Concrete Technology 70 Questions with Answers
1.
The
strength and durability of concrete depends upon
A. Size
of aggregates
B. Grading
of aggregates
C. Moisture
contents of aggregates
D. All
of these
Answer: Option D
2.
The continuous strain, which the concrete
undergoes due to application of external loads, is called
A. Workability
B. Bleeding
C. Segregation
D. Creep
Answer: Option D
3.
The type of lime used in lime concrete is
A. Fat
lime
B. Poor
lime
C. Slaked
lime
D. Hydraulic
lime
Answer: Option D
4.
Reinforced cement concrete is equally strong
in taking
A. Tensile
and compressive stresses
B. Compressive
and shear stresses
C. Tensile,
compressive and shear stresses
D. Tensile
and shear stresses
Answer: Option C
5.
For heat and sound insulation purposes, we
shall use
A. Vacuum
concrete
B. Air-entrained
concrete
C. Saw
dust concrete
D. Both
(a) and (b)
Answer: Option B
6.
The removal of excess air after placing
concrete helps in increasing the strength of concrete by
A. 15 to 20% B. 20
to 30%
C. 30 to 50% D. 50 to 70%
Answer: Option A
7.
A suitable admixture added at the time of
preparing the concrete mix, makes the concrete
A. Water-proof
B. Acid
proof
C. Highly
strong
D. All
of these
Answer: Option D
8.
In the manufacture of cement, the dry or wet
mixture of calcareous and argillaceous materials is burnt at a temperature between
A. 9000
C to 10000 C
B. 10000
C to 12000 C
C. 12000
C to 15000 C
D. 15000
C to 16000 C
Answer: Option D
9.
The chemical ingredient of cement which provides
quick setting property to the cement is
A. Lime B. Silica
C. Alumina D. Iron oxide
Answer: Option C
10. The gypsum is added to the cement
for
A. Providing
high strength to the cement
B. Controlling
the initial setting time of cement
C. Lowering
the clinkering temperature of cement
D. All
of the above
Answer: Option B
11. Lime when added in excess
quantity
A. Makes
the cement unsound
B. Causes
the cement to expand and disintegrate
C. Lowers
the clinkering temperature of cement
D. Both
(a) and (b)
Answer: Option D
12. In order to provide colour,
hardness and strength to the cement, the ingredient used is
A. Lime B. Silica
C. Alumina D. Iron oxide
Answer: Option D
13. Efflorescence in cement is caused
due to the excess of
A. Silica B. Lime
C. Alkalies D.
Iron oxide
Answer: Option C
14. The presence of tricalcium
silicate in cement
A. Hydrates
the cement rapidly
B. Generates
less heat of hydration
C. Offers
high resistance to sulphate attack
D. All
of these
Answer: Option A
15. High percentage of tricalcium
silicate and low percentage of percentage of dicalcium silicate in cement
results in
A. Rapid
hardening
B. High early strength
C. High heat generation
D. All of these
Answer: Option D
16. Rapid hardening cement is used
A. Where
high early strength is desired
B. Where
form work is to be removed as early as possible
C. For
constructing road pavements
D. All
of the above
Answer: Option D
17. Blast furnace slag cement is used
for
A. Dams
B. Bridge
abutments
C. Retaining
resisting cement
D. All
of these
Answer: Option D
18. For a structure subjected to the
action of sea water, the cement used is
A. Rapid
hardening cement
B. Low
heat cement
C. High
alumina cement
D. Sulphate
resisting cement
Answer: Option C
19. The strength of concrete using
air entraining cement gets reduced by
A. 5 to 10% B. 10
to 15%
C. 15 to 20% D. 20 to 25%
Answer: Option B
20. The degree of grinding of cement
is called
A. Fineness
B. Soundness
C. Impact
value
D. Bulking
Answer: Option A
21. The phenomenon by virtue of which
the cement does not undergo large change in volume when treated with water, is
known as
A. Fineness
B. Soundness
C. Setting
time
D. None
of these
Answer: Option B
22. The fineness of cement is
measured in terms of
A. Percentage
weight retained on IS sieve number 9
B. Surface
area in cm2 per gram of the cement
C. Either
(a) or (b)
D. None
of these
Answer: Option C
23. Vicat’s apparatus is used to perform
A. Fineness
test
B. Soundness
test
C. Consistency
test
D. Compressive
strength test
Answer: Option C
24. To perform the initial setting
time test, the water is added to the cement at the rate of by weight of cement.
