1. To determine the modulus of rupture, the size of test specimen used is
a) 150 x150 x500 mm
b) 100 x100 x700 mm
c) 150 x150 x700 mm
d) 100 x100 x500 mm
2. The property of fresh concrete, in which the water in the mix tends to rise to the surface
while placing and compacting, is called
a) segregation
b) bleeding
c) bulking
d) creep
3. Select the incorrect statement
a) Lean mixes bleed more as compared to rich ones.
b) Bleeding can be minimized by adding pozzuolana finer aggregate.
c) Bleeding can be increased by addition 'of calcium chloride.
d) none of the above
4. The property of the ingredients to separate from each other while placing the concrete is
called
a) segregation
b) compaction
c) shrinkage
d) bulking
5. Workability of concrete is directly proportional to
a) aggregate cement ratio
b) time of transit
c) grading of the aggregate
d) all of above
6. Workability of concrete is inversely proportional to
a) time of transit
b) water-cement ratio
c) the air in the mix
d) size of aggregate
7. Approximate value of shrinkage strain in concrete, is
a) 0.003
b) 0.0003
c) 0.00003
d) 0.03
8. Air entrainment in the concrete increases
a) workability
b) strength
c) the effects of temperature variations
d) the unit weight
9. The relation between modulus of rupture fcr, splitting strength fcs and direct tensile
strength fct is given by
a) tcr -rcs = tct
b) fcr>fcs>fct.
C) fcr
d) fc5>fcr>fC.
10. The approximate value of the ratio between direct tensile strength and flexural strength
is
a) 0.33
b) 0.5
c) 0.75
d) 1.0
11. Strength of concrete increases with
a) increase in water-cement ratio
b) increase in fineness of cement
c) decrease in curing time
d) decrease in size of aggregate
12. The relation between modulus of rupture fcr and characteristic strength of concrete fck is
given by
a) fcr=0.35√fck
b) fcr=0.5√fck
c) fcr=0.7√fck
d) fcr=1.2√fck
where fcr and fck are in N/mm2'
13. The compressive strength of 100 mm cube as compared to 150 mm cube is always
a) less
b) more
c) equal
d) none of the above
14. According to IS : 456 -1978, the modulus of elasticity of concrete Ec (in N/mm2) can be
taken as
a) Ec = = 5700√fck
b) Ec = = 570√fck
c) Ec = = 5700√fck
d) Ec = 700√fck , fck is the characteristic strength in N/mm2
15. Increase in the moisture content in con-crete
a) reduces the strength
b) increases the strength
c) does not change the strength
d) all of the above
16. As compared to ordinary portland cement, use of pozzuolanic cement
a) reduces workability
b) increases bleeding
c) increases shrinkage
d) increases strength
17. Admixtures which cause early setting, and hardening of concrete are called
a) workability admixtures
b) accelerators
c) retarders
d) air entraining agents
18. The most commonly used admixture which prolongs the setting and hardening time is
a) gypsum
b) calcium chloride
c) sodium silicate
d) all of the above
19. The percentage of voids in cement is approximately
a) 25%
b) 40%
c) 60%
d) 80%
20. The strength of concrete after one year as compared to 28 days strength is about
a) 10 to 15% more
b) 15 to 20% more
c) 20 to 25% more
d) 25 to 50% more
21. As compared to ordinary portland cement, high alumina cement has
a) higher initial setting time but lower final setting time
b) lower initial setting time but higher final setting time
c) higher initial and final setting times
d) lower initial and final setting times
22. Modulus of rupture of concrete is a measure of
a) flexural tensile strength
b) direct tensile strength
c) compressive strength
d) split tensile strength
23. In order to obtain the best workability of concrete, the preferred shape of aggregate is
a) rounded
b) elongated
c) angular
d) all of the above
24. The effect of adding calcium chloride in concrete is
i) to increase shrinkage
ii) to decrease shrinkage
iii) to increase setting time
iv) to decrease setting time
The correct answer is
a) (i) and (iii)
b) (i)and(iv)
c) (ii) and (iii)
d) (ii) and (iv)
25. Bulking of sand is maximum if moisture content is about
a) 2 %
b) 4%
c) 6%
d) 10%
26. Finer grinding of cement
a) affects only the early development of strength
b) affects only the ultimate strength
c) both (a) and (b)
d) does not affect the strength
27. Poisson's ratio for concrete
a) remains constant
b) increases with richer mixes
c) decreases with richer mixes
d) none of the above
28. 1% of voids in a concrete mix would reduce its strength by about
a) 5%
b) 10 %
c) 15%
d) 20%
29. The fineness modulus of fine aggregate is in the range of
a) 2.0 to 3.5
b) 3.5 to 5.0
c) 5.0 to 7.0
d) 6.0 to 8.5
30. The factor of safety for
a) steel and concrete are same
b) steel is lower than that for concrete
c) steel is higher than that for concrete
d) none of the above
31. Examine the following statements
i) Factor of safety for steel should be based on its yield stress,
ii) Factor of safety for steel should be based on its ultimate stress,
iii) Factor of safety for concrete should be based on its yield stress,
iv) Factor of safety for concrete should be based on its ultimate stress.
