Your SlideShare is downloading. ×
Compressive Membrane Action in Concrete Decks
Upcoming SlideShare
Loading in...5
×

Thanks for flagging this SlideShare!

Oops! An error has occurred.

×

Introducing the official SlideShare app

Stunning, full-screen experience for iPhone and Android

Text the download link to your phone

Standard text messaging rates apply

Compressive Membrane Action in Concrete Decks

1,655
views

Published on

My presentation at fib Symposium for Civil Engineering, Karlsruhe 2012.

My presentation at fib Symposium for Civil Engineering, Karlsruhe 2012.

Published in: Technology, Business

0 Comments
1 Like
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total Views
1,655
On Slideshare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
Downloads
21
Comments
0
Likes
1
Embeds 0
No embeds

Report content
Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
No notes for slide

Transcript

  • 1. Compressive Membrane Action in Concrete Decks 9th fib International PhD Symposium in Civil Engineering Karlsruhe Institute of Technology (KIT), Germany Sana Amir 24-07-2012 Prof. Dr. ir. J. C. Walraven, Dr. ir. C. van der Veen Structural Engineering / Concrete Structures van de presentatie Titel 1
  • 2. Contents1: Introduction: Compressive Membrane Action2: CMA in reinforced concrete decks - Flexural load carrying capacity - Punching Shear capacity3: Application of CMA theories to experimental data4. CMA in transversely prestressed concrete decks : InvestigatingPunching Shear capacity5. Future Tests6. Conclusions Titel van de presentatie 2
  • 3. IntroductionCompressive Membrane Action CMA is a phenomenon that occurs in slabs whose edges are restrained against lateral movement by stiff boundary elements. This restraint induces compressive membrane forces in the plane of the slab (Park and Gamble, 1980). Titel van de presentatie 3
  • 4. IntroductionCompressive Membrane Action• Bridges are traditionally designed to carry the wheel load entirely inflexure. ASSUMPTION: Adequate shear capacity.• A bridge deck slab designed for bending tends to fail in the punchingshear mode at a load much higher than that based on flexure. ?• Considerable research is done on reinforced decks. Prestressed decksneed to be investigated. PhD Research Titel van de presentatie 4
  • 5. CMA in reinforced concrete decks Flexural Capacity by Rankin and LongMarc  ArchingCap acityMb  BendingCap acity Pflx  k (Marc  Mb) ka = 8/L and kb = 4/L Titel van de presentatie 5
  • 6. Punching Shear CapacityKirkpatrick, Rankin, Long, Taylor’s ApproachUK HIGHWAY AGENCY STANDARD BD 81/02 kf c/ h 2 Qe  320  0.75d 2 Pp  1.52(  d )d f c (100Qe )0.25 / Titel van de presentatie 6
  • 7. Punching Shear CapacityMikael Hallgren Model • Modified form of Kinnunen – Nylander Model. Limitation: Analysis of symmetric punching of reinforced slabs without shear reinforcement – Open to further development. Titel van de presentatie 7
  • 8. Punching Shear CapacityModified Hallgren Model where Fb = η Fb(max) and Mb = η Mb(max) Titel van de presentatie 8
  • 9. Application to Experimental Data Tests by Taylor et al (2001) Test Panel Pt PBS PBD81 Ptaylor Pmh Pt / PBD81 Pt / Ptaylor Pt / Pmh [kN] [kN] [kN] [kN] [kN] D1 185 49.4 341.1 191.8 219.8 0.54 0.96 0.84 D2 200 49.3 317.6 181.3 206.8 0.63 1.10 0.97 D5 150 38 268 151.1 164.5 0.56 0.99 0.91 D6 182 38.1 276 173.3 184.12 0.66 1.05 0.99 D7 135 38.1 280.9 92.5 155.29 0.48 1.46 0.87 D8 157 38.7 274 148.9 167.45 0.57 1.05 0.94 Average 0.57 1.10 0.92 St. deviation 0.06 0.18 0.057 Capacity predictions for reinforced concrete decks Titel van de presentatie 9
  • 10. Application to Experimental Data Tests by Kirkpatrick et al (1984) Capacity predictions for reinforced concrete decks Titel van de presentatie 10
