CONCRETE

  1. All workmanship and materials shall be in accordance with relevant codes.
  2. Reinforcement grade symbols designation and yield stress:
    • R/SL : Ductility Class L reinforcing mesh yield strength= 500 MPa
    • N : Ductility Class N deformed bars yield strength = 500 MPa
    • L : Ductility Class L deformed bars yield strength = 500 MPa
    • R : Plain round bars yield strength = 230 MPa

    The number immediately following the bar symbols L, N and R represents the nominal bar diameter in mm. The number following the RL or SL symbol is the fabric size coding.

  3. Fabric splices shall be staggered to ensure no more than three fabric thicknesses occur at any one point. Concrete cover shall be maintained where fabric splices occur.
  4. Splices in reinforcement shall be staggered by alternating bars or by other means and shall only be made in the positions shown unless approved otherwise by the Engineer.
  5. Where the lap length is not shown it shall be sufficient to develop the full strength of the reinforcement and shall be 40 bar diameters uno.
  6. Slab reinforcement shall be firmly supported on plastic or concrete (of same grade as matrix) chairs. SL72 mesh may require additional support bars. Each beam ligature shall be secured to a bar in each corner of the ligature.
  7. Sizes of concrete elements do not include thickness of applied finishes.
  8. Construction joints where not shown shall be to the approval of the Engineer. All construction joints shall be scabbled and thoroughly cleaned of loose material before placing fresh concrete.
  9. Where joints are to be saw cut, cutting shall take place within 24 hours of concrete placement.
  10. No holes or chases other than those shown on the structural drawings shall be made in concrete elements without the prior approval of the Engineer.
  11. Curing shall commence as soon as the exposed surface of the concrete has hardened, to prevent damage, but in no case later than two hours after the finishing operation has been completed. The curing method shall be in accordance with relevant standards as approved. Curing compounds shall not be used without prior approval.
  12. Concrete quality shall be as tabulated uno, and shall be verified by tests :
    Element Exposure Class’n Class/
    Grade
    Slump
    mm
    Aggregate
    Size mm
    Cement
    Type
    Footing Piers A2 N20 80 20 GP
    Slabs on ground A1 N32 80 20 GP
  13. Clear concrete cover uno.
    Element Cover (mm)
    Floor Slabs 20mm Top, 30mm Bottom (with Damp Proof Membrane)
    Footing Beams 45mm Top
    40mm Sides & Bottom (without Damp Proof Membrane)
    30mm Sides & Bottom (with Damp Proof Membrane)
    Footing Piers 70mm for surfaces in contact with ground

 

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