Shrinkage of concrete depends upon
(i) Humidity of atmosphere
(ii) Passage of time
(iii) Stress The correct answer is
(i) and (ii)
(ii) and (iii)
Only (iii)
All (i), (ii) and (iii)
Correct Answer :
A. (i) and (ii)
Related Questions
Batching error means inaccuracy in the quantity of
Aggregates
Cement
Water
All the above
In a spherical dome the hoop stress due to a concentrated load at crown is
Compressive everywhere
Tensile everywhere
Partly compressive and partly tensile
Zero
The approximate value of the ratio between direct tensile strength and flexural strength is
0.33
0.5
0.75
1.0
Pick up the correct statement from the following:
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
Minimum pitch of transverse reinforcement in a column is
The least lateral dimension of the member
Sixteen times the smallest diameter of longitudinal reinforcement bar to be tied
Forty-eight times the diameter of transverse reinforcement
Lesser of the above three values
Concrete containing
Siliceous aggregates, has higher co-efficient of expansion
Igneous aggregates, has intermediate coefficient of expansion
Lime stones, has lowest co-efficient of expansion
All the above
Stress strain curve of high tensile steel
Has a definite yield point
Does not show definite yield point but yield point is defined by 0.1% proof stress
Does not show definite yield point but yield point is defined by 0.2% proof stress
Does not show definite yield point but yield point is defined by 2% proof stress,
On a grading curve, the gap grading is represented by
A horizontal line
A vertical line
N.W. inclined line
N.E. inclined line
The maximum percentage of chemical ingredient of cement is that of
Magnesium oxide
Iron oxide
Silica
Lime
The type of aggregates of same nominal size, which contain less voids when compacted, are
Rounded spherical
Irregular
Flaky
None of these
The ratio of the length to breadth of a wooden float, is
4.5
5.5
6.5
7.5
The main reinforcement in the toe of a T-shaped R C. retaining wall is provided on
(i) Top face parallel to the wall
(ii) Top face perpendicular to the wall
(iii) Bottom face parallel to the wall
(iv) Bottom face perpendicular to the wall The correct answer is
Only (ii) is correct
(i) and (ii) are correct
(iii) and (iv) are correct
Only (iv) is correct
Proper batching ensures
Economy
Durability
Workability
All the above
Construction joints are generally provided in concrete
Roads
Retaining walls
Lining of canals
All the above
M 150 grade of concrete approximates
1 : 3 : 6 mix
1 : 1 :2 mix
1 : 2 : 4 mix
1 : 1.5 : 3 mix
In working stress design, permissible bond stress in the case of deformed bars is more than that in plain bars by
10 %
20 %
30 %
40 %
The entrained air in concrete
Increases workability
Decreases workability
Decreases resistance to weathering
Increases strength
Specified compressive strength of concrete is obtained from cube tests at the end of
3 days
7 days
21 days
28 days
An aggregate which passes through 25 mm I.S. sieve and is retained on 20 mm sieve, is said to be flaky if its least dimension is less than
22.5 mm
18.5 mm
16.5 mm
13.5 mm
An ideal ware house, is provided
Water proof masonry walls
Water proof roof
Few windows which remain generally closed
All the above
Curing a concrete for long period ensures better
Volume stability
Strength
Water resistance
All the above
Ultimate strength of cold drawn high steel wires
Increases with increase in diameter of bar
Decreases with increase in diameter of bar
Does not depend on diameter of bar
None of the above
For batching 1:3:6 concrete mix by volume, the ingredients required per bag of 50 kg cement, are:
70 litres of sand and 120 litres of aggregates
70 kg of sand and 140 litres of aggregates
105 litres of sand and 140 litres of aggregates
105 litres of sand and 210 litres of aggregates
Pick up the correct statement from the following:
High percentage of C3S and low percentage of C2S cause rapid hardening
High percentage of C3S and low percentage of C2S make the cement less resistive to chemical attack
Low percentage of C3S and high percentage of C2S contribute to slow hardening
All the above
The increased cohesiveness of concrete, makes it
Less liable to segregation
More liable to segregation
More liable to bleeding
More liable for surface scaling in frosty weather
For a reinforced concrete section, the shape of shear stress diagram is
Wholly parabolic
Wholly rectangular
Parabolic above neutral axis and rectangular below neutral axis
Rectangular above neutral axis and parabolic below neutral axis
Pick up the correct statement from the following:
Sand stones may be divided into calcareous, siliceous and ferruginous sand stones
Concrete using sand stones, cracks due to excessive shrinkage
Broken bricks produce a concrete having good fire resisting qualities
All the above
For preparing ordinary concrete, the quantity of water used, is
5% by weight of aggregates plus 20% of weight of cement
10% by weight of aggregates plus 10% of weight of cement
5% by weight of aggregates plus 30% of weight of cement
30% by weight of aggregates plus 10% of weight of cement
For given water content, workability decreases if the concrete aggregates contain an excess of
Thin particles
Flat particles
Elongated particles
All the above
In a spherical dome subjected to concentrated load at crown or uniformly distributed load, the meridional force is always
Zero
Tensile
Compressive
Tensile or compressive