• Home
  • Blog
  • Courses
  • Tools
  • Jobs
  • Forums
Have any question?
(00) 201277767728
[email protected]
RegisterLogin

Login with your site account

Lost your password?

Not a member yet? Register now

Register a new account

Are you a member? Login now

Planning Engineer Est.
  • Home
  • Blog
  • Courses
  • Tools
  • Jobs
  • Forums
      • Cart

        0

    Management Template

    • Home
    • Blog
    • Management Template
    • CONSTRUCTION JOINTS IN IN-SITU CONCRETE METHOD STATEMENT

    CONSTRUCTION JOINTS IN IN-SITU CONCRETE METHOD STATEMENT

    • Posted by Hany Ismail, MSC, PMP
    • Categories Management Template
    • Date February 18, 2014
    • Comments 0 comment

    CONSTRUCTION JOINTS IN IN-SITU CONCRETE METHOD STATEMENT

    1.    SCOPE

     The scope of this procedure outlines methods to be used for constructing effective and durable construction joints in accordance with the contract specifications.

     2.    PROCEDURE

    .1    In some cases CLIENT shall have to prepare shop drawings proposing location and type of construction joints and obtain approval from the Consultant’s representative before proceeding with the work.

    .2    Horizontal Surfaces:

         Laitance on the surface must be removed from the concrete in order to ensure that a good bond will be achieved when fresh concrete will be placed against it. Following methods may be used for removing laitance from the top of walls and columns unless specified otherwise in the contract:

     i)    Washing and Brushing:

     The easiest way is to brush off the laitance while the concrete is still fresh but has stiffened slightly. Brushing shall be commenced between one to two hours after placing of concrete. Site operatives shall have brushes with soft and hard bristles so that it can be used depending upon stiffness of concrete. Care shall be taken that the brushing shall not be harsh which will dislodge the coarse aggregates. In case laitance has hardened but is still green, a wire brush should be used.

     ii)    Air and Water Jet:

     Laitance can be removed by directing a jet of air and water onto it. This method can be used up to six hours after placing or possible longer but the site operative must make his own judgement while adopting this method. This operation must not start too soon because it might dislodge coarse aggregate particles.

     iii)    Mechanical Scabbling:

     If laitance is too hard to be removed by wire brushing, mechanical scabbling can be tried using small percussion power tools. This method can be applied after 3 days when concrete has hardened sufficiently. Care shall be taken not to weaken the coarse aggregates.

    iv)    Abrasive Blasting:

     Wet or dry abrasive blasting can be used to expose the aggregate but special safety precautions shall be taken while using sand.

    .3    The most appropriate time for treating the joints is a matter of judgement, because it depends on the rate of setting and hardening (which is itself dependent on the temperature of the concrete).

    .4    Where there is likely to be even a short delay before placing the next concrete pour, protruding reinforcement should be protected. Before the next pour is placed, rust, loose mortar or other contamination should be removed from the bars.

    .5    Vertical Surfaces:

    i)    Stop Ends/Expanded Metal Mesh:

    Vertical joints in walls, beams and slabs are usually formed at a stop end in the formwork. Stop ends shall be located where the reinforcement is least dense. Holes for reinforcement in stop-ends are a potential weakness because grout loss can occur. In lightly reinforced sections and where starter bars are acceptable, this problem is frequently avoided by bending bars so that they run along the inner face of the stop-end. When the stop-end is removed, the bars are cut out and straightened. However, the cutting out and straightening can damage the concrete and cause local loss of bond with the bar, especially if this is carried out within 48 hours of placing the concrete.

     Proprietary stop-ends have been developed which overcome this problem by encasing the bent bars in expanded plastic foam. The foam can easily be removed and the bars strengthened by means of a steel tube. Take particular care not to use impact to straighten bent steel at stop-ends as this can cause brittle fracture.

     Permanent forms of expanded metal are increasingly employed, particularly in deep slabs. The concrete surface produced by such system is very irregular and does not normally require any surface preparation. Where a very high workability mix is being used (slump greater than 200mm) with expanded metal formwork, care should be taken to avoid over – vibration at the joint as this may cause grout loss.

     ii)    Formwork:

     Formwork for subsequent concrete pours must be accurately aligned and well fixed so that there is no grout leak which results into discoloration and honey combing. Strips of foam rubber or polyurethane unless specified otherwise can be fixed around the edge of the hardened prepared joint.

     .6    The methods explained previously i.e. washing and brushing, mechanical scabbling and abrasive blasting can also be used in case of vertical joints. However special care shall be taken not to damage the leading edges (leave a margin).

