Important Questions of BMC

Pankaj Sharma

Royal Member
Staff member
1.If p is the standard consistency of cement the amount of water used in conducting the initial setting time test on cement is

a)0.65 p

b) 0.85 p

c) 0.6 p

d) 0.8 p

2.For complete hydration of cement the w/c ratio needed is

a)less than 0.25

b)more than 0.25 but less than 0.35

c)more than 0.35 but less than 0.45

d)more than 0.45 but less than 0.60

3.Blast furnace slag has approximately

a)45% calcium oxide and about 25% silica

b)50% alumina and 20% calcium oxide

c)25% magnesia and 15% silica

d)25% calcium sulphate and 15% alumina

4.Gypsum is used as an admixture in cement grouts for

a)accelerating the setting time

b)retarding the setting time

c)increasing the plasticity

d)reducing the grout shrinkage

5.Which of the following pairs in respect of ordinary Portland cement (OPC ) are correctly matched.

1. Initial setting time ……30 minutes

2. Final setting time …….10 hours

3. Normal consistency ……10%

Select the correct answer from the codes given below:

a) 1, 2 and 3

b) 2 and 3

c) 1 and 2

d) 1 and 3

6.High alumina cement is produced by fusing together a mixture of

a)Limestone and bauxite

b)Limestone, bauxite and gypsum

c)Limestone, gypsum and clay

d)Limestone, gypsum, bauxite, clay and chalk

7.The temperature range in a cement kiln is

a)500 to 1000 °C

b) 1000 to 1200°C

c)1300 to 1500°C

d) 1600 to 2000°C

8.Before testing setting time of cement one should test for


b) Strength

c) Fineness

d) consistency

9.The role of superplasticizer in a cement paste is to

a)Disperse the particles

b)Disperse the particles and to remove air bubbles

c)Disperse the particles, remove air bubbles and to retard setting

d)Retard setting

10.Increase the fineness of cement

a)Reduces the rate of strength development and leads to higher shrinkage

b)Increases the rate of strength development and reduces the rate of deterioration

c)Decreases the rate of strength development and increases the bleeding of cement.

d)Increases the rate of strength development and leads to higher shrinkage

11.The fineness of cement is tested by

a)air-content method

b)air-permeability method

c)Le-Chatelier apparatus

d)Vicat’s apparatus

12.For marine works, the best suited cement is

a)Low heat Portland cement

b)Rapid hardening cement

c)Ordinary portland cement

d)Blast furnace slag cement

13.The proper size of mould for testing compressive strength of cement is

a)7.05 cm cube

b) 10.05 cm cube

c)15 cm cube

d) 12.05 cm cube

14.The specific gravity of commonly available ordinary Portland cement is



c) 2.05

d) 1.83

15.Consider the following statements:
Low percentage of C3S and high percentage of C2S in cement will result in

1.Higher ultimate strength with less heat generation


3.Better resistance to chemical attack.

Which of the statements given above are correct?

a)1 and 2

b) 2 and 3

c) 1 and 3

d) 1, 2 and 3

16.Match List-I (Apparatus) with List-II (Purpose) and select the correct answer using the code givenbelow the Lists:



B. Vicat Needle with annular collar

C. Vee-Bee

D. Briquettes test machine


1. Workability of concrete

2. Soundness of cement

3. Tensile strength of cement

4. Final setting time of cement

Codes: A B C D

a) 1 3 2 4

b) 2 4 1 3

c) 1 4 2 3

d) 2 3 1 4

17. Ultimate strength of cement is influenced by which one of the following?

a) Tricalcium silicate

b) Dicalcium silicate

c) Tricalcium aluminate

d) Tetracalciumalumino-ferrite

18. As per specifications, the initial setting time of ordinary Portland cement should not be less than

a) 10 minutes

b) 20 minutes

c) 30 minutes

d) 60 minutes

19.In cements, generally the increase in strength during a period of 14 days to 28 days is primarily due to

a) C3A


c) C3S


20. What is the requirement of water (expressed as % of cement w/w) for the completion of chemical reactions in the process of hydration of OPC?