The correct statements are
a) (i) and (iii)
b) (i)and(iv)
c) (ii) and (iii)
d) (ii) and (iv)
32. For a reinforced concrete section, the shape of shear stress diagram is
a) wholly parabolic
b) wholly rectangular
c) parabolic above neutral axis and rectangular below neutral axis
d) rectangular above neutral axis and parabolic below neutral axis
33. Diagonal tension in a beam
a) is maximum at neutral axis
b) decreases below the neutral axis and increases above the neutral axis
c) increases below the neutral axis and decreases above the neutral axis
d) remains same
34. If a beam fails in bond, then its bond strength can be increased most economically by
a) increasing the depth of beam
b) using thinner bars but more in number
c) using thicker bars but less in number
d) providing vertical stirrups
35. If nominal shear stress tv exceeds the design shear strength of concrete xc, the nominal
shear reinforcement as per IS : 456-1978 shall be provided for carrying a shear stress equal to
a) Ï„v
b) Ï„c
c) Ï„v - Ï„C
d) Ï„v + Ï„c
36. If the depth of actual neutral axis in a beam is more than the depth of critical neutral axis,
then the beam is called
a) balanced beam
b) under-reinforced beam
c) over-reinforced beam
d) none of the above
37. If the depth of neutral axis for a singly reinforced rectangular section is represented by kd in
working stress design, then the value of k for balanced section
a) depends on as, only
b) depends on aCbC only
c) depends on both crst and acbc
d) is independant of both ast and acbc where d is the effective depth, ast is permissible
stress in steel in tension and ocbc is permissible stress in concrete in bending compression.
38. If the permissible stress in steel in tension is 140 N/mm2, then the depth of neutral axis for
a singly reinforced rectangular balanced section will be
a) 0.35 d
b) 0.40 d
c) 0.45 d
d) dependent on grade of concrete also
39. Modulus of elasticity of steel as per IS : 456-1978 shall be taken as
a) 20 kN/cm2
b) 200 kN/cm2
c) 200kN/mm2
d) 2xl06N/cm2
40. Minimum grade of concrete to be used in reinforced concrete as per IS:456-1978 is
a) M15
b) M20
c) M 10
d) M25
41. For concreting of heavily reinforced sections without vibration, the workability of concrete
expressed as compacting factor should be
a) 0.75-0.80
b) 0.80-0.85
c) 0.85 - 0.92
d) above 0.92
42. Maximum quantity of water needed per 50 kg of cement for M 15 grade of concrete is
a) 28 litres
b) 30 litres
c) 32 litres
d) 34 litres
43. In case of hand mixing of concrete, the extra cement to be added is
a) 5%
b) 10%
c) 15%
d) 20%
44. For walls, columns and vertical faces of all structural members, the form work is generally
removed after
a) 24 to 48 hours
b) 3 days
c) 7 days
d) 14 days
45. The individual variation between test strength of sample should not be more than
a) ±5% of average
b) ± 10% of average
c) ± 15% of average
d) ±20% of average
46. One of the criteria for the effective width of flange of T-beam is bf =—+ bw +6Df 6 In above
formula, l0 signifies
a) effective span of T-beam
b) distance between points of zero mo-ments in the beam
c) distance between points of maximum moments in the beam
d) clear span of the T-beam
47. For a cantilever of effective depth of 0.5m, the maximum span to satisfy vertical deflection
limit is
a) 3.5 m
b) 4 m
c) 4.5 m
d) 5 m
48. For a simply supported beam of span 15m, the minimum effective depth to satisfy the
vertical deflection limits should be
a) 600 mm
b) 750 mm
c) 900 mm
d) more than 1 m
49. For a continuous slab of 3 m x 3.5 m size, the minimum overall depth of slab to satisfy
vertical deflection limits is
a) 50 mm
b) 75 mm
c) 100 mm
d) 120 mm
50. According to IS : 456-1978, the fiexural strength of concrete is
a) directly proportional to compressive strength
b) inversely proportional to compressive strength
c) directly proportional to square root of compressive strength
d) inversely proportional to square root of compressive strength
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