Corrosion condition evaluation and corrosion protection of unbonded post-tension cables in concrete structures

Abstract From the Canadian patent

There is disclosed a method and apparatus for the corrosion condition evaluation of unbonded prestressing elements in post-tension concrete structures. The method involves locating a prestressing element in the structure and providing at least two openings in the structure at positions along the length of the element. One of the openings is an inlet port and the other is an outlet port, each of the ports permitting communication with the gaseous environment within a conduit surrounding the prestressing element. The gaseous environment is accessed through the outlet port by extracting a sample of gas therethrough. The sample is then measured to determine its humidity and thereby evaluate the …