles:
- Visual and sounding inspection to determine the extent of physical deterioration
- Measurement of the in-place cover depth for the pile reinforcement using ground penetrating radar. The cover-depth was used in the assessment of risk for corrosion activity due to chloride exposure
- Determination of electrical continuity of the reinforcement to determine if cathodic protection would be a viable rehabilitation strategy
- Corrosion potential survey to determine the extent of active corrosion
- Collection of concrete samples for chloride concentration testing. Samples were collected at the reinforcing steel's depth to determine the corrosion risk.
Project Solution
Overall the condominium’s piles were in relatively good physical condition; however, chloride exposure at the steel depth was severe and in high enough concentrations that there was a very high risk for activation of corrosion. In some piles, corrosion had already been initiated, as identified by the corrosion potential survey. The sounding inspection located delaminated concrete on several piles due to corrosion activity. The condominium had previously conducted patch repairs of several delaminated piles and in almost all instances, these repairs were failing because of the severity of the corrosive environment and lack of proper repair procedures.
Based on the condition of the piles, VCS developed a rehabilitation strategy that would implement galvanic cathodic protection jackets. These jackets would provide a protective current to the pile reinforcement to stop active corrosion and prevent corrosion from occurring in the future. VCS developed a multi-year rehabilitation strategy that would address the worst piles first and then over time address more piles based on their risk for corrosion. This provided a cost-effective solution to the condominium allowing them to budget a long-term rehabilitation. VCS developed a design for the jackets, which went to bid and was awarded to a local contractor. VCS supported the owner during installation in a quality control role to verify the contractor followed the project drawings and specifications.