Durability of post-tensioning grout systems with mixed-In chlorides

Abstract

One of the most important properties of concrete and grout is its ability to protect the structural steel that is essential to post-tensioned concrete. The purpose of this report is to determine the effect of various concentrations of chloride ions on the long term durability of pre-stressing strands embedded in grout. To achieve this objective, samples were created to mimic portions of a post-tensioned duct. Each duct was given a unique combination of chloride and water that would create an ideal environment for corrosion to take place. With the results of testing to date, it is clear that the amount of chloride is the only variable that was tested that had a significant effect on the rate of corrosion. The amount of water and characteristics of the specimen had a few trends but nothing that would lead to the conclusion that they play a significant role in the rate of corrosion.