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  1. rapt

    Do you think it is right to design it as a 150cmx150cm column and rod element?

    Never used Etabs but I would assume a ROD element is a tension element!
  2. rapt

    Under-reinforced beam

    I disagree with stripping the formwork if the strength under the construction load is ok. It is far better to add strengthening before any deflection has occurred.
  3. rapt

    Partially Developed Reinforcement

    If you limit the bar size, you could ensure the bar can develop yield at the critical section for bending near the inside face of the column. So the maximum bar size would be dependent on the support length. In ASS3600, you would get 50% development from the cog, plus the length to the critical...
  4. rapt

    Partially Developed Reinforcement

    There is a phi factor built into in the bond calculation for reduced capacity of the reinforcement. In Eurocode, which actually provides the basic calculation , converting material factors to equivalent phi, that comes to about 1.15 / 1.5 = .75. This is built into the Australian code development...
  5. rapt

    When does a cantilever concrete beam become classified as a deep beam?

    Unless you have a heavy point load on the end of the cantilever, why are you worried about S/T modelling anyway? Whatever reinforcement you need at the end column for the internal span would be adequate for the short cantilever.
  6. rapt

    Would use of a corner bar in standard hook shorten the development length?

    The main benefit of a corner bar is to reduce the compression stress concrete in the curve of the main bar, thus allowing tighter bend radius. This is useful for stirrups and other applications where bend radii are a problem in detailing such as corbels. Eurocode and the FIB Model Code have...
  7. rapt

    New corbel on existing concrete structure

    You have simply created a new tension zone at the back of the anchors. Is there other horizontal reinforcement to transfer that tension force further into the kerb/deck?
  8. rapt

    Prestress Losses for PT Column Rods

    Actually steel relaxation would probably be the worst loss for prestress bar/rods. It is normally not Low Relaxation like strand!
  9. rapt

    Punching Shear Critical Perimeter EN 1992-1 version 2015 VS 2021

    The old method was based on Zustti's logic and the perimeter was set at the larger distance to match the method to test results. The new code uses The Critical Shear Crack Theory developed by Muttoni and has gone back to using .5d for the perimeter, along with limitations on the length of the...
  10. rapt

    Specifying Steel Fibers in Slab

    It also depends on the type of steel fiber. Not all fibers are equal.
  11. rapt

    AS3600 Boundary elements in moderately ductile shear walls

    14.6.2.1 specifically says when boundary elements are required in each storey.
  12. rapt

    AS3600 Boundary elements in moderately ductile shear walls

    It is meant to be performed using the ductility factor and structural performance factor assumed by the designer. Where 1 and 1 are required, the code specifically says so.
  13. rapt

    Cracks on pier cap

    I would say restraint complicated by lack of development of the bottom reinforcement into the connection. There appears to be some vertical separation across the joint in the second photo!
  14. rapt

    Repairing Post-tension slab

    The last photos and gap in the damaged area appears to show a bad quality concrete wearing slab above and rotten timbers between that and the precast slab panels. Is the part where the concrete has broken off part of a plank or an edge insitu infill strip? And the damage appears to be...
  15. rapt

    Repairing Post-tension slab

    Optical illusion! More photos help!
  16. rapt

    Repairing Post-tension slab

    How thick is the delaminated piece. It looks very thin. And the slab also looks very thin. Minimum for post tensioned would normally be 5 - 6" thick. Are you sure it is post-tensioned, or is it a thin pretensioned precast decking panel with a thin topping/wearing surface? Holes could be old...
  17. rapt

    Hairline Cracked Concrete Upheaval after 4-6 days.

    I was thinking plastic shrinkage cracking from the pattern, but have never see the upheaval like that. Was an extra thin layer added during the finishing to get the correct surface level?
  18. rapt

    Temporary Top Strands in Prestressed I-Girders

    If they are left in place, they will affect the calculations and should be included for both serviceability and ultimate strength.
  19. rapt

    Temporary Top Strands in Prestressed I-Girders

    In what way are they "temporary"? Are they somehow removed after a certain time?
  20. rapt

    Shear reinforcement in two way slab

    He is talking about 2 orthogonal shear planes because that is how people treat detailing of slabs. They convert the results to 2 orthogonal directions because that is how you place the reinforcement. For flexure, you could just as easily calculate the reinforcement required based on then...
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