Post tension corrosion due to water intrusion has become an increasingly widespread problem among parking structures, high rise buildings, and slab on grade applications. The problem stems from the fact that the process for sealing these pocket ends does not translate well from paper to practice. It is nearly impossible to roughen the glass like interior of the pocket with a wire brush. Furthermore, retempering the grout mix leads to skewed W/C ratios and an inconsistent mix. Finally, bonding agents are used only when readily available and are often used incorrectly.
To counter these problems, we invented the Post Tension Plug system. This 2-part system insures that a watertight seal is achieved at every pocket. The custom sized reaming tool roughens and decontaminates 1/16" off the inside of the pocket (without touching the grease cap). After the dust is removed, the precast plug which is made of a high strength non-shrink grout is designed to fit securely into the pocket after a coating of epoxy has been applied. The Post Tension Plug is 1.25" thick with a .25" recess. This ensures that the 1" of coverage stated by ACI and PTI is met every time. Additionally, this ensures that the cable must be cut correctly and the grease cap must be properly seated. If the Post Tension Plug does not fit flush with the slab’s edge, there is a problem with the cable or grease cap (a built-in quality control program).
- Water cannot enter the pocket
- Minimizes the risk of post tension corrosion
- Minimum coverage of 1” is met every time
- Grease cap must be properly seated for system to work
- Decontaminates area of grease, dirt, and dust
- Complies with ACI 301-10, MTI M55.1-12, and ASTM C 1107
- Best defense in aggressive coastal environments
- Zero waste and zero shrinkage
How you benefit Imagine completing a project and completely walking away. No phone calls for comeback work and no legal issues with building deficiencies or corrosion. With the Post Tension Plug system, contractors can rest easy knowing that no water is entering at the tendon’s stressing end. When the integrity of the building sits only 2” inside the slab, does is really make sense to just throw grout in the pocket? No, it doesn’t.
Post tension tendon repairs usually cost $4,000-$6,000 depending on length, location, and difficulty of repair. To provide a gauge of how costly these repairs can become, imagine a typical 20-story building with 5,000 tendons. If water reaches and corrodes only 1% of those tendons, you would be on the hook for $200,000-$300,000 in repairs. Are your patch guys doing their job perfectly 99% of the time? The Post Tension Plug eliminates water intrusion.
Post Tension Plugs