A. 0.72 P B. 0.78 P
C. 0.85 P D. 0.95 P
Answer: Option C
25. The percentage of water for
making a cement paste of normal consistency varies from
A. 15 to 25% B. 25
to 35%
C. 35 to 50% D. 50 to 60%
Answer: Option B
26. Le-chatelier apparatus is used to
perform
A. Fineness test B. Soundness test
C. Consistency test D.
Compressive strength test
Answer: Option B
27. To perform the compressive
strength test of cement, water is called at the rate of
A. 0.72
P + 3% of water
B. 0.85
P + 4% of water
C. P
+ 3% of water
D. P
+ 4% of water
Answer: Option C
28. Initial setting time of ordinary
Portland cement is
A. 15 min B. 30
min
C. 60 min D. 10 h
Answer: Option B
29. The cubes of cement prepared for
compressive strength test should be kept at a temperature of in an atmosphere
of at least 90% relative humidity for 24 hours.
A. 150 ± 20 C B. 210
± 20 C
C. 270 ± 20 C D. 300
± 20 C
Answer: Option C
30. The inert mineral material used
for the manufacture of mortars and concretes is
A. Cement B.
Water
C. Aggregate D. Admixture
Answer: Option C
31. The material having particle size
varying from 0.002 to 0.06 mm is termed as
A. Silt B. Clay
C. Sand D. None of these
Answer: Option A
32. The aggregate which pass through
75 mm IS sieve and entirely retain on 4.75 mm IS sieve is known as
A. Cyclopean
aggregate
B. Coarse
aggregate
C. Fine
aggregate
D. All-in-aggregate
Answer: Option B
33. The aggregate is said to be flaky
when
A. Its
least dimension is three-fifth of its means dimension
B. Its
least dimension is equal to its means dimension
C. Its
length is equal to its means dimension
D. Its
length is equal to 1.8 times its means dimension
Answer: Option A
34. An aggregate having all the pores
filled with water but having dry surface is called
A. Very
dry aggregate
B. Dry
aggregate
C. Saturated
surface dry aggregate
D. Moist
aggregate
Answer: Option C
35. The sum of percentages of all
deleterious material in the aggregate shall not exceed
A. 5% B. 10%
C. 15% D.
20%
Answer: Option A
36. Bulking of sand is
A. Compacting
of sand
B. Segregating
sand particular size
C. Increase
in volume of sand due to presence of moisture upto certain extent
D. None
of the above
Answer: Option C
37. The fineness modulus of an
aggregate is roughly proportional to
A. Specific
gravity of the aggregate
B. Shape
of the aggregate
C. Average
size of particles in the aggregate
D. Grading
of the aggregate
Answer: Option C
38. The value of fineness modulus for fine sand may range
between
A. 1.1 to 1.3 B. 1.3
to 1.6
C. 1. to 2.2 D. 2.2 to 2.6
Answer: Option D
39. The presence of calcium chloride
in water
A. Accelerates
setting of cement
B. Accelerates
hardening of cement
C. Causes
little effect on quality of concrete
D. All
of these
Answer: Option A
40. The admixtures are added in
concrete to
A. Accelerate
the rate of setting and hardening of cement
B. Make
the concrete water proof, acid proof etc.
C. Reduce
the bleeding and segregation of concrete mix
D. All
of the above
Answer: Option D
41. The standard sand now used in
Indian is obtained from
A. Ennore (Chennai) B. Mumbai
C. Orissa D.
Jaipur
Answer: Option A
42. Excess quantity of water
A. Makes
the concrete mix harsh
B. Makes
the concrete mix unworkable
C. Causes
segregation in concrete
D. Causes
bleeding in concrete
Answer: Option C
43. The rule of water cement ratio
was established by
A.
