The Jamor P/T Grouting System (US Patent No.: 5,540,030/Canadian Patent No.: 2,137,051) was developed to provide an economical way to protect and extend the useful service life of unbonded post-tensioned structures built in the 1960’s, 1970’s and early 1980’s that are now experiencing distress and failure. Corrosion of the cables is caused by infiltration of water and salts into the void between the steel cables and the sheathing or duct.
These unbonded post-tension systems were typically fabricated using paper or plastic sheathing with grease applied to the steel cables to reduce friction during the stressing operation and to provide some protection against corrosion.
The Jamor P/T grouting System is a proactive method of protecting unbonded post-tensioned cables. It is much more economical than cable replacement and waterproofing. The System provides the following benefits to the owner of a post-tensioned structure:
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Corrosion of the cables is dramatically reduced since the void between the plastic or paper duct is completely filled with a urethane resin, thereby preventing air and water from coming in contact with the cable. |
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The grout provides sufficient bond (resistance) that if a cable is cut or broken, the pre-stress force will be dissipated slowly enough that the cable will not erupt from the concrete. |
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The grout has been designed to allow for the removal and replacement of the cable if necessary. |
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Since the cables are protected directly by the grout, there is no need for the installation and maintenance of waterproofing systems to prevent water from entering the sheathing. |
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In most cases, the cost of the Jamor P/T Grouting System is less than half the cost of cable replacement and waterproofing. |
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P/T Cable Eruption
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Porting of P/T cables prior to grouting
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Injecting unbonded post tension cables
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