Tools

Shear Strength of Reinforced Concrete Beam

Procedure


  1. Place the beam on the loading frame.
  2. Measure the depth (D), width (b) and length (L) of the beam.
  3. Measure the distance between the loading points and supports.
  4. Apply the load. Apply the load slowly and steadily.
  5. Increase the load till the failure occurs and note the failure load.

Observations and Calculations

  1. Grade of concrete (fck) =
  2. Grade of steel (fy) =
  3. Density of concrete (ρ) =
  4. Area of tension steel (Ast) =
  5. Length of beam between aupports (L’) =
  6. Depth of beam (D) =
  7. Effective depth of beam (D) =
  8. Width of beam (b) =
  9. Effective depth of beam (d) =
  10. Location of crack from support (La) =
  11. Location of crack from support (Lc) =
  12. Failure load (P) =

Predicted value of load at failure, Vpred (refer to Table 19 of IS:456-2000)

  • τv =
  • d =
  • b =
  • Vpred =

    • Observed value of load at failure, Vobs

  • P =
  • D =
  • b =
  • Lb =
  • Vobs = P/2 + ρLbbD

    • Factor of safety (FOS)

    The FOS is defined as the ratio of Vobs and Vpred.
  • FOS = Vobs / Vpred =

    • Precautions

    1. Before casting, ensure the beam section is without shear reinforcements and under reinforced.
    2. Mix design calculations before preparing concrete for casting should be accurate.
    3. Ensure compaction of the beam is done properly, to obtain accurate test results.
    4. Testing must be done after a minimum of 28 days.
    5. Before testing the beam, check if the load cell and hydraulic jet are functioning properly.
    6. Wear safety helmet and shoes while performing the experiment.