From: Subject: ACES PSC Module - Prestress Losses Date: Sun, 12 Jul 2009 22:03:29 +0930 MIME-Version: 1.0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Content-Location: file://C:\ACES6\Tempdata\PSC Module-Page-Data.htm X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3028 ACES PSC Module - Prestress Losses

ACES PSC Design Module V1.000:   Run=20 date:  23-JUN-09
-------------------------------------------= ------------------------------------------------------
Heading: &= nbsp; Test=20 module
Job Name: AS5100 SUPER-T CLOSED TOP : = SUPERT-CLSD3
Designer:=20  GS

Comments: No comments

Units: =    mm,=20 microstrain, kN, kN.m,=20 MPa
------------------------------------------------------------------= -------------------------------

DESIGN=20 CODE: AS5100.5-2004

PRESTRESS LOSSES

  Initial jacking force (Pj)

=3D

6750

    kN
  Jacking force factor (Jf)

=3D

0.750

   
           
  Loss due to Steam Relaxation        
           
  The steam relaxation factor (k5) is the = larger of 0.0=20 or:
       The maximum of: k5a = =3D 1 +=20 (Jf-0.7)*0.5/0.1

=3D

1.250

  (AS5100.5-2004 (Fig 6.3.4))
       and: k5b =3D = (Jf-0.4)/0.3

=3D

1.167

   
           
  Steam relaxation factor (k5)

=3D

1.250

   
  Loss due to relaxation (Lsrl =3D = 0.1*k5/1.5)

=3D

0.083

 
           
  Loss in PS due to relaxation (Prl =3D - = Lsrl*Pj)

=3D

-562.5

  kN
  Loss as a proportion of Pj (Lsr =3D - = Prl*100/Pj)

=3D

8.3

  % 
  PS force remaining (Pjr =3D Pj + Prl)

=3D

6187.5

  kN
           
  Elastic Deformation Loss        
           
  Area of PS steel (Ap =3D = Nbbars*Pi*Ds^2/4)

=3D

5040.0

  mm^2
           
  Mean Young's Modulus of girder concrete = (Egmt)

=3D

21000.0

  MPa 
  Young's Modulus of stressing steel (Ep) =  

=3D

200000.0

  MPa
  Area of girder (Ag)

=3D

585200.0

  mm^2 
  Moment of inertia of girder (Ig)

=3D

   1.1710E+11

  mm^4
  Dist between CG girder and CG of strands = (e)

=3D

111.7

  mm 
  Moment due to girder selfweight (Msw)

=3D

600.0

  kN.m 
           
  Stress at CG of strand group:      
           
  fcgs =3D - Pjr*1000*(1/Ag + e^2/Ig) + = Msw*10^6*e/Ig=20  

=3D

-10.66

  MPa
           
  Elastic deformation loss:
  Pelastic =3D - fcgs*Ep*Ap/(Egm*1000)

=3D

-511.7

  kN.m 
  Loss as a proportion of Pj (Ledl =3D - = Pelastic*100/Pj)

=3D

7.6

  %
           
  PS force at transfer (Pt =3D Pjr + Pelastic)

=3D

5675.8

  kN
  PS at transfer as a proportn of Pj (Ltr =3D = Pt*100/Pj)

=3D

84.1

  %
           
  Shrinkage Loss      
           
  Shrinkage strain (us) [Figure 6.1.7]

=3D

300.0

  microstrain
  Modular ratio (n =3D Es/Eg)

=3D

1.143

 
  Area of longitudinal reinforcement = (Arft)

=3D

6597

  mm^2
  Area of composite girder (Ac =3D n*As + = Ag)

=3D

   1133772

  mm^2
         
  Loss in PS due to shrinkage:
  Pshr =3D - us*Ep*Ap*10^-9/(1 + = 15*Arl/Ac)

=3D

-278.1

  kN (AS5100.5-2004 Clause 6.4.3.2)
  Loss as a proportion of Pj: (Lshr =3D -=20 Pshr*100/Pj)

=3D

4.1

  %
  PS force remaining after shrinkage:=20 (Prs=3DPt+Pshr)

=3D

5397.7

  kN
           
  Creep Loss due to Prestress & = Self-Weight        
           
  Moment due to girder self-weight (Msw)

=3D

600.0

  kN.m
  Area of composite girder (Ac)

=3D

1.1340E+06

  mm^2
  Exposed girder perimeter (Gp)

=3D

3214

  mm
  Void perimeter (Vp)

