Civil Engineering - Concrete Technology MCQs Part 4
1. Concrete gains strength due to
A.
chemical reaction of cement with sand and coarse aggregates
chemical reaction of cement with sand and coarse aggregates
B.
evaporation of water from concrete
evaporation of water from concrete
C.
hydration of cement
hydration of cement
D.
All the above.
All the above.
Answer Option C
2. If aggregates completely pass through a sieve of size 75 mm and are retained on a sieve of size 60 mm, the particular aggregate will be flaky if its minimum dimension is less than
A.
20.5 mm
20.5 mm
B.
30.5 mm
30.5 mm
C.
40.5 mm
40.5 mm
D.
50.5 mm
50.5 mm
E.
none of these.
none of these.
Answer Option C
3. Non-uniform compaction may cause the concrete
A.
porous
porous
B.
non-homogeneous
non-homogeneous
C.
reduced strength
reduced strength
D.
all the above.
all the above.
Answer Option D
4. Log Angles machine is used to test the aggregate for
A.
crushing strength
crushing strength
B.
impact value
impact value
C.
abrasion resistance
abrasion resistance
D.
water absorption
water absorption
E.
none of these.
none of these.
Answer Option C
5. If fineness modulus of sand is 2.5, it is graded as
A.
very fine sand
very fine sand
B.
fine sand
fine sand
C.
medium sand
medium sand
D.
coarse sand
coarse sand
E.
very coarse sand.
very coarse sand.
Answer Option B
6. Pozzolanic properties exist in
A. shales
B. fly ash
C. pumicite
D. diatomaceous clay
E. all the above.
Answer Option E
7. An aggregate which passes through 25 mm I.S. sieve and is retained on 20 mm sieve, is said to be flaky if its least dimension is less than
A. 22.5 mm
B. 18.5 mm
C. 16.5 mm
D. 15.5 mm
E. 13.5 mm.
Answer Option E
8. Expansion joints are provided if the length of concrete structures exceeds
A. 10 m
B. 15 m
C. 15 m
D. 35 m
E. 45 m
Answer Option E
9. Workability improved by adding
A. fly ash
B. hydrated lime
C. calcium chloride
D. bentonite
E. all the above.
Answer Option E
10. If the slump of a concrete mix is 60 mm, its workability is
A. very low
B. low
C. medium
D. high
E. none of these.
Answer Option C
11. Pick up the correct statement from the following:
A. Sand obtained from pits, is washed to remove clay and silt
B. Sand obtained from flooded pits, need not be washed before use
C. Sea shore sand contains chlorides which cause effloresance
D. The chloride in sea shore sand and shingle may cause corrosion of reinforcement if the concrete is porous
E. All the above.
Answer Option E
12. The strength and quality of concrete, depend upon:
A. grading of aggregates
B. surface area of aggregates
C. shape of aggregates
D. surface texture of aggregates
E. all the above.
Answer Option E
13. The process of mixing, transporting, placing and compacting concrete using Ordinary Port land Cement should not take more than
A. 30 minutes
B. 40 minutes
C. 60 minutes
D. 75 minutes
E. 90 minutes.
Answer Option A
14. Pick up the incorrect statement from the following. While performing preliminary test on concrete
A. proportions of the material and water should be the same as to be used at the work site
B. cement should be mixed by hand in order to maintain uniformity
C. concrete mix should be stored in air-tight containers
D. concrete ingredients should be kept at a temperature of 37° ± 2°C
E. none of these.
Answer Option D
15. Sand requiring a high water cement ratio, belongs to
A. Zone I
B. Zone II
C. Zone III
D. Zone IV.
Answer Option A
16. Ordinary Portland cement is manufactured from
A. lime stone and clay
B. gypsum and lime
C. pozzolana
D. lime, pozzolana and clay.
Answer Option B
17. A flaky aggregate is said to be elongated if its length is
A. equal to the mean size
B. twice the mean size
C. thrice the mean size
D. four times the mean size
E. five times the mean size.
Answer Option B
18. To prevent segregation, the maximum height for placing concrete, is
A. 100 cm
B. 125 cm
C. 150 cm
D. 200 cm
E. 250 cm
Answer Option C
19. If the various concrete ingredients i.e. cement, sand and aggregates are in the ratio of 1:3:6, the grade of concrete, is
A. M 100
B. M 150
C. M 200
D. M 250
E. M 300
Answer Option A
20. Water cement ratio is generally expressed in volume of water required per
A. 10 kg
B. 20 kg
C. 30 kg
D. 40 kg
E. 50 kg
Answer Option E
21. For a good concrete
A. aggregates should be hard and durable
B. cement should be sufficient to produce the required strength
C. water should be free from organic materials
D. mixing of ingredients should be done thoroughly so as to produce homogeneity
E. All the above.
Answer Option E
22. If the effective plan area of a warehouse is 54 sq. m, and maximum height of piles permitted is 270 cm, the number of cement bags to be stored, is
