wsdot1b1.gif (2812 bytes)


TO: All Design Staff
FROM: Chuck Ruth
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:

  1. 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.
  2. 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