Duff Abram
B. Plowman
C. W. Simms
D. Dr. Karl Terzaghi
Answer: Option A
44. Hydration of cement is due to the
chemical action of water with
A. Dicalcium
silicate
B. Tricalcium
silicate
C. Tricalium
aluminate
D. All
of these
Answer: Option D
45. For the improvement of workability
of concrete, the shape of aggregate recommended is
A. Irregular B. Angular
C. Round D.
Flaky
Answer: Option C
46. The use of air-entraining agents
in concrete
A. Increases
workability agents in concrete
B. Decreases
bleeding
C. Decreases
strength
D. All
of these
Answer: Option D
47. The top diameter, bottom diameter
and height of the mould used for slump test are respectively
A. 100
mm, 200 mm, 300 mm
B. 200
mm, 100 mm, 300mm
C. 200
mm, 300 mm, 100 mm
D. 100
mm, 300 mm, 200mm
Answer: Option A
48. The slump test of concrete is slump
test is expressed as
A. Consistency
B. Mobility
C. Homogeneity
D. All
of these
Answer: Option A
49. A compaction factor of 0.88
indicates that the workability of considered of concrete mix is
A. Very low B. Low
C. Medium D. High
Answer: Option C
50. As per IS : 459-1978, the
concrete mixes are designated into
A. 4 grades B. 5
grades
C. 6 grades D. 7 grades
Answer: Option D
51. After moulding, the test
specimens of trial mix are placed at a temperature of
A. 10 ± 20 C B. 15 ±
20 C
C. 23 ± 20 C D.
27 ± 20C
Answer: Option D
52. In preliminary test, the concrete
is placed in the mould in layers of equal volume
A. Two B. Three
C. Four D. Five
Answer: Option C
53. The preliminary test should be
repeated if the difference of compressive strength of three test specimens
exceeds
A. 0.5 N/mm2 B. 1
N/mm2
C. 1.5 N/mm2 D. 2 N/mm2
Answer: Option C
54. The minimum quantity of cement to
be used in controlled concrete is specified as
A. 120 kg/cm3 B. 160
kg/cm3
C. 220 kg/cm2 D.
280 kg/cm2
Answer: Option C
55. The ordinary concrete is not used
for grade of concrete mix.
A. M 10 B. M 20
C. M 25 D. M 40
Answer: Option D
56. The water used for ordinary
concrete is equal to 5% by weight of aggregate plus by weight of cement
A. 10% B. 20%
C. 30% D.
40%
Answer: Option C
57. The concrete can be lifted by
pumps through a maximum vertical distance of
A. 10 m B. 20 m
C. 30 m D. 50 m
Answer: Option D
58. The diameter of the pipe line
used for transportation of concrete by pumps should not exceed
A. 10 cm B. 20 cm
C. 30 cm D. 40 cm
Answer: Option C
59. To prevent segregation, the
concrete should not be thrown from a height of more than
A. 1/2 m B. 1 m
C. 1.5 m D. 2 m
Answer: Option A
60. The process of consolidating
concrete mix after placing it in position is termed as
A. Curing
B. Wetting
C. Compaction
D. None
of these
Answer: Option C
61. For compacting large section of
mass concrete in structures, the type of vibrator used is
A. Internal
vibrator
B. Screed
vibrator
C. Form
vibrator
D. All
of these
Answer: Option A
62. For compacting plain concrete or
one-way reinforced concrete floors, the vibrator used is
A. Internal
vibrator
B. Screed
vibrator
C. Form
vibrator
D. All
of these
Answer: Option B
63. The final operation of finishing
the concrete surface is called
A. Screeding
B. Floating
C. Trowelling
D. None
of these
Answer: Option C
64. The process of hardening the
concrete mixes by keeping its surface moist for a certain period is called
A. Floating
B. Curing
C. Screeding
D. None
of these
Answer: Option B
65. Vertical sides of columns may be
stripped after
A. 1
to 2 days
B. 7
days
C. 14
days
D. 21
days
Answer: Option A
66. The construction joints in cement
concrete
A. Should
be located where bending moment is large
B. Should
be located where shear force is large
C. Should
not be provided at the corners
D. Should
be spaced at a distance of 3 m apart in case of huge structures
Answer: Option C
67. Segregation in concrete results
in
A.
Honey combing
B.
Porous layers
C.
Surface scaling
D.
All of these
Answer: Option
D
68. The cement concrete in which high
compressive stresses are artificially induced without
A.
Plain cement concrete
B.
Reinforced cement concrete
C.
Prestressed cement concrete
D.
Lime concrete
Answer: Option
C
69. The light-weight concrete is
prepared by
A.
Mixing Portland cement with sawdust in specified
proportion in the concrete
B. Using
coke-breeze, cinder or slag as aggregate in the concrete
C. Mixing
aluminium in the concrete
D. None of the above
Answer: Option
B
70. In making precast structural
units for partition and wall lining purposes, the concrete should be
A.
Sawdust concrete
B.
Air-entrained concrete
C.
Light-weight concrete
D.
Vacuum concrete
Answer: Option
C
No comments:
Post a Comment