Q.1

In slump test, each layer of concrete is compacted by a steel rodcm long and ofmm diameter for

  • 20 times
  • 25 times
  • 30 times
  • 40 times
  • 50 times
Q.2

If P, Y and Z are the weights of cement, fine aggregates and coarse aggregates respetively and W/C is the water cement ratio, the minimum quantity of water to be added to first batch, is obtained by the equation

  • 0.1P + 0.3Y + 0.1Z = W/C x P
  • 0.3P + 0.1Y + 0.01Z = W/C x P
  • 0.4P + 0.2Y + 0.01Z = W/C x P
  • 0.5P + 0.3Y + 0.01Z = W/C x P
  • 0.2P + 0.5Y + 0.1Z = W/C x P
Q.3

To prevent segregation, the maximum height for placing concrete, is

  • 100 cm
  • 125 cm
  • 150 cm
  • 200 cm
  • 250 cm
Q.4

The process of mixing, transporting, placing and compacting concrete using Ordinary Port land Cement should not take more than

  • 30 minutes
  • 40 minutes
  • 60 minutes
  • 75 minutes
  • 90 minutes.
Q.5

A construction joint is provided where

  • bending moment is small
  • shear force is small
  • the member is supported by other member
  • all the above.
Q.6

An aggregate is known as cyclopean aggregate if its size is more than

  • 4.75 mm
  • 30 mm
  • 60 mm
  • 75 mm
  • 90 mm.
Q.7

Strength of concrete with passage of time

  • increases
  • decreases
  • fluctuates
  • remains constant.
Q.8

For given workability the grading requiring the least amount of water is one that gives

  • greatest surface area for the given cement and aggregates
  • least surface area for the given cement and aggregates
  • least weight for the given cement and aggregates
  • greatest weight for the given cement and aggregates
  • none of these.
Q.9

Le-Chatelier's apparatus is used for testing

  • soundness of cement
  • hardness of cement
  • strength of cement
  • durability of cement.
Q.10

Curing of pavements, floors, roofs and slabs, is done by

  • membrane method
  • ponding method
  • covering surface with bags
  • sprinkling water method
  • shading concrete method.
Q.11

Sand generally contains salt if it is obtained from:

  • nala beds
  • river beds
  • sea beds
  • all the above
  • none of these.
Q.12

Pick up the correct statement from the following:

  • The bulk density of fine aggregate is usually about 10 per cent more than that of coarse aggregate of similar composition
  • The specific gravity of aggregate is important for the determination of the moisture content
  • The absorption and porosity of an aggregate influence the property of the concrete
  • A highly absorptive aggregate reduces the workability of concrete considerably
  • All the above.
Q.13

Placing of concrete should preferably be done at a temperature of

  • 0°C
  • 10°C
  • 20°C
  • 23°C
  • 27 ± 2°C
Q.14

Setting time of cement increases by adding

  • gypsum
  • hydrogen peroxide
  • calcium chloride
  • sodium oxide
  • none of these.
Q.15

For concreting tunnel linings, tran-portation of concrete is done by

  • pans
  • wheel borrows
  • containers
  • pumps
  • belt conveyors.
Q.16

The entrained air in concrete

  • increases workability
  • decreases workability
  • decreases resistance to weathering
  • increases strength
  • neither affects workability nor strength.
Q.17

Workability improved by adding

  • fly ash
  • hydrated lime
  • calcium chloride
  • bentonite
  • all the above.
Q.18

If the average compressive strength iskg/cm2 and standard deviation isthe co-efficient of variation is

  • 10%
  • 12.5%
  • 15%
  • 18.5 %
  • 20%
Q.19

For the construction of thin R.C.C. structures, the type of cement to be avoided, is

  • ordinary Portland cement
  • rapid hardening cement
  • low heat cement
  • blast furnace slag cement
  • sulphate resisting cement.
Q.20

If the various concrete ingredients i.e. cement, sand and aggregates are in the ratio of 1:3:the grade of concrete, is

  • M 100
  • M 150
  • M 200
  • M 250
  • M 300
Q.21

Pick up the incorrect statement from the following. While performing preliminary test on concrete

  • proportions of the material and water should be the same as to be used at the work site
  • cement should be mixed by hand in order to maintain uniformity
  • concrete mix should be stored in air-tight containers
  • concrete ingredients should be kept at a temperature of 37° ± 2°C
  • none of these.
Q.22

The main object of compaction of concrete, is:

  • to eliminate air holes
  • to achieve maximum density
  • to provide initimate contact between the concrete and embedded materials
  • all the above.
Q.23

The minimum percentage of chemical ingredient of cement is that of

  • magnesium oxide
  • iron oxide
  • alumina
  • lime
  • silica.
Q.24

'Ware house pack' of cement means

  • full capacity of the ware house
  • pressure exertion of the bags of upper layers
  • pressure compaction of the bags on lower layers
  • packing the ware house
  • none of these.
Q.25

Pick up the incorrect statement from the following:

  • With passage of time, the strength of cement increases
  • With passage of time, the strength of cement decreases
  • After a period of 24 months, the strength of cement reduces to 50%
  • The concrete made with storage deteriorated cement, gains strength with time
  • None of these.
Q.26

The impurity of mixing water which affects the setting time and strength of concrete, is

  • sodium sulphates
  • sodium chlorides
  • sodium carbonates and bicarbonates
  • calcium chorides
  • calcium bicarbonates
Q.27

Horizontal construction joints in concrete walls are generally provided at

  • soffit level
  • window sill level
  • floor level
  • all the above.
Q.28

The aggregate impact value of the aggregate used in

  • building concrete is less than 45
  • road pavement concrete is less than 30
  • runway concrete is less than 30
  • all the above.
Q.29

The operation of removing humps and hollows of uniform concrete surface, is known as

  • floating
  • screeding
  • trowelling
  • finishing
  • none of these.
Q.30

If the slump of a concrete mix ismm, its workability is

  • very low
  • low
  • medium
  • high
  • none of these.
0 h : 0 m : 1 s