76. To obtain a very high strength concrete, use very fine grained
a) granite
b) magnetite
c) barite
d) volcanic scoria
77. Pick up the correct statement from the following:
a) sands obtained from pits, is washed to remove clay and silt
b) sands obtained from flooded pits, need not be washed before use
c) sea shore sands contain chloride which cause efflorescence
d) the chloride in sea shore sand and shingle may cause corrosion of reinforcement if the concrete is porous
e) all of the above
78. Pick up the correct statement from the following:
a) sand stones may be defined into calcareous, siliceous and ferruginous sand stones
b) concrete using sand stones, cracks due to excessive shrinkage
c) very hard and close grained crystallized lime stones are suitable aggregates but provide low strength
d) broken bricks produce a concrete having good fire resisting
qualities,
e) all of the above
79. The bulk density of an aggregate does not depend upon
a) size and shape of aggregates
b) specific gravity of aggregates
c) grading of aggregates
d) size and shape of the container
80. Workability of concrete for a given water content is good if aggregates used are
a) rounded aggregate
b) irregular aggregate
c) angular aggregate
d) flaky aggregate
81. The aggregate impact value of the aggregate used in
a) building concrete is less than 45
b) road pavement concrete is less than 30
c) runway concrete is less than 30
d) all of the above
82. The void ratio of
a) single size coarse aggregate is roughly 0.45
b) graded coarse aggregate is roughly 0.40
c) fine aggregate is roughly 0.45
d) all of the above
83. The aggregate containing moisture in pores and having its
surface dry, is known as
a) moist aggregates
b) very dry aggregates
c) dry aggregates
d) saturated surface dry aggregates
84. Pick up the correct statement from the following:
a) bulking of sand is caused due to formation of a thin film of surface moisture
b) fine sand bulks more than coarse sand
c) with 10% moisture content by weight, the bulking of sand is increased by 50%
d) the volume of fully saturated sand, is equal to the volume of dry and loose sand
e) all of the above
85. Log Angles machine is used to test the aggregate for
a) crushing strength
b) impact value
c) abrasion resistance
d) water absorption
86. Pick up the correct statement from the following:
a) the bulk density of fine aggregate is usually about 10 percent more than that of coarse aggregate of similar composition
b) the specific gravity of aggregate is important for the determination of the moisture content
c) the absorption and porosity of an aggregate, influence the property of the concrete
d) a highly absorptive aggregate reduces the workability of concrete considerably
e) all of the above
87. If 20 kg of a coarse aggregate is sieved through 80mm, 40 mm, 20 mm, 10 mm, 4.75 mm, 2.36 mm, 1.18 mm, 600 micron, 300 micron and 150 micron standard sieves and the weights retained are 0 kg, 2 kg, 5 kg, 6 kg, 4 kg, 3kg respectively, the fineness modulus of the aggregate, is
a) 7.30
b) 7.35
c) 7.40
d) 7.45
88. The percentage of the aggregate of F.M. 2.6 to be combined with coarse aggregate of F.M. 6.8 for obtaining the aggregates
F.M 5.4 in
a) 30%
b) 40%
c) 50%
d) 60%
89. IS sieve No. 10 mm and 4.75 mm are generally used for grading of
a) coarse aggregate
b) fine aggregate
c) neither (a) nor (b)
d) both (a) and (b) of above
90. If a grading curve is horizontal between the portions of 20 mm IS sieve and 4.75 mm IS sieve, graded aggregates do not contain.
a) 20 mm particles
b) 10 mm particles
c) 4.75 mm particles
d) all of the above
91. For the construction of cement concrete dams, the maximum permissible size of the aggregates, is
a) 40 mm
b) 50 mm
c) 60 mm
d) 70 mm
92. For the construction of cement concrete floor, the maximum permissible size of the aggregates, is
a) 4 mm
b) 6 mm
c) 8 mm
d) 10 mm
93.The most useless aggregates is one whose surface texture is
a) smooth
b) granular
c) glossy
d) honey combed and porous
94. The concrete mainly consists of a) cement
c) aggregate
b) sand
d) all of the above
95. The impurity of mixing water which affects the setting time and strength of concrete, is
a) sodium sulphates
b) sodium chlorides
c) sodium carbonates and bicarbonates
d) calcium chlorides
96. Water cement ratio is
a) volume of water to that of cement
b) weight of water to that of cement
c) weight of concrete to that of water
d) volume of concrete to that of water
e) both (a) and (b) of the above
97. Water cement ratio by weight is
a) higher as compared to that by volume.
b) lower as compared to volume
c) same as that by volume
d) none of the above
98. Water cement ratio is generally expressed in volume of water required per
a) 10 kg
b) 20 kg
c) 30 kg
d) 50 kg
99. Water cement ratio is normally used
a) 0.4-0.5
b) 0.5-0.6
c) 0.6-0.65
d) 0.05-0.70
100. How much water read for M₂0 mix concrete of cement 50kg?
a) 30 lit
b) 35 lit
c) 35 lit
d) 40 lit