(a) 10 to 15%

(b) 15 to 20%

(c) 20 to 25%

(d) 25 to 30%

21. If P is the percentage of water required for determination of normal consistency of cement, then percentage of water to be added for determination of initial setting time is

(a) 0.70 P

(b) 0.75 P

(c) 0.80 P

(d) 0.85 P

22. A cement bag contains 0.035 cubic meter of cement by volume. How many bags will one tonne of cement comprise?

(a) 16

(b) 17

(c) 18

(d) 20

23. Match List-I (Grade of cement & Age) with List-II (Compressive strength in N/mm2) and select the correct answer using the code given below the lists:


A. Grade 33 (7 days)

B. Grade 43 (28 days)

C. Grade 53 (3 days)

D. Grade 43 (7 days)


1. 27
2. 43
3. 22
4. 33



(a) 4 2 1 3

(b) 3 2 1 4

(c) 4 1 2 3

(d) 3 1 2 4

24. If ‘W’ is the percentage of water required for normal consistency of cement, water to be added for determination of initial setting time is

(a) 0.50 W
(b) 0.62 W
(c) 0.75 W
(d) 0.85 W

25. Soundness test of cement is carried out to determine is

(a) alumina content

(b) iron oxide content

(c) free lime content

(d) durability under sea water

26. Fineness of cement is measured in the units of

(a) volume/mass

(b) mass/volume

(c) area/mass

(d) mass/area

27. The initial setting time of cement depends most on

(a) tricalcium aluminate

(b) tricalcium silicate

(c) tricalcium aluminoferrite

(d) dicalcium silicate

28. Which compound of cement is responsible for strength of cement?

(a) Magnesium oxide

(b) Silica

(c) Alumina

(d) Calcium sulphate

29. Which type of cement is recommended in large mass concrete works such as a dam?

(a) Ordinary Portland

(b) High Alumina

(c) Low-heat Portland

(d) Portland Pozzolana

30. One bag of Portland cement, 50 kg in weight, would normally have a bulk volume of

(a) 30 L

(b) 35 L

(c) 40 L

(d) 45 L

31. The split tensile strength of M15 grade concrete when expressed as a percentage of its compressive strength is

(a) 10 to 15%

(b) 15 to 20%

(c) 20 to 25%

(d) 25 to 30%

32. The approximate ratio between the strength of cement concrete at 7 days and 28 days is

(a) ¾

(b) 2/3

(c) ½

(d) 1/3

33. Modulus of elasticity of M25 concrete as determined by formula of IS 456 is

(a) 1, 42, 500 MPa

(b) 90,125 MPa

(c) 28, 500 MPa

(d) 16, 667 MPa

34. Tensile strength of concrete is measured by

(a) direct tension test in the universal testing machine

(b) applying compressive load along the diameter of the cylinder

(c) applying third point loading on a prism

(d) applying tensile load along the diameter of the cylinder.

35. The approximate ratio of strength of 15 cm x 30 cm concrete cylinder to that of 15 cm cube of the same concrete is

(a) 1.25

(b) 1.00

(c) 0.85

(d) 0.50

36. Weigh-batching proceeds on

(a) the assumption of the declared weight in each bag of cement.

(b) weighing the contents of each bag

(c) accurately estimating the weight of each material to be used in each batch

(d) the assumption of correct dry weight of each size range of each material and the weight of water

37. The moisture content in structural timber should be

(a) less than 5%

(b) 5 to 10%

(c) 10 to 20%

(d) 15 to 25%

38. The optimum number of revolutions over which concrete is required to be mixed in a mixer machine is.

(a) 10

(b) 20

(c) 50

(d) 100

39. The ultimate strength of cold drawn steel wires

(a) increases with the increase in the diameter of the bar

(b) increases with reduction in the diameter of the bar

(c) Does not depend upon the change in the diameter of the bar

(d) Depends only on the diameter of the bar.

