The purpose of this installation was the exposure testing of end anchor ages and end-anchorage protection for several types of posttensioning. In June 1961, 20 posttensioned beams (nominal size: 10- by 16- by 96-in.) were installed at half-tide elevation. In 1973 and 1974, eight beams were returned to the laboratory for autopsy and testing.Three beams were returned in 1982.
Data collection on this program was discontinued after 1979. Each beam contained one stressed steel tendon and other reinforcing. The beams represented four typical posttensioning systems, and the tendon in each beam was stressed in accordance with recommendations for the particular system. The tendon in 19 of the 20 beams was pressure-grouted after posttensioning. Twelve types of end-anchorage protection were used with either flush or external anchorages. The end-anchorage components of all beams were provided with 1½ in. of cover. This cover consisted of either air-entrained concrete, sand-cement mortar, or epoxy concrete. This program of investigation was conducted in cooperation with the Reinforced Concrete Research Council, and the test beams and variables were designed in accordance with their recommendations. The principal conclusions to date are the following:
a. The nominal ¾-in. cover over the conventional reinforcing is not sufficient for this exposure.

b. The flush anchorages appear to have been more effectively protected than the external anchorages.
c. Epoxy-resin concrete appears to be superior to portland-cement concrete.
d. The grease-filled paper conduit provided less than adequate protection to the posttensioning tendon for the particular exposure and test conditions of this investigation.
e. After 25 years of exposure, the posttensioning strands protected by grout-filled conduit showed no structural damage due to the environment or exposure conditions. f. Seepage through the ends of the beam was not responsible for all the oxygen and water that reached the strands and caused corrosion. Furthermore, since rust was found in the joints of the individual sections of the conduit, the ingress of water and oxygen occurred here also.g. There were not enough chlorides present in the grout to be the main factor that caused the corrosion on the strands.
h. The water that caused corrosion to the strands was due to excess mixing water present in the grout when it was pumped into the conduit and not to seawater that seeped into the conduit.
i. A galvanic current was set up between the two different concentrations of salt in the concrete and grout, thus producing the mechanism necessary to destroy the passivating film on the steel.