Discussion: View Thread

  • 1.  Structural Engineering Mentor

    Posted 10-04-2022 12:57 PM

    I need a structural engineer mentor to discuss the cracks development in the slab which seems to be over reinforced beams that are not loaded fully. I think, beams with 20mm dia rebars has no problem, beams with 16mm dia rebars has problem about slab. 



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    Alex Thomas R.Eng, C.Eng, M.ASCE
    Engineer
    Ajit Associates+Acd
    CochinAlexThomasR.Eng, C.Eng, M.ASCEIndia
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  • 2.  RE: Structural Engineering Mentor

    Posted 10-05-2022 09:08 AM
    I have uploaded the photos

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    Alex Thomas R.Eng, C.Eng, M.ASCE
    Engineer
    Ajit Associates+Acd
    CochinAlexThomasR.Eng, C.Eng, M.ASCEIndia
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  • 3.  RE: Structural Engineering Mentor

    Posted 10-06-2022 10:49 AM
      |   view attached
    [10/6, 3:53 PM] Alex Thomas: Roof of ground floor is done by me with beams 5 numbers 20mm dia rebars, which shows no problem, but roof of first floor is done by an Architect with beams has rebars of 6numbers 16mm dia rebars, cracks devoloped in discontinues end portion having a small over hang .
    [10/6, 3:53 PM] Alex Thomas: The first portion is, I think action of proped cantilever beam,

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    Alex Thomas R.Eng, C.Eng, M.ASCE
    Engineer
    Ajit Associates+Acd
    CochinAlexThomasR.Eng, C.Eng, M.ASCEIndia
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  • 4.  RE: Structural Engineering Mentor

    Posted 05-08-2023 08:02 AM

    Are there any changes in the dimensions of the beam in the middle of the beam as designed by an architect? Any change in dimensions in the middle of the beam must not be allowed. Is the reinforcement continuously at the same level with sufficient cover? If these aspects are already looked into, check whether theses beams are designed for the bending moment and shear forces coming on the beam. If you show pictures of the ground floor, more clarity may come. This is my opinion based on the picures shown. 



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    Rama Raju Kunadharaju Ph.D., P.E., M.ASCE
    Former Chief Scientist
    Structural Engineering Research Centre
    Chennai TN
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  • 5.  RE: Structural Engineering Mentor

    Posted 10-09-2022 10:39 AM

    Dear Alex, thank you for sharing. Could you please send us some pictures with closer details? I can not see the crack development and a proper scale factor.

    Regards,
    AG



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    Andres Guzman D.Eng., MEng, Ing., M.ASCE
    Associate Professor
    UNIVERSIDAD DEL NORTE
    Barranquilla
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  • 6.  RE: Structural Engineering Mentor

    Posted 10-10-2022 10:58 AM
    Alex,

    The Area of steel for your design is 1570.8mmversus the 1206.3mm2 for the roof of the first floor. About 23%. It may have more to do with the concrete mix and how fast it is curing, maybe without being kept wet for the first 7 days or no curing compound applied. If the cracks are not getting wider, and no other problems like deflection have been seen, then the best course right now is to seal the cracks with a flexible sealant, like urethane based sealant and monitor it for any changes. Keeping moisture away from the rebars to inhibit corrosion is a necessity on any exposed surfaces. Good Luck.

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    William Bala P.E., S.E., M.ASCE
    Owner
    Hawkins TX
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  • 7.  RE: Structural Engineering Mentor

    Posted 10-10-2022 06:02 PM
      |   view attached
    Uploaded drawing span 460cm

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    Alex Thomas R.Eng, C.Eng, M.ASCE
    Engineer
    Ajit Associates+Acd
    CochinAlexThomasR.Eng, C.Eng, M.ASCEIndia
    ------------------------------