Chapter 6-Loss of Prestress (1).pdf

Chapter 6-Loss of Prestress (1).pdf - Example Pretensioned...

Info icon This preview shows pages 1–18. Sign up to view the full content.

View Full Document Right Arrow Icon
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 2
Image of page 3

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 4
Image of page 5

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 6
Image of page 7

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 8
Image of page 9

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 10
Image of page 11

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 12
Image of page 13

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 14
Image of page 15

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Example: Pretensioned Beam Ac 684  in^2 Ic 233892  in^4 cb 25  ct 25  in Span L 75  ft f'c 6000  psi f'ci 4500  psi Beam width b 2.5  ft fpu 270000  psi (20) 1/2 in diam 7-wire strands Ap 20 0.153 3.060  in^2 Time of transfer (after stressing) tr 18  hrs fpy 0.85 fpu 229500.000  Jacking stress fpj min 0.94 fpy 0.8 fpu ( ) 215730.000  psi Harped strands emax 19  in emin 0  in Time of superimposed dead tsd 30  days after transfer Normal weight concrete, ctype=1 Lightweight concrete, ctype=2 Enter type of concrete for beam: ctype 1  Stress relieved strands, stype=1 Low relaxation strands, stype=2 Enter type of strand: stype 1  Critical Location Along Span x 0.5 L 37.500  ft Relative Humidity, % RH 75  Volume/Surface ratio VS 3.0  Solution: St Ic ct  St 9355.680 in^3 Sb Ic cb  Sb 9355.680 in^3 Ep 27000000  psi wc 115 ctype 2 = if 150 otherwise  wc 150.000 Ec 33 wc 1.5 f'c  Ec 4695982.325 psi Eci 33 wc 1.5 f'ci  Eci 4066839.989 psi wd Ac wc 144  wd 712.500 lb/ft wsd 360  lb/ft r Ic Ac  r 18.492 in Md 12 wd x 2 L x ( )  Md 6011718.75 in-lb Msd 12 wsd x 2 L x ( )  Msd 3037500.00 in-lb eccentricity e ξ ( ) emax emin 0.5 L ξ emin  ( measured from left support) T.Panayotidi .... 11/14/2016 C:\TTP\Cooper Union\CE427\ 1/3
Image of page 16