  • 11. Application to Experimental Data Tests by Taylor et al (2007) Test Panel Deflection Pt PBD81 Pmh PBS PBD81/PBS Pmh/PBS Pt/Pmh [mm] [kN] [kN] [kN] [kN] A1 2.5 333 570.1 401 128.3 4.44 6.75 0.83 A2 1.5 428 600.8 426.4 178.3 3.37 5.70 1.00 B1 2.15 344 563.6 381 66.5 8.48 11.07 0.90 B2 1.15 428 610.4 445.2 92.3 6.61 9.60 0.96 C1 2.6 333 588 406 66.6 8.83 11.58 0.82 C2 1.2 428 588 427.5 92.2 6.38 9.24 1.00 D1 1.85 368 553.5 365 127.9 4.33 5.51 1.01 D2 1.75 428 568.3 412 177.3 3.21 5.35 1.04 E1 1.95 392 632.8 484 202.1 3.13 3.89 0.81 E2 1.6 428 648.7 484.7 280 2.32 3.36 0.88 F1 1.9 371 566.5 415 199.5 2.84 3.56 0.89 F2 0.75 428 601.2 464.2 275.2 2.18 3.19 0.92 Average 0.92 St. deviation 0.08 Capacity predictions for reinforced concrete decks Titel van de presentatie 11
  • 12. Prestressed Concrete Decks• Provisional of additional in-plane forces due to prestressing• Improved punching shear capacity• Improved serviceability Titel van de presentatie 12
  • 13. Analysis Methods Engineering Method Modified Hallgren Model  ps f pe e   s  fy Charts from OHBDC or NZ code may be used to estimate the ultimate capacity. where Fb = η Fb(max) and Mb = η Mb(max) Method of superposition Punching Load Boundary Lateral Prestressing Restraint Titel van de presentatie 13
  • 14. Test Panel Ap TPL Pt Pmh PNZ Pt/Pmh Pt/PNZ [mm2] [MPa] [kN] [kN] [kN] SW-1A 0.0869 1.84 53.1 59.77 67.39 0.89 0.79 SE-1B 0.0869 1.84 53.04 59.77 67.39 0.89 0.79 CW-2B 0.105 2.15 54.82 64.16 70.45 0.85 0.78 CE-2B 0.105 2.15 57.26 64.16 70.45 0.89 0.81 NW-2A 0.1198 2.5 63.85 67.57 71.68 0.94 0.89 NW-2B 0.1198 2.5 48.7 67.57 71.68 0.72 0.68 CE-1B 0.14 2.91 74.43 72.08 74.74 1.03 1.00 CW-1A 0.14 2.91 65.82 72.08 74.74 0.91 0.88 SE-2B 0.1549 3.32 66.31 75.42 76.58 0.88 0.87 SW-2A 0.1549 3.32 72.97 75.42 76.58 0.97 0.95 NE-1B 0.176 3.88 80.54 80.15 79.65 1.00 1.01 NW-1A 0.176 3.88 77.52 80.15 79.65 0.97 0.97 CE-1A 0.19 4.37 94.12 83.42 80.87 1.13 1.16 NE-2A 0.19 4.37 92.28 83.42 80.87 1.11 1.14 NW-3B 0.19 4.37 80.11 83.42 80.87 0.96 0.99 CW-4B 0.19 4.37 82.66 83.42 80.87 0.99 1.02 SE-5B 0.19 4.37 87.3 83,42 80.87 1.05 1.08 SW-6A 0.19 4.37 92.23 83.42 80.87 1.11 1.14 Average 0.96 0.94 St. deviation 0.10 0.14 Tests in Queen’s University, Kingston, Canada Titel van de presentatie 14
  • 15. (TPL ~ Punching Load) 100 90 Pt Punching Load (kN) Pmh 80 PNZ 70 Linear (Pt) 60 50 40 0 1 2 3 4 5 TPL (MPa) Savides (1989), He (1992) Tests in Queen’s University, Kingston, Canada• Prestressing postpones the commencement of lateral movements, delays cracking.•Lesser the lateral movement possible, higher is the level of CMA leading to higherpunching loads. Titel van de presentatie 15
  • 16. FUTURE TESTS • Variable TPL • Joint skewness and roughness • Variable position/locations of the load Transverse Prestress Level 1.25 MPa 2.5 MPa 6400 Titel van de presentatie 16
  • 17. Titel van de presentatie 17
  • 18. Titel van de presentatie 18
  • 19. Conclusions & Future Study•The UK Highway Agency BD81/02 gives good results for rigidly restraint deck slabs.However, when the restraint is low, the results are unsafe. Also, this method does notallow for the effect of varying reinforcement ratio.•Taylor’s approach incorporates both flexural punching and shear punching failures.•The New Zealand code gives better estimation when the TPL is high.•Modified Hallgren model gives good results both for reinforced and transverselyprestressed deck slabs, therefore it will be used for future tests as well.• Deck slabs exhibit high punching strength in the presence of CMA resulting from lateralrestraint and transverse prestressing.•Future Study: Working on a 3D Nonlinear FEM Analysis. Titel van de presentatie 19
  • 20. Thank you Titel van de presentatie 20