In reinforced concrete footing on soil, the minimum thickness at edge should not be less than
100 mm
150 mm
200 mm
250 mm
Correct Answer :
B. 150 mm
Related Questions
If the various concrete ingredients i.e. cement, sand and aggregates are in the ratio of 1:3:6, the grade of concrete, is
M 100
M 150
M 200
M 250
Normally pre-stressing wires are arranged in the
Upper part of the beam
Lower part of the beam
Center
Anywhere
Select the correct statement
Elastic modulus of high tensile steel is nearly the same as that of mild steel
Elastic modulus of high tensile steel is more than that of mild steel
Carbon percentage in high carbon steel is less than that in mild steel
High tensile steel is cheaper than mild steel
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
The most commonly used admixture which prolongs the setting and hardening time is
Gypsum
Calcium chloride
Sodium silicate
All of the above
I.S. Sieve Nos. 10 mm and 4.75 mm are generally used for grading of
Coarse aggregates
Fine aggregates
Neither (a) nor (b)
Both (a) and (b)
The compaction of concrete, improves
Density
Strength
Durability
All the above
Workability of concrete mix with low water cement ratio is determined by
Tensile strength test
Slump test
Compaction factor test
Flexural strength test
According to the recommendations of IS : 456-1978, the expansion joints
Are provided where plane changes abruptly
Are provided to ensure minimum resistance
Do not carry reinforcement across them
All the above
Construction joints are generally provided in concrete
Roads
Retaining walls
Lining of canals
All the above
For given water content, workability decreases if the concrete aggregates contain an excess of
Thin particles
Flat particles
Elongated particles
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
Permissible compressive strength of M 200 concrete grade is
100 kg/cm2
150 kg/cm2
200 kg/cm2
250 kg/cm2
Efflorescence in cement is caused due to an excess of
Alumina
Iron oxide
Silica
Alkalis
An ordinary Portland cement when tested for its fineness, should not leave any residue on I.S. sieve No. 9, more than
5 %
10 %
15 %
20 %
Pick up the correct statement from the following:
An increase in water content must be accompanied by an increase in cement content
Angular and rough aggregates reduce the workability of the concrete
The slump of the concrete mix decreases due to an increase in temperature
All the above
Finer grinding of cement
Affects only the early development of strength
Affects only the ultimate strength
Both (A) and (B)
Does not affect the strength
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
For a continuous slab of 3 m × 3.5 m size, the minimum overall depth of slab to satisfy vertical deflection limits is
50 mm
75 mm
100 mm
120 mm
The diameter of ties in a column should be
More than or equal to one fourth of diameter of main bar
More than or equal to 5 mm
More than 5 mm but less than one-fourth of diameter of main bar
More than 5 mm and also more than one-fourth of diameter of main bar
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
Air entrainment in the concrete increases
Workability
Strength
The effects of temperature variations
The unit weight
Pick up the correct statement from the following:
Higher workability indicates unexpected increase in the moisture content
Higher workability indicates deficiency of sand
If the concrete mix is dry, the slump is zero
All the above
Ordinary Portland cement is manufactured from
Lime stone and clay
Gypsum and lime
Pozzolana
Lime, pozzolana and clay
The average permissible stress in bond for plain bars in tension is
Increased by 10% for bars in compression
Increased by 25% for bars in compression
Decreased by 10% for bars in compression
Decreased by 25% for bars in compression
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 is unsuitable for compaction by a vibrator if it is
Dry
Earth moist
Semi-plastic
Plastic
Joints in concrete structures, are provided
To reduce the tensile stresses likely to be developed due to evaporation of water
To minimise the change in the dimensions of the slab
To minimise the necessary cracking
All the above
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 a good concrete
Aggregates should be hard and durable
Water should be free from organic materials
Cement should be sufficient to produce the required strength
All the above