=3D

2500

  mm
  Young's Modulus of girder at 28 days (Eg)

=3D

35000

  MPa
  Mean girder concrete strength at transfer = (f'cmt)

=3D

50.0

  MPa
  28 day girder concrete strength (f'cg)

=3D

50.0

  MPa
           
  Theoretical thickness (th =3D = 2*Ac/(Gp +=20 0.5*Vp))

=3D

477.24

  (AS5100.5-2004 Clause 6.1.7)
  Ratio of concrete strengths (Fratio =3D=20 f'cmt/f'cg)

=3D

1.00

   
           
  Basic creep factor (=D8ccb)

=3D

2.00

  (AS5100.5-2004 Table 6.1.8a)
  Creep coefficient (k2)

=3D

0.76

  (AS5100.5-2004 Figure 6.1.8a)
  Creep coefficient (k3)

=3D

1.25

  (AS5100.5-2004 Figure 6.1.8b)
  Design creep factor (=D8cc =3D = =D8ccb*k2*k3)

=3D

1.90

  (AS5100.5-2004 Clause 6.1.8.2)
           
  Creep stress at CG of strand group:        
  fcscgs =3D -Pt*1000(1/Ag + e^2/Ig) + = Msw*10^6*e/Ig=20  

=3D

-9.73

  MPa
           
  Creep strain at CG of strand group:        
  ucc1 =3D fcscgs* =D8cc/(Eg*10^6)

=3D

-528.3

  microstrain
           
  Creep Loss due to Deck & Superimposed=20 Loads  
           
  Deal load moment of concrete slab = (Mslab)

=3D

500.0

  kN.m
  Moment due to superimposed loads = (Msdl)

=3D

50.0

  kN.m
  Moment of inertia of girder (Ig)

=3D

   1.1710E+11

  mm^4
  Moment of inertia of composite sectn = (Ic)

=3D

2.5570E+11

  mm^4
  Height to centroid of girder (Yb)

=3D

605.0

  mm
  Height to centroid of composite sectn = (Yc)

=3D

941.3

  mm
  Height to CG of strand group (Ycgs)

=3D

493.3

  mm
           
  Stress at CG due to concrete deck:        
  Fdeck =3D Mslab*10^6*(Yb - Ycgs)/Ig

=3D

0.48

  MPa
  Stress at CG due to superimposed = DL:
  Fsdl =3D Msdl*10^6*(Yc - Ycgs)/Ic

=3D

0.09

  MPa
           
  Youngs Modulus of insitu slab concrete = (Es)

=3D

40000

  MPa
  Ratio of concrete strengths (Fratio =3D=20 f'cmt/f'cg)

=3D

1.00

   
           
  Basic creep factor (=D8ccb)

=3D

2.00

  (AS5100.5-2004 Table 6.1.8A)
  Creep coefficient (k2s)

=3D

0.76

  (AS5100.5-2004 Figure 6.1.8A)
  Creep coefficient (k3s)

=3D

1.25

  (AS5100.5-2004 Figure 6.1.8B)
  Design creep factor (=D8cc2 =3D = =D8ccb*k2s*k3s)

=3D

1.90

  (AS5100.5-2004 Clause 6.1.8.2)
           
  Creep strain at CG of strand group:
  ucc2 =3D =D8cc2*10^6*(Fdeck+Fsdl)/Eg

=3D

30.6

  microstrain
           
  Total creep strain:
  ucc =3D ucc1 + ucc2

=3D

-497.6

  microstrain
           
  Summary of Creep Losses      
           
  Loss in PS due to creep (Pcreep =3D - = ucc*Ep*Ap/10^9)=20    =3D

-501.6

  kN
  Loss as a proportion of Pj (Lcr =3D = Pcreep*100/Pj)=20 =            =3D

7.4

  %
  Total remaining prestress force (P =3D Pt - = Pshr -=20 Pcreep)  =3D

4896.1

  kN
  Total loss of PS as a proportion of Pj (Ltt = =3D=20 P*100/Pj)    =3D

72.5

  %
   
           
  Summary of Prestress Losses        
 

Force (kN)

    %Pj    = =20

JACKING FORCE (Pj)

6750.0

100

Loss in PS due to relaxation

-562.5

8.3

Loss in PS due to elastic deformation

-511.7

7.6

     
TRANSFER FORCE (Pt)

5675.8

84.1

Loss in PS due to shrinkage

-278.1

4.1

Loss in PS due to creep

-501.6

7.4

     
FINAL PS FORCE = (P)

4896.1

72.5 =