The risk of segregation is more for
Wetter mix
Larger proportion of maximum size aggregate
Coarser grading
All the above
Correct Answer :
D. All the above
Related Questions
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
All the above
For the construction of R.C.C. slabs, columns, beams, walls, etc. the grade of concrete mix used, is
1 : 3 : 6
1 : 1 ½ : 3
1 : 2 : 4
1 : 1 : 2
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
90 minutes
1% of voids in a concrete mix would reduce its strength by about
5 %
10 %
15 %
20 %
Percentage of pozzolanic material containing clay upto 80% used for the manufacture of pozzolana cement, is
30 %
40 %
50 %
60 %
The entrained air in concrete
Increases workability
Decreases workability
Decreases resistance to weathering
Increases strength
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
Shrinkage in concrete can be reduced by using
Low water cement ratio
Less cement in the concrete
Proper concrete mix
All the above
In reinforced concrete footing on soil, the minimum thickness at edge should not be less than
100 mm
150 mm
200 mm
250 mm
The type of aggregates of same nominal size, which contain less voids when compacted, are
Rounded spherical
Irregular
Flaky
None of these
An ideal ware house, is provided
Water proof masonry walls
Water proof roof
Few windows which remain generally closed
All the above
The light weight aggregates are obtained from
Sedimentary rocks
Metamorphic rocks
Igneous rocks
Volcanic source
'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
Pick up the incorrect statement from the following:
The degree of grinding of cement, is called fineness
The process of changing cement paste into hard mass, is known as setting of cement
The phenomenon by virtue of which cement does not allow transmission of sound, is known as soundness of cement
The heat generated during chemical reaction of cement with water, is known as heat of hydration
The cement becomes useless if its absorbed moisture content exceeds
1 %
2 %
3 %
5 %
The mixture of different ingredients of cement, is burnt at
1000°C
1200°C
1400°C
1600°C
If the depth of moist sand in a cylinder is 15 cm and the depth of the sand when fully inundated with water is 12 cm, the bulking of the moist sand, is
10 %
12 %
15 %
25 %
Approximate value of shrinkage strain in concrete, is
0.003
0.0003
0.00003
0.03
After casting, an ordinary cement concrete on drying
Expands
Mix
Shrinks
None of these
Minimum grade of concrete to be used in reinforced concrete as per IS: 4561978 is
M 15
M 20
M 10
M 25
If a beam fails in bond, then its bond strength can be increased most economically by
Increasing the depth of beam
Using thinner bars but more in number
Using thicker bars but less in number
Providing vertical stirrups
Concrete gains strength due to
Chemical reaction of cement with sand and coarse aggregates
Evaporation of water from concrete
Hydration of cement
All the above
According to ISI recommendations, the maximum depth of stress block for balanced section of a beam of effective depth d is
0.43 d
0.55 d
0.68 d
0.85 d
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
Strength of concrete with passage of time
Increases
Decreases
Fluctuates
Remains constant
High temperature
Increases the strength of concrete
Decreases the strength of concrete
Has no effect on the strength of concrete
None of these
Addition of pozzolana to cement causes
Reduction in permeability
Loss of heat of hydration
Reduction in bleeding
All the above
To minimise the effect of differential settlement, the area of a footing should be designed for
Dead load only
Dead load + live load
Dead load + fraction of live load
Live load + fraction of dead load
Separation of water or water sand cement from a freshly concrete, is known
Bleeding
Creeping
Segregation
Flooding
Most common method of pre-stressing used for factory production is
Long line method
Freyssinet system
Magnel-Blaton system
Lee-Macall system