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Civil Engineering :: Concrete Technology

  1. For quality control of Portland cement, the test essentially done is

  2. A.

    setting time

    B.
    soundness
    C.

    tensile strength

    D.

    consistency

    E.

    all the above.


  3. If 1500 g of water is required to have a cement paste 1875 g of normal consistency, the percentage of water is,

  4. A.

    20%

    B.

    25%

    C.

    30%

    D.

    35%

    E.

    40%


  5. Under normal conditions using an ordinary cement, the period of removal of the form work, is

  6. A.

    7 days for beam soffits

    B.

    14 days for bottom slabs of spans 4.6 m and more

    C.

    21 days for bottom beams over 6 m spans

    D.

    2 days for vertical sides of columns

    E.

    all the above.


  7. Wp and Wf are the weights of a cylinder containing partially compacted and fully compacted concrete. If the compaction factor  is 0.95, the workability of concrete is

  8. A.

    extremely low

    B.

    very low

    C.

    low

    D.

    high

    E.

    none of these.


  9. For given water content, workability decreases if the concrete aggregates contain an excess of

  10. A.

    thin particles

    B.

    flat particles

    C.

    elongated particles

    D.
    flaky paticles
    E.

    all the above.


  11. M10 grade of concrete approximates

  12. A.

    1 : 3 : 6 mix

    B.
    1 : 1 : 2 mix
    C.

    1 : 2 : 4 mix

    D.
    1 : 1.5 : 3 mix
    E.

    none of these.


  13. For ensuring quality of concrete, use

  14. A.

    single sized aggegates

    B.

    two sized aggregate

    C.
    graded aggregates
    D.

    coarse aggregates.


  15. According to I.S. : 456, the number of grades of concrete mixes, is

  16. A.

    3

    B.

    4

    C.

    5

    D.

    6

    E.

    7


  17. The mixture of different ingredients of cement, is burnt at

  18. A.

    1000°C

    B.

    1200°C

    C.
    1400°C
    D.

    1600°C

    E.

    1800°C


  19.  

    The risk of segregation is more for

  20. A.

    wetter mix

    B.

    larger proportion of maximum size aggregate

    C.
    coarser grading
    D.
    all the above.