Load-bearing vertical structural component for one or more stories. Made with or without corbels.
- Minimum prestress = 225 psi.
- Strand assumed 1/2 in. in diameter; fpu=270 ksi.
- Curves shown for partial development of strand near member end, where fps≈ fse.
- Horizontal portion of curve is the maximum for tied columns: 0.80ΦPo.
- Varies linearly from 0.9 for tension-controlled section to 0.65 for compression-controlled sections in accordance with ACI 318-05, section 9.3.2.
- Use of Curves
- Enter at left with applied factors axial load, Pu.
- Enter at bottom with applied magnified factored moment, ΦMu.
- Intersection point must be to the left of the curve that indicates required concrete strength.
12 x 12
14 x 14
16 x 16
18 x 18
20 x 20
24 x 24