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    Structural Cracks in Beam

    Uploaded by

    swapnil gandhi
    The document discusses different types of cracks that may occur in structural beams and members: 1) Shear and flexural cracks indicate overstressing and will require retrofitting or load reduction. Shear cracks can cause brittle failure while flexural cracks are more ductile. 2) Compression failure cracks from over-reinforcement require additional reinforcement and jacketing. 3) Rusting reinforcement causes horizontal cracks requiring rust removal and repair material. 4) Alkali-silica reaction cracks are difficult to repair and may require demolition and rebuilding in severe cases.

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    Structural Cracks in Beam

    Uploaded by

    swapnil gandhi
    178 views2 pages
    The document discusses different types of cracks that may occur in structural beams and members: 1) Shear and flexural cracks indicate overstressing and will require retrofitting or load reduction. Shear cracks can cause brittle failure while flexural cracks are more ductile. 2) Compression failure cracks from over-reinforcement require additional reinforcement and jacketing. 3) Rusting reinforcement causes horizontal cracks requiring rust removal and repair material. 4) Alkali-silica reaction cracks are difficult to repair and may require demolition and rebuilding in severe cases.

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    structural Cracks in Beam

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    The document discusses different types of cracks that may occur in structural beams and members: 1) Shear and flexural cracks indicate overstressing and will require retrofitting or load reduction. Shear cracks can cause brittle failure while flexural cracks are more ductile. 2) Compression failure cracks from over-reinforcement require additional reinforcement and jacketing. 3) Rusting reinforcement causes horizontal cracks requiring rust removal and repair material. 4) Alkali-silica reaction cracks are difficult to repair and may require demolition and rebuilding in severe cases.

    Copyright:

    © All Rights Reserved
    Download as DOCX, PDF, TXT or read online from Scribd
    Download as docx, pdf, or txt
    178 views2 pages

    Structural Cracks in Beam

    Uploaded by

    swapnil gandhi
    The document discusses different types of cracks that may occur in structural beams and members: 1) Shear and flexural cracks indicate overstressing and will require retrofitting or load reduction. Shear cracks can cause brittle failure while flexural cracks are more ductile. 2) Compression failure cracks from over-reinforcement require additional reinforcement and jacketing. 3) Rusting reinforcement causes horizontal cracks requiring rust removal and repair material. 4) Alkali-silica reaction cracks are difficult to repair and may require demolition and rebuilding in severe cases.

    Copyright:

    © All Rights Reserved
    Download as DOCX, PDF, TXT or read online from Scribd
    Download as docx, pdf, or txt
    of 2

    Structural Cracks

    A) Shear & Flexural Cracks If cracks continue to grow in length and width then it is
    sign for trouble. It means the member is over stressed. The location of cracks will
    indicate what the failure mode of structural member is. In beams, for example, there
    can be mainly two types of cracks i.e. shear cracks, or flexural cracks as shown in the
    figure below.

    If these types of cracks appear in a beam then it will need retrofitting in the form of jacketing,
    or load on the beam may have to be reduced to reduce the stress within allowable limits.
    Shear failure of beam can be brittle and without any warning, while if the beam is correctly
    designed then flexural failure should be ductile.

    B)Beam may exhibit compression failure cracks which are due to incorrect design of
    beam. If beam is over reinforced, then this type of failure will occur. Cracks will appear in
    the compression zone of beam accompanied by crushing of concrete.

    Repair of such cracks may be done by providing additional compression reinforcement such
    that balanced design is achieved, and jacketing of beam.

    c)There can also be another type of cracking in structure which is caused by rusting of
    reinforcement. These are horizontal in direction and can be on the sides or bottom/top of the
    Beam or underside of Slab. Their depth will be up to the concrete cover. If this is the case
    then concrete cover needs to be removed and rust must be removed from all around the
    reinforcement, then member should be repaired by applying rust inhibitor and polymer or
    cement based repair material or epoxy coating.
    D)Another type of cracking can be due to Alkali-Silica Reaction (ASR). This happens
    when aggregates contain some minerals which react with alkalies present in concrete.
    Aggregates should be tested for ASR, or low alkali cement should be used if use of reactive
    aggregates is unavoidable. These take the form of alligator cracks with appearance of white
    bi-product of reaction in the cracks as shown below:

    These types of cracks are most difficult to deal with. The alkali-silica reaction will continue
    as long as there is alkali and reactive silica present in cement, and as long as they are in
    contact with each other. Once any of these conditions cease to exist the reaction will stop. It
    might be the case that although initially cracks appearing in the structure are very few but
    potential for ASR to continue is large, which will mean that cracking will continue and
    eventually become large. Hence, depending upon the extent of damage, and potential for
    ASR to continue, repair work can be carried out by removing the damaged concrete and
    jacketing the member. In worst case, structural member may have to be demolished and re-
    built.

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