40. The ratio of Young’s modulus of high tensile steel to that of mild steel is about

(a) 0.5

(b) 1.0

(c) 1.5

(d) 2.0

41. Polyvinyl chloride (PVC) is a

(a) thermosetting material

(b) thermoplastic material

(c) elasto-plastic material

(d) rigid plastic material

42. General shrinkage in cement concrete is caused by

(a) carbonation

(b) stresses due to external load

(c) drying with starting with a stiff consistency

(d) drying with starting with a water consistency

43. The carbon of structural steel is

(a) Less than 0.1%

(b) 0.10 to 0.25%

(c) 0.25 to 0.60%

(d) 0.60 to 1.00%

44. A splitting tensile test is performed on a cylinder of diameter ‘D’ and length ‘L’ if the ultimate load is ‘P’, then the splitting tensile strength of concrete is given by

(a) P/πDL

(b) 2P/πDL

(c) 4PL/πD

(d) 2PL/πL

45. Batching refers to

(a) Controlling the total quantity at each batch

(b) Weighing accurately, the quantity of each material for a job before mixing

(c) Controlling the quantity of each material into each batch

(d) Adjusting water to be added in each batch according to the moisture content of the materials being mixed in the batch

46. To make one cubic metre of 1 : 2 : 4 by volume of concrete, the volume of coarse aggregates required is

(b) 0.95 m3

(b) 0.85 m3

(c) 0.75 m3

(d) 0.65 m3

47. The ratio of direct tensile strength to that of modulus of rupture of concrete is

(a) 0.25

(b) 0.5

(c) 0.75

(d) 1.0

48. As per I.S. Code of Practice, concrete should be cured at

(a) 5° C

(b) 10° C

(c) 27° C

(d) 45° C

49. Which one of the following types of concrete is most suitable in extreme cold climates?

(a) Air-entrained concrete

(b) Ready mix concrete

(c) Vacuum concrete

(d) Coarse concrete

50. Which one of the following aggregate gives maximum strength in concrete?

(a) Rounded aggregate

(b) Elongated aggregate

(c) Flaky aggregate

(d) Cubical aggregate

51. In building construction, the place for providing damp proof course is at the

(a) Basement level

(b) Window sill level

(c) Lintel level

(d) Roof level

52. What is the range of fineness modulus of sand which is least suitable for making good concrete?

(a) 3.5-4.5

(b) 2.9-3.2

(c) 2.6-2.9

(d) 2.2-2.6

53. Slump and compaction factors are two different measures of workability of concrete. For a slump of 0 to 20 mm, what is the equivalent range of compaction factor?

(a) 0.50-0.70
(b) 0.70-0.80
(c) 0.80-0.85
(d) 0.85-0.92

54. On which one of the following factors, does strength of concrete depend primarily?

(a) Quality of coarse aggregate

(b) Quality of fine aggregate

(c) Fineness of cement

(d) Water-cement ratio

55. The mix design for pavement concrete is based on

(a) the flexural strength

(b) The characteristics compressive strength

(c) The shear strength

(d) The bond strength

56. In what context is the slump test performed?

(a) Strength of concrete

(b) Workability of concrete

(c) Water-cement ratio

(d) Durability of concrete

57. Transportation of concrete-mix by pumps is very convenient method, particularly in case of

(a) Housing complex

(b) Cement concrete pavement

(c) Low-rise buildings

(d) Tunnel-lining

58. What is the correct sequence of operations involved in concrete production?

(a) Batching – Mixing – Handling – Transportation

(b) Mixing – Batching – Handling – Transportation

(c) Transportation – Handling – Mixing – Batching

(d) Handling – Transportation – Mixing – Batching

59. Which one of the following is the correct expression for the target mean strength ft of concrete mix?

(a) ft = k.fck

(b) ft = fck + ks

(c) ft = fck + S

(d) ft = kfck + k

60. What is the representative geometric mean size of an aggregate sample if its fineness modulus is 3.0?

(a) 150 m

(b) 300 m

(c) 600 m

(d) 12 m

61.. What is the ratio of flexural strength (fck) to the characteristic compressive strength of concrete (fck) for M25 grade concrete?

