초록 ▼

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 len

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 prostressing 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 corrosion condition of the prestressing element between the inlet port and the outlet port. A method and apparatus is also provided for the on-site corrosion protection of unbonded prestressing elements whereby the gaseous environments within the conduits are cyclically pressurized with a dry gas. The protection method may also include programmable control of the dry gas pressurization and feedback of the humidity levels in the conduits for adjusting the parameters of cyclical pressurization so as to maintain a predetermined maximum humidity value in the gaseous environments associated with the prestressing elements of the structure.

대표청구항 ▼

A system for on-site corrosion protection of unbonded prestressing elements on a post-tension concrete structure in service, said elements each being disposed within a respective conduit, said conduits each containing a gaseous environment to which said elements are subjected, the system comprising:

A system for on-site corrosion protection of unbonded prestressing elements on a post-tension concrete structure in service, said elements each being disposed within a respective conduit, said conduits each containing a gaseous environment to which said elements are subjected, the system comprising: (a) inlet ports provided in said concrete structure, said inlet ports being located at respective positions along the longitudinal lengths of each of said prestressing elements and between terminal ends thereof, said inlet ports respectively permitting communication with said gaseous environments in said conduits; (b) a supply for supplying site-manufactured dry non-corrosive gas through said inlet ports to said conduits, (c) an automatic controllable valve for said supply; (d) a programmable controller for actuating said controllable valve to cyclically pressurize said conduit with said dry gas provided through said inlet ports for a selected duration of time and according to a selected time schedule; and (e) access ports for accessing said gaseous environments in said conduits of a preselected number of said prestressing elements for measurement of said gaseous environments therein to determine the humidity thereof.