Prestressed Concrete Calculator
Estimate prestress losses (elastic shortening, creep, shrinkage, relaxation) and effective prestress for pretensioned concrete members.
Inputs
ACI 318: max jack 0.80×fpu=1488 MPa; at transfer 0.74×fpu=1376 MPa; low-relax strand fpu=1860 MPa
ASTM A416 Grade 270: 12.7mm strand 98.7 mm²; 15.2mm (0.6") 139.4 mm² (most common)
Results
Initial Prestressing Force
2,343,600 N
Total Prestress Losses
233.93 MPa
Effective Prestress
1,161.07 MPa
How to Use This Calculator
- Enter the beam span, cross-section dimensions, and concrete strength at transfer and 28 days.
- Input the prestressing steel area, initial prestress force, and eccentricity.
- Set the superimposed dead load and live load in kips per foot.
- Review the Prestress Losses, Net Prestress Force, and the Cracking Moment.
- Check that stresses at transfer and service remain within ACI 318 permissible limits.
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