(a) 0.08

(b) 0.11

(c) 0.14

(d) 0.17

62. If one intends to obtain the best workability of concrete, the preferred shape of aggregate is

(a) round

(b) annual

(c) triangular

(d) flinty

63. According to the Indian Standard Specifications, concrete should be cured under a humidity of

(a) 90%

(b) 80%

(c) 70%

(d) 60%

64. Which of the following tests compares the dynamic modulus of elasticity of samples of concrete?

(a) Compression test

(b) Ultrasonic pulse velocity test

(c) Split test

(d) Tension test

65. A good brick should not absorb water by weight more than

(a) 10%

(b) 20%

(c) 25%

(d) 30%

66. The coefficient of linear expansion of granite is in the range of that of

(a) glass
(b) mild steel
(c) high carbon steel
(d) bamboo

67. A good brick when immersed in water bath for 24 hours should not absorb more than

(a) 20% of its dry weight

(b) 30% of its saturated weight

(c) 10% of its dry weight

(d) 20% of its saturated weight

68. For good bonding in brick masonry

(a) all bricks need not be uniform in size

(b) bats must be used in alternate courses only

(c) the vertical joints in alternate courses should fall in plumb

(d) cement mortar used must have surkhi as additive

69. Window sills in residential house are normally kept at

(a) 83 to 90 cm above the floor level

b) 80 to 90 cm above the floor level

(c) 78 to 88 cm above the floor level

(d) 75 to 85 cm above the floor level

70. For one cubic meetre of brick masonry, the number of modular bricks needed is

(a) 400 or less

(b) 400 to 450

(c) 500 to 550

(d) 600 to 650

71. In brick masonry.

(a) Mortar strength should match brick strength

(b) Mortar strength should exceed brick strength

(c) Brick strength should exceed mortar strength

(d) The strength of masonry and brick are independent

72. The crushing strength of a good building stone should be at least

(a) 50 MPa

(b) 100 MPa

(c) 150 MPa

(d) 200 MPa

73. The slenderness ratio for masonry walls should NOT be more than

(a) 50

(b) 40

(c) 30

(d) 20

74. The most important purpose of frog in a brick is to

(a) Emboss manufacture’s name

(b) Reduce the weight of brick

(c) Form key joint between brick and mortar

(d) Improve insulation by providing ‘hollows’

75. Bricks are burnt at a temperature range of

(a) 500° to 700°C

(b) 700° to 900°C

(c) 900° to 1200°C

(d) 1200° to 1500°C

76. A king closer is a

(a) Full brick

(b) ¾ brick

(c) longitudinally ½ brick

(d) crosswise ½ brick

77. The number of bricks required per cubic metre of brick masonry is

(a) 400

(b) 450

(c) 500

(d) 550

78. The maximum permissible slenderness ratio for masonry walls is

(a) 40

(b) 30

(c) 20

(d) 10

79. When the corner of a brick is removed along the line joining mid-points of adjoining sides, the portion left is called

(a) Closer

(b) Squint brick

(c) Queen closer

(d) King closer

80. The minimum compressive strength of first class bricks should be

(a) 5 N/mm2

(b) 7.5 N/mm2

(c) 9 N/mm2

(d) 10 N/mm2

81. Which one of the following is the correct statement?

Refractory bricks resist:

