Q.1

According to IS : 382-a good aggregate should be

  • chemically inert
  • sufficiently strong
  • hard and durable
  • all the above.
Q.2

If the depth of moist sand in a cylinder iscm and the depth of the sand when fully inundated with water iscm, the bulking of the moist sand, is

  • 10%
  • 12%
  • 15%
  • 20%
  • 25%.
Q.3

Ordinary Portland cement is manufactured from

  • lime stone and clay
  • gypsum and lime
  • pozzolana
  • lime, pozzolana and clay.
Q.4

Pick up the correct statement from the following:

  • Sand obtained from pits, is washed to remove clay and silt
  • Sand obtained from flooded pits, need not be washed before use
  • Sea shore sand contains chlorides which cause effloresance
  • The chloride in sea shore sand and shingle may cause corrosion of reinforcement if the concrete is porous
  • All the above.
Q.5

For an ordinary Portland cement

  • residual does not exceed 10% when sieved through IS Sieve No. 9
  • soundness varies from 5 to 10 mm
  • initial setting time is not less than 30 minutes
  • compressive stress after 7 days, is not less than 175 kg/cm2
  • all the above.
Q.6

Gypsum is added for

  • colour
  • strength
  • controlling setting time
  • none of these.
Q.7

An excess of flaky particles in concrete aggregates

  • decreases the workability
  • increases the quantity of water and sand
  • affects the durability of concrete
  • more than 15% are not desirable
  • all the above.
Q.8

On a grading curve, the gap grading is represented by

  • a horizontal line
  • a vertical line
  • N.W. inclined line
  • N.E. inclined line
  • none of these.
Q.9

A concrete using an air entrained cement

  • has strength less than 10% to 15%
  • has more resistance to weathering
  • is more plastic and workable
  • is free from segregation and bleeding
  • all the above.
Q.10

Pick up the incorrect statement from the following:

  • Admixtures accelerate hydration
  • Admixtures make concrete water proof
  • Admixtures make concrete acid proof
  • Admixtures give high strength
  • None of these.
Q.11

Pick up the correct statement from the following:

  • There should not be any loss of cement from the charged drum of the mixer
  • Cement should be mixed for at least one minute
  • 10% of water is placed in the rotating drum before adding dry material
  • 10% of water is added after placing the other ingredients in the drum
  • All the above.
Q.12

An aggregate which passes throughmm I.S. sieve and is retained onmm sieve, is said to be flaky if its least dimension is less than

  • 22.5 mm
  • 18.5 mm
  • 16.5 mm
  • 15.5 mm
  • 13.5 mm.
Q.13

An ideal ware house, is provided

  • water proof masonry walls
  • water proof roof
  • few windows which remain generally closed
  • 15 cm thick concrete floor laid on a dry course of soling
  • all the above.
Q.14

Permissible compressive strength of Mconcrete grade is

  • 100 kg/cm2
  • 150 kg/cm2
  • 200 kg/cm2
  • 250 kg/cm2
  • 300 kg/cm2
Q.15

Thedays cube strength of mass concrete using aggregates of maximum size 5 cm for gravity dams should be

  • between 150 to 300 kg/cm2
  • between 350 to 600 kg/cm2
  • between 150 to 500 kg/cm2
  • below 200 kg/cm2
  • none of these.
Q.16

Pick up the correct statement from the following:

  • According to the petrological characteristics, concrete aggregates are classified as heavy weight, normal weight and light weight
  • According to the shape of the particles, concrete aggregates are classified as rounded irregular, angular and flaky
  • According to the surface texture of the particles, the concrete aggregates are classified as glassy, smooth, granular, rough, crystalline, honey combed and porous
  • All the above.
Q.17

A flaky aggregate is said to be elongated if its length is

  • equal to the mean size
  • twice the mean size
  • thrice the mean size
  • four times the mean size
  • five times the mean size.
Q.18

The strength and quality of concrete, depend upon:

  • grading of aggregates
  • surface area of aggregates
  • shape of aggregates
  • surface texture of aggregates
  • all the above.
Q.19

The maximum thickness of concrete floor of a cement warehouse, is

  • 10 cm
  • 15 cm
  • 20 cm
  • 25 cm
  • 30 cm
Q.20

The size of fine aggregates does not exceed

  • 5.75 mm
  • 2.75 mm
  • 3.00 mm
  • 3.75 mm
  • 4.75 mm
Q.21

A concrete having a slump of 6.5 cm, is said to be

  • dry
  • earth moist
  • semi-plastic
  • plastic
  • none of these.
Q.22

1.S.I. has specified the full strength of concrete after

  • 7 days
  • 14 days
  • 21 days
  • 28 days
  • 35 days
Q.23

The concrete mix which causes difficulty in obtaining a smooth finish, possess

  • segregation
  • internal friction
  • harshness
  • bleeding
  • none of these.
Q.24

Bulking of sand is

  • mixing of different sizes of sand particles
  • mixing of lime with sand
  • maximum water with sand
  • swelling of sand when wetted.
Q.25

Pick up the incorrect statement from the following:

  • Workability of the concrete mix decreases with an increase in the moisture content
  • Concrete for which preliminary tests are conducted, is called controlled concrete
  • Bulking of sand depends upon the fineness of grains
  • Concrete mix 1 : 6 : 12, is used for mass concrete in piers.
  • All the above.
Q.26

The bulk density of aggregates, depends upon

  • shape
  • grading
  • compaction
  • all the above.
Q.27

Pick up the correct statement from the following:

  • The maximum size of a coarse aggregate, is 75 mm and minimum 4.75 mm
  • The maximum size of the fine aggregate, is 4.75 mm and minimum 0.075 mm
  • The material having particles of size varying from 0.06 mm to 0.002 mm, is known as silt
  • The material having particles of size less than 0.002 mm, is known as clay
  • All the above.
Q.28

Higher workability of concrete is required if the structure is

  • made with cement concrete
  • thick and reinfored
  • thin and heavily reinforced
  • thick and heavily reinfored.
Q.29

Ifkg of fine aggregates andkg of coarse agregates are mixed in a concrete whose water cement ratio is 0.the weight of water required for harsh mix, is

  • 8 kg
  • 10 kg
  • 12 kg
  • 14 kg
  • 15 kg.
Q.30

Expansion joints are provided if the length of concrete structures exceeds

  • 10 m
  • 15 m
  • 15 m
  • 35 m
  • 45 m
0 h : 0 m : 1 s