Durability of Posttensioned Concrete After 33 Years of Marine Exposure: Fid-Bau Portal

Durability of Posttensioned Concrete After 33 Years of Marine Exposure

M. Schupack / E. F. O'Neil

To determine the most effective end anchorage protection for posttensioned beams, 20 air-entrained posttensioned beams were fabricated and placed at the Treat Island Severe Weather Exposure Station in 1961. The beams were fabricated using 4 types of posttensioning systems with 12 different types of end-anchorage protection over external and recessed anchorages. End-anchorage protection was applied to the beams using six different types of joint preparation: bush-hammering, epoxy-resin adhesive on sandblasted surface, retarding agent, sandblasted, sandblasted with primer, and no preparation. The end protections were made from three different mixtures: portland-cement, epoxy-resin concrete, and sand-cement mortar. The 20 posttensioned test beams have been inspected annually by the Corps and biennially by other interests. Eleven of the beams have been autopsied at the U.S. Army Engineers Waterways Experiment Station in 1973-74 and 1983. Now, with 33 years of exposure of nine beams and the autopsy data, this report has been prepared jointly by Mr. Morris Schupack, Schupack Suarez Engineers, Inc., and Mr. Edward F. O'Neil, U.S. Army Engineer Waterways Experiment Station. It assembles the data obtained, evaluates the data, summarizes the important findings related to durability, and makes recommendations for durable details.