|TO:||All Design Staff|
|DATE:||July 28, 1995|
|SUBJECT:||Maximum Size of PT Tendons|
The Standard Specifications indicate that the maximum size PT Tendon shall be 31-1/2" strands or 22-0.6 strands. Recently, there have been a few PT Tendon shop drawings approved with a tendon size larger that specified. I have asked Ralph Dornsife to modify the BDM to make the shop plan review process clearer.
In the interim, the following design policy should be followed:
- The maximum size of a PT Tendon should be 31-1/2" strands or 22-0.6 strands. Use of a larger tendon requires the approval of the Bridge Design Engineer and the Design Unit Supervisor.
- PT shop drawings received that detail a PT tendon larger than the specified maximum should be "Not Approved" with a note indicating that "the tendon sized exceeds the maximum tendon size specified in the contract".
This design policy will result in better distribution of the post-tensioning force in the concrete section, with a minor effect on overall cost of the bridge.
cc: J. A. Weigel, 7354
F. Higgins, 7340