Investigation of Hydrophobic Concrete Additive for Seawall Replacement at Pililaau Army Recreation Center, Hawaii

Abstract : This Office of the Under Secretary of Defense Corrosion Prevention and Control Program project was to demonstrate the long-term performance of an ultrahydrophobic concrete additive that blocks water intrusion and chloride penetration into concrete. The proprietary additive was to be used to repair the seawall in a highly corrosive environment at Pililaau Army Recreation Center (PARC) in Waianae, Hawaii. The deteriorating stone seawall at PARC was to be covered in a concrete veneer with a new stair access to the beach, both using the waterproofing additive. Chloride, humidity, and corrosion rate sensors were placed in the concrete veneer panels and were to be monitored for two years. Unfortunately, while the seawall veneer panels were completed, the government was unable to obtain necessary permits to allow excavation of the beach at the base of the seawall for construction of the footing. Even after it became clear that the work could not be completed under the contract for this project, the Corps of Engineers Honolulu District in Hawaii initiated their own project to complete the work by using the prepared veneer panels, but they also were unable to do so because of the permitting and environmental study requirements.