(a) high temperature

(b) chemical action

(c) dampness

(d) all of the above

82. What is the effective height of a free-standing masonry wall for the purpose of computing slenderness ratio?

(a) 0.5 L

(b) 1.0 L

(c) 2.0 L

(d) 2.5 L

83. When a 1st class brick is immersed in cold water for 24 hours, it should not absorb water by weight more than

(a) 15%

(b) 20%

(c) 25%

(d) 30%

84. The temperature at which the bricks are burnt in kiln varies from

(a) 500° to 800° C

(b) 800° to 1000°C

(c) 1000°to 1200°C

(d) 1200°C to 1500°C

85. Which one of the following is the nominal size of standard modular brick?

(a) 25 cm x 13 cm x 8 cm

(b) 25 cm x 10 cm x 8 cm

(c) 20 cm x 10 cm x 10 cm

(d) 20 cm x 15 cm x 10 cm

86. Why are bricks soaked in water before using in brick masonry?

(a) For removing dust

(b) For reducing air voids

(c) For preventing depletion of moisture from mortar

(d) For reducing efflorescence

87. In load-bearing wall, the depth of horizontal chassis should not exceed which one of the following?

(a) 1/3 thickness of masonry

(b) ¼ thickness of masonry

(c) 1/5 thickness of masonry

(d) 1/6 thickness of masonry

88. When a column is supported throughout its length either by masonry walls or by construction on all the sides, then its slenderness ratio is

(a) Infinite

(b) Zero

(c) Reasonably high

(d) Low

89. Maximum slenderness ratio for load-bearing masonry wall built in cement mortar, as per IS code, shall not exceed

(a) 13

(b) 20

(c) 27

(d) 30

90. The standard size of a brick is

(a) 20 cm x 10 cm x 10 cm

(b) 19 cm x 9 cm x 9 cm

(c) 18 cm x 9 cm x 9 cm

(d) 18 cm x 10 cm x 10 cm

91. As per IS classification, the minimum compressive strength of a first class brick should be

(a) 75 kg/cm2

(b) 100 kg/cm2

(c) 125 kg/cm2

(d) 150 kg/cm2

92. The compressive strength of heavy duty bricks, as per IS : 2980-1962, should be not less than

(a) 400 kg/cm2

(b) 175 kg/cm2

(c) 100 kg/cm2

(d) 75 kg/cm2

93. According to the relevant I.S code, the weight of the timber is to be reckoned at a moisture content of

(a) zero

(b) 4%

(c) 8%

(d) 12%

94. The strength of timber is maximum when load applied is

(a) parallel to grain

(b) perpendicular to grain

(c) inclined at 45 to grain

(d) inclined at 60 to grain

95. The nail diameter should not be more than (t= least thickness of the wooden member to be connected)

(a) t/6

(b) t/8

(c) t/10

(d) t/12

96. The expansion and shrinkage of plywoods are comparatively very low as

(a) they are held in position by adhesives

(b) they are glued under pressure

(c) plies are placed at right angles to each other

(d) they are prepared from veneers

97. Seasoning of timber is required to

(a) soften the timber

(b) harden the timber

(c) straighten the timber

(d) remove sap from the timber

98. The modulus of elasticity of timber is about

(a) 0.5 to 1.0 x 104 N/mm2

(b) 1.0 to 1.5 x 104 N/mm2

(c) 1.5 to 2.0 x 104 N/mm2

(d) 2.0 to 2.0 x 104 N/mm2

99. During the conversion of timber by sawing, in order to obtain strong timber pieces, the cut should be made by

(a) Ordinary sawing
(b) Tangential sawing
(c) Quarter sawing
(d) Radial sawing

100. Radial splits in timber originating from ‘Bark’ and narrowing towards the ‘Pith’ are known as
(a) Heart shakes
(b) Star shakes
(c) Cup shakes
(d) knots

101. The moisture content in a property seasoned timber will in the range of
(a) 5% to 8%
(b) 8% to 10%
(c) 10% to 12%
(d) 12% to 15%