    .7    Watertight Construction:

    i)    In watertight construction unless specified otherwise, flexible waterbars of specified details can be used. Care shall be taken while concreting so that all waterbars are securely tied to avoid its folding during concreting.

     .8    Cold Joints:

     i)    Cold joints normally occur during the concreting operation when a delay in placing adjacent concrete has occurred and earlier concrete placed has stiffened.

     ii)    A simple test can be used to determine whether concreting can proceed. Embed the poker vibrator into the existing concrete to examine the condition of concrete. Where the action of the poker has left a distinct hole, concreting operations should not continue. In this case the joint face can be prepared by one of the methods described above for horizontal construction joints.

     .9    Placing the Fresh Concrete:

     i)    Particular care as explained below shall be taken while placing and compacting new concrete on or against the old:

    ii)    Any dirt or dust from the surface of the hardened concrete shall be removed preferably with a compressed air hose. As a safety precaution site operatives must wear safety goggles. This cleaning shall be done before new formwork is fixed because not only access be easier than but also dirt might otherwise stick to the new formwork.

    iii)    While fixing a new formwork extra dirt is created which can be cleaned after removing a stop end – which will make it easy to be swept or blown away.

    .10    Joint Sealing:

     i)    Where the structural component containing the joint is to be exposed to the external environment, the joint has to be sealed to prevent ingress of water. For type and method of application refer to the contract specifications and/or manufacturer’s instructions.

      3.    DOCUMENTATION

     Following documentation and forms may be maintained as a minimum pending on Project Quality Plan requirements and contract specification.

     i)    Contract and/or approved workshop drawings.

    i)    Manufacturer’s test certificates (in case of sealants and

    waterbars).

    iii)    Request for Consultant’s consent/approval.

     The above referenced documentation where appropriate will be retained in the HEE archive for the prescribed period of time.

    Download CONSTRUCTION JOINTS IN IN-SITU CONCRETE METHOD STATEMENT in word format: CONSTRUCTION JOINTS IN IN-SITU CONCRETE

    Tag:abrasive blasting, concrete method, CONSTRUCTION JOINTS, expanded metal, IN-SITU CONCRETE, mechanical scabbling, method statement, situ concrete

    • Share:
    Hany Ismail, MSC, PMP
    Hany Ismail, MSC, PMP

    Hany Ismael is the founder and CEO of Planning Engineer Est. in Egypt. He has started his career back in 2003 as a site engineer, technical office engineer, planning engineer, planning manager, and finally planning department manager where he has been involved in several mega construction projects in Egypt and Saudi Arabia. In 2016, he established his own company in Egypt “Planning Engineer Est.” Hany gained his MSc degree in project management from Liverpool University-UK 2013-2016, PMP certified from PMI-USA 2010, and BSc Civil Engineer Tanta University-Egypt 2003. Hany provided more than 3,500 hours of planning and project management training on his website planningengineer.net, YouTube channel, and offline courses since 2011. He enjoys teaching project management in simple and practical way, and he developed several planning tools, techniques and courses.

    Previous post

    Concrete Pavings Method Statement
    February 18, 2014

    Next post

    Block work Method Statement
    February 22, 2014

    You may also like

    2022-06-19_11-56-47
    Sample Weekly and Monthly Reports
    20 June, 2022
    Power Bi
    Power BI is the next level of data analytics and visualization
    20 February, 2019
    MEP-Engineer-Job-Description
    MEP Engineer Job Description template
    24 November, 2018

    Leave A Reply Cancel reply

    You must be logged in to post a comment.

    Cart

    0

    Planning Courses

    Cost Control for Construction Projects

    Cost Control for Construction Projects

    $299.00
    Power Bi Monitoring and Controlling with P6

    Power Bi Monitoring and Controlling with P6

    $299.00
    Advanced Planning 3 Courses Package

    Advanced Planning 3 Courses Package

    $499.00
    Data Management and Reporting

    Data Management and Reporting

    $199.00
    Primavera Online Basic Course -Arabic

    Primavera Online Basic Course -Arabic

    $99.00
    Professional Planning Engineer (PPE)

    Professional Planning Engineer (PPE)

    $335.00
    Claims Management and (EOT)

    Claims Management and (EOT)

    $175.00
    Primavera Online Basic Course -English

    Primavera Online Basic Course -English

    $99.00

    Follow Us:

    About Us | Contact Us | Terms of Service | Privacy Policy | Refund Policy

    Copyright ©2012- 2018 planningengineer.net | All materials, unless otherwise noted, were developed originally for Planning Engineer Website. In the event that there is still a problem or error with copyrighted material, the break of the copyright is unintentional and noncommercial and the material will be removed immediately upon presented proof.

    • Planning Courses
    • Planning Jobs
    • Planning Blog
    Posting....