RCC Questions (R6)

In this post, I will share some important questions which are frequently asked in competitive examinations such as SSC, UPSC and state PSCs.



  1. How diagonal tension reinforcement is provided in a beam?


    1. Longitudinal Bars
    2. Helical reinforcement
    3. Bent-up bars
    4. None of the above

    View Answer
    Answer: c

  2. Why minimum shear reinforcement is provided in a beam?


    1. To resist the bond stress at the support
    2. To resist shear at the support
    3. To arrest the longitudinal cracks on side faces due to shrinkage and temperature variation.
    4. All of the above

    View Answer
    Answer: c
    The minimum shear reinforcement is provided in a beam so that beam does not fail in shear when the shear strength of concrete gets reduced due to tension-induced into the beam through shrinkage or some restraint.

  3. The maximum value of permissible shear stress is based on ...


    1. Diagonal tension failure
    2. Diagonal compression failure
    3. Flexural compression failure
    4. Flexural tension failure

    View Answer
    Answer: b
    The maximum permissible shear stress is based on diagonal compression failure because if the total area of stirrups and bent-up bars exceed a certain limit, the section might become stronger in diagonal tension as compared to diagonal compression. Hence, a shear compression failure may occur even before the shear reinforcement has yielded and that is an undesirable situation as the nature of the failure is brittle.

  4. The first crack formed in a deep beam is ...


    1. Diagonal crack due to tension
    2. Diagonal crack due to compression
    3. Shear crack
    4. Flexural crack

    View Answer
    Answer: a

  5. What will be the maximum spacing between vertical stirrups in an RCC beam when the effective depth is 300 mm?


    1. 250 mm
    2. 300 mm
    3. 275 mm
    4. 225 mm

    View Answer
    Answer: d
    The maximum spacing is the minimum of 0.75 times the effective depth of beam and 300 mm.

  6. An RCC beam of effective depth 1 m and effective span 10 m is supported on columns of size 500 mm X 500 mm. If the beam is loaded with a UDL of 10 MN/m then what is the design shear force?


    1. 37.5 MN
    2. 50 MN
    3. 43 MN
    4. 47.5 MN

    View Answer
    Answer: a
    The critical section is 1 m from the face of the support and 1.25 m from the centre of the support.
    shear force at support is 50 MN
    Design Shear force $=50-10\times (0.25+1)=37.5$ MN

  7. Which of the following is correct for compression steel?


    1. ${L}_{d}=\frac{\phi {\sigma}_{s}}{4 {\tau}_{bd}}$
    2. ${L}_{d}=\frac{\phi {\sigma}_{s}}{5 {\tau}_{bd}}$
    3. ${L}_{d}=\frac{\phi {\sigma}_{s}}{6.4 {\tau}_{bd}}$
    4. ${L}_{d}=\frac{\phi {\sigma}_{s}}{8 {\tau}_{bd}}$

    View Answer
    Answer: b
    In the case of compresstion steel the bond stress is increased by 25%.

  8. How bond stress gets changed when HYSD bars are used?


    1. Its value increased by 25%
    2. Its value decreased by 25%
    3. Its value increased by 50%
    4. Its value decreased by 50%

    View Answer
    Answer: c

  9. The term "${M}_{1}/V$" in the expression ${L}_{d}\leq {M}_{1}/V + {L}_{0}$ is increased by ____ when the reaction is compressive.


    1. 25%
    2. 30%
    3. 45%
    4. 60%

    View Answer
    Answer: b
    As per IS 456, Cl 26.2.3.3, the term ${M}_{1}/V$ is increased by 30%.

  10. In above question, what is the value of ${L}_{0}$?


    1. The effective depth of the member
    2. 12 times the diameter of the bar
    3. Smaller of (a) and (b)
    4. Greater of (a) and (b)

    View Answer
    Answer: d
    As per IS 456, CL 26.2.3.3, it is greater of the first two options.

  11. Which of the following statements is incorrect?


    1. If the bars are larger than 36 mm in diameter, Lap splices are not generally provided.
    2. Lap length including anchorage value of hooks for the bar in flexural tension shall be ${L}_{d}$ or $12 \phi$, whichever is greater.
    3. The straight length of the lap shall not be less than $12 \phi$ or 200 mm.
    4. None of the above

    View Answer
    Answer: c
    As per IS 456, Cl 26.2.5.1 [c], it is $15 \phi$ or 200 mm.

  12. If "D" is the diameter of the bar, then what is the anchorage value of the U-hook?


    1. 12D
    2. 16D
    3. 18D
    4. 20D

    View Answer
    Answer: b
    As per IS 456, Cl 26.2.2.1 [b-2], it's "16D"

  13. What is the radius of a U type hook (Mild steel)?


    1. 4 times the diameter
    2. 3 times the diameter
    3. 2 times the diameter
    4. none of the above

    View Answer
    Answer: c
    As per IS 2502, Fig 1, (Note), the radius is "KD" and K is 2 for mild steel and 4 for HYSD bar.

  14. When the splices are welded in compression then the strength of the weld is taken as ...


    1. 100 % of the design strength of the joined bars
    2. 80 % of the design strength of the joined bars
    3. 90 % of the design strength of the joined bars
    4. 750 % of the design strength of the joined bars

    View Answer
    Answer: a
    As per IS 456, Cl 26.2.5.2, it is 100 % of the design strength of the joined bars when the splices are in compression.
    If the bars are spliced in tension then the strength of weld is 80 % of the design strength of the welded bars and 100 % of design strength of the mechanical connection.





By on
Labels:

No comments:

Post a Comment

Subscribe to: Post Comments (Atom)