102. The strength of timber is maximum in the direction

(a) Perpendicular to the grains

(b) Parallel to the grains

(c) 45° to the grains

(d) At all angles

103. On application of external stress on timbers, it behaves like

(a) An elastic material

(b) Non-elastic material

(c) Viscoelastic material

(d) Non-viscoelastic material

104. The ratio of tangential shrinkage to radial shrinkage of wood due to reduction in moisture content is

(a) In the range from 3.1 to 5.1

(b) In the range from 2 to 3

(c) In the range from 1 to 2

(d) Less than or equal to 1

105. Timber can be made reasonably fire-resistant by

(a) soaking it in Ammonium Sulphate

(b) coating with Tar plant

(c) pumping creosote oil into timber under high pressure

(d) seasoning process

106. A well-seasoned timber has a moisture content of about

(a) 15% to 20%

(b) 10% to 12%

(c) 5% to 8%

(d) 2% to 3%

107. Dry rot in timber is caused by

(a) Lack of ventilation

(b) Lack of light

(c) Immersion in water

(d) Alternative wet and dry atmosphere

108. Wood is impregnated with creosote oil in order to

(a) change its colour

(b) protect against fungi

(c) protect the annular layers

(d) fill up the pores

109. The timber preservative “creosote” belongs to the group of

(a) Water soluble salts

(b) Organic solvent type

(c) Tar oil type

(d) Inorganic solvent type

110. The strength of timber is maximum in a direction

(a) Parallel to the grains

(b) Perpendicular to the grains

(c) 450 to the grains

(d) 300 to the grains

111. Which one of the following is the most preferred wood for high quality and durable furniture?

(a) Sandalwood

(b) Deodar wood

(c) Teakwood

(d) Shisham wood

112. As a natural material, timber is which one of the following?

(a) Isotropic

(b) Anisotropic

(c) Homogeneous

(d) Sapwood

113. Shear strength of timber depends on which one of the following?

(a) Lignin with fibres

(b) Medullary rays

(c) Heartwood

(d) Sapwood

114. The defect which develops due to uncontrolled and non uniform loss of moisture from wood is known as which one of the following?

(a) Knot

(b) Shake

(c) Warping

(d) Cross grain

115. The moisture content of timber used in building frames can be

(a) 2% to 5%

(b 8% to 12%

(c) 12% to 18%

(d) > 20%

116. What is the ratio of the elastic modulus of structural timber in longitudinal direction to that in the transverse direction?

(a) ½ to 1

(b) 1/10 to 1/20

(c) 1 to 2

(d) 10 to 20

117. What is the modulus of elasticity of standard timber (Group in (MN/cm2)?

(a) 0.5 to 1.0

(b) 1.0 to 1.25

(c) 1.25 to 1.5

(d) 1.5 to 1.75

118. What is the treatment for marking timber fire-resistant?

(a) ASCU treatment

(b) Abel’s process

(c) Creosoting

(d) Tarring

119. The radial splits which are wider on the outside of the log and narrower towards the pith are known as

(a) star shakes

(b) annular rings

(c) cup shakes

(d) heart shakes

120. The age of a log of timber can be estimated by

(a) diameter of pith

(b) thickness of bark

(c) number of annular rings

(d) number of medullary rays

121. What treatment is adopted for making timber fire-resistant?

(a) ASCU treatment

(b) Abel’s process

(c) Creosoting

(d) Tarring

122. The plies in plywood are so placed that the grains of each ply are

(a) parallel to each other

(b) at right angle to one another

(c) 45o oblique to adjacent grain

(d) not constrained by any consideration

123. Which IS code is used for classification of timber for seasoning purposes?

(a) IS : 4970-1973

(b) IS : 1708-1969

(c) IS : 1141-1958

(d) IS : 399-1963

124. In paints, linseed oil is used as

(a) A thinner

(b) A drier

(c) A vehicle

(d) A water-proofing base

125. An arrangemenet for temporarily supporting a structure from beneath for safety, is known is

(a) Jacking

(b) Underpinning

(c) Supporting

(d) Hauling