For the construction of cement concrete dams, the maximum permissible size of the aggregates, is
40 mm
50 mm
60 mm
70 mm
Correct Answer :
A. 40 mm
Related Questions
Pick up the correct statement from the following:
The weight of ingredients of concrete mix, is taken in kilograms
Water and aggregates are measured in litres
20 bags of cement make one tonne
All the above
The minimum cover in a slab should neither be less than the diameter of bar nor less than
10 mm
15 mm
25 mm
13 mm
Non-uniform compaction may cause the concrete
Porous
Non-homogeneous
Reduced strength
All the above
According to IS : 382-1963, a good aggregate should be
Chemically inert
Sufficiently strong
Hard and durable
All the above
Pick up the correct statement from the following:
A highly absorptive aggregate reduces the workability of concrete considerably
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
All the above
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 bulk density of aggregates, is generally expressed as
Tonnes/cubic metre
kg/cubic metre
kg/litre
g/cm3
Separation of coarse aggregates from mortar during transportation, is known
Bleeding
Creeping
Segregation
Shrinkage
Shrinkage in concrete can be reduced by using
Low water cement ratio
Less cement in the concrete
Proper concrete mix
All the above
Tricalcium aluminate (C3A)
Reacts fast with water
Generates less heat of hydration
Causes initial setting and early strength of cement
Does not contribute to develop ultimate strength
The fineness modulus of fine aggregate is in the range of
2.0 to 3.5
3.5 to 5.0
5.0 to 7.0
6.0 to 8.5
If the engineer-in-charge approves, the 10 cm cubes may be used for the work test of concrete provided maximum nominal size of aggregate, does not exceed
10 cm
15 cm
20 cm
25 cm
Log Angles machine is used to test the aggregate for
Crushing strength
Impact value
Abrasion resistance
Water absorption
Pick up the correct statement from the following:
The quality of water governs the strength of concrete
10% excess of water reduces the strength of concrete by 15%
30% excess of water reduces the strength of concrete by 50%
All the above
Critical section for shear in case of flat slabs is at a distance of
Effective depth of slab from periphery of column/drop panel
d/2 from periphery of column/capital/ drop panel
At the drop panel of slab
At the periphery of column
Addition of pozzolana to cement
Decreases workability
Increases strength
Increases heat of hydration
None of these
The commercial name of white and coloured cement in India, is
Colorcrete
Silvicrete
Snowcem
All the above
The produce impermeable concrete
Thorough mixing of concrete is required
Proper compaction of concrete is required
Proper curing of concrete is required
All the above
Pick up the incorrect statement from the following:
A rich mix of concrete possesses higher strength than that a lean mix of desired workability with excessive quantity of water
The strength of concrete decreases as the water cement ratio increases
Good compaction by mechanical vibrations, increases the strength of concrete
None of these
Permissible compressive strength of M 200 concrete grade is
100 kg/cm2
150 kg/cm2
200 kg/cm2
250 kg/cm2
The strength of concrete after one year as compared to 28 days strength is about
10 to 15% more
15 to 20% more
20 to 25% more
25 to 50% more
In symmetrically reinforced sections, shrinkage stresses in concrete and steel are respectively
Compressive and tensile
Tensile and compressive
Both compressive
Both tensile
In the design of a front counterfort in a counterfort retaining wall, the main reinforcement is provided on (i) Bottom face near counterfort (ii) Top face near counterfort (iii) Bottom face near centre of span (iv) Top face near centre of span The correct answer is
Only (i)
Only (ii)
Both (i) and (iv)
Both (ii) and (iii)
Internal friction between the ingredients of concrete, is decreased by using
Less water
Fine aggregates
Rich mix
More water and coarse aggregates
The final operation of finishing floors, is known as
Screeding
Floating
Trowelling
Finishing
Water cement ratio is
Volume of water to that of cement
Weight of water to that of cement
Weight of concrete to that of water
Both (a) and (b) of the above
Pick up the correct proportions of chemical ingredients of cement
Lime : Silica : Alumina : Iron oxide : 63 : 22 : 6 : 3
Silica : Lime : Alumina : Iron oxide : 63 : 22 : 6 : 3
Alumina : Silica : Lime : Iron oxide : 63 : 22 : 6 : 3
Iron oxide : Alumina : Silica : Lime : 63 : 22 : 6 : 3
Poisson's ratio for concrete
Remains constant
Increases with richer mixes
Decreases with richer mixes
None of the above
Workability of concrete is directly proportional to
Aggregate cement ratio
Time of transit
Grading of the aggregate
All of above
Pick up the correct statement from the following:
Water enables chemical reaction to take place with cement
Water lubricates the mixture of gravel, sand and cement
Strength of concrete structure largely depends upon its workability
All the above