A. 2000 bags
B. 2200 bags
C. 2400 bags
D. 2700 bags
E. 3000 bags
Answer Option D
23. Gypsum is added for
A. colour
B. strength
C. controlling setting time
D. none of these.
Answer Option C
24. A concrete having a slump of 6.5 cm, is said to be
A. dry
B. earth moist
C. semi-plastic
D. plastic
E. none of these.
Answer Option D
25. Strength of concrete with passage of time
A. increases
B. decreases
C. fluctuates
D. remains constant.
Answer Option A
26. Cement used for normal concrete construction, is obtained by burning a mixture of
A. silicious and argillaceous materials
B. argilaceous and calcareous materials
C. silicious and catcareous materials
D. silicious, argillaceous and calcareous materials
E. none of these.
Answer Option D
27. Pick up the correct statement from the following:
A. The concrete gains strength due to hydration of cement
B. The concrete cured at a temperature below 23°C, gains strength up to 28 days
C. The concrete does not set at freezing point
D. The strength of concrete increases with its age
E. All the above.
Answer Option E
28. Pick up the incorrect statement from the following:
A. Admixtures accelerate hydration
B. Admixtures make concrete water proof
C. Admixtures make concrete acid proof
D. Admixtures give high strength
E. None of these.
Answer Option A
29. Higher workability of concrete is required if the structure is
A. made with cement concrete
B. thick and reinfored
C. thin and heavily reinforced
D. thick and heavily reinfored.
Answer Option D
30. Setting time of cement increases by adding
A. gypsum
B. hydrogen peroxide
C. calcium chloride
D. sodium oxide
E. none of these.
Answer Option A
31. The dimensions of a 35 litre forma for measuring aggregates by volume, are :
A. length 30 cm, breadth 25 cm, height 30 cm
B. length 39 cm, breadth 25 cm, height 32 cm
C. length 27 cm, breadth 27 cm, height 48 cm
D. length 220 cm, breadth 25 cm, height 40 cm
E. none of these.
Answer Option C
32. The shuttering of a hall measuring 4 m x 5 m, can be removed after
A. 5 days
B. 7 days
C. 10 days
D. 14 days
E. 21 days
Answer Option B
33. Pick up the correct statement from the following:
A. There should not be any loss of cement from the charged drum of the mixer
B. Cement should be mixed for at least one minute
C. 10% of water is placed in the rotating drum before adding dry material
D. 10% of water is added after placing the other ingredients in the drum
E. All the above.
Answer Option E
34. If 50 kg of fine aggregates and 100 kg of coarse agregates are mixed in a concrete whose water cement ratio is 0.6, the weight of water required for harsh mix, is
A. 8 kg
B. 10 kg
C. 12 kg
D. 14 kg
E. 15 kg.
Answer Option C
35. The entrained air in concrete
A. increases workability
B. decreases workability
C. decreases resistance to weathering
D. increases strength
E. neither affects workability nor strength.
Answer Option A
36. Pick up the incorrect statement from the following:
A. Tricalcium silicate (C3S) hydrates rapidly
B. Tricalcium silicate (C3S) generates more heat of hydration
C. Tricalcium silicate (C3S) develops early strength
D. Tricalcium silicate (C3S) has more resistance to sulphate attack
E. None of these.
Answer Option D
37. Permissible compressive strength of M 200 concrete grade is
A. 100 kg/cm2
B. 150 kg/cm2
C. 200 kg/cm2
D. 250 kg/cm2
E. 300 kg/cm2
Answer Option C
38. In slump test, each layer of concrete is compacted by a steel rod 60 cm long and of 16 mm diameter for
A. 20 times
B. 25 times
C. 30 times
D. 40 times
E. 50 times
Answer Option B
39. If the average compressive strength is 4000 kg/cm2 and standard deviation is 500, the co-efficient of variation is
A. 10%
B. 12.5%
C. 15%
D. 18.5 %
E. 20%
Answer Option B
40. For preparing ordinary concrete, the quantity of water used, is
A. 5% by weight of aggregates plus 20% of weight of cement
B. 10% by weight of aggregates plus 10% of weight of cement
C. 5% by weight of aggregates plus 30% of weight of cement
D. 30% by weight of aggregates plus 10% of weight of cement
E. none of these.
Answer Option C
41. According to IS : 382-1963, a good aggregate should be
A. chemically inert
B. sufficiently strong
C. hard and durable
D. all the above.
Answer Option D
42. The 28 days cube strength of mass concrete using aggregates of maximum size 5 cm for gravity dams should be
A. between 150 to 300 kg/cm2
B. between 350 to 600 kg/cm2
C. between 150 to 500 kg/cm2
D. below 200 kg/cm2
E. none of these.
Answer Option D
43. If P, Y and Z are the weights of cement, fine aggregates and coarse aggregates respetively and W/C is the water cement ratio, the minimum quantity of water to be added to first batch, is obtained by the equation
A. 0.1P + 0.3Y + 0.1Z = W/C x P
B. 0.3P + 0.1Y + 0.01Z = W/C x P
C. 0.4P + 0.2Y + 0.01Z = W/C x P
D. 0.5P + 0.3Y + 0.01Z = W/C x P
E. 0.2P + 0.5Y + 0.1Z = W/C x P
Answer Option B
44. For the construction of thin R.C.C. structures, the type of cement to be avoided, is
A. ordinary Portland cement
B. rapid hardening cement
C. low heat cement
D. blast furnace slag cement
E. sulphate resisting cement.
Answer Option D
45. Vicat apparatus is used for
A. fineness test
B. consistency test
C. test for setting time
D. test for tensile strength
E. none of these.
Answer Option B
46. Pick up the incorrect statement from the following:
A. Space between the exterior walls of a warechouse and bag piles should be 30 cm
B. Cement bags should preferably be piled on wooden planks
C. Cement bags should be placed such that bags of one layer does not touch the bags of the adjacent layer
D. Width and height of the pile should not exceed 3 m and 2.70 m respectively
E. None of these.
Answer Option E
47. For the construction of the retaining structures, the type of concrete mix to be used, is
A. 1 : 3 : 6
B. 1 : 2 :4
C. 1 : : 3
D. 1 : l : 2
E. 1 : 4 : 8.
Answer Option C
48. An ideal ware house, is provided
A. water proof masonry walls
B. water proof roof
C. few windows which remain generally closed
D. 15 cm thick concrete floor laid on a dry course of soling
E. all the above.
Answer Option E
Comments
Post a Comment