Comprehensive Design Example for Prestressed Concrete (PSC) Girder Superstructure Bridge

3. Flow Charts

Determine the stress limit immediately prior to transfer in the prestressing strands for the prestressing steel used (S5.9.3) (Design Step 5.4.2)
Determine Instantaneous Losses (S5.9.5.2) for pretensioned members, only Elastic Shortening (S5.9.5.2.3a) is considered (Design Step 5.4.3)
Will the lump sum method or the refined method for time-dependent losses be used?

LUMP SUM go to 4

REFINED go to 8

Determine the lump sum time-dependent losses (S5.9.5.3)
Determine relaxation loss at transfer (S5.9.5.4.4b)
Determine time-dependent losses after transfer as the total time-dependent losses minus relaxation losses at transfer
Go to 12
Determine shrinkage loss (S5.9.5.4.2) (Design Step 5.4.6.1)
Determine creep loss (S5.9.5.4.3) (Design Step 5.4.6.2)
Determine losses due to relaxation after transfer (S5.9.5.4.4c) (Design Step 5.4.6.3)
Determine total time-dependent losses after transfer by adding creep, shrinkage and relaxation losses (Design Step 5.4.6.7)
Determine stress in strands immediately after transfer as the stress prior to transfer minus instantaneous losses (Design Step 5.4.4)
Determine final stress in strands as stress immediately prior to transfer minus sum of instantaneous loss and time-dependent losses after transfer (Design Step 5.4.8).