If the permissible stress in steel in tension is 140 N/mm², then the depth of neutral axis for a singly reinforced rectangular balanced section will be
0.35 d
0.40 d
0.45 d
Dependent on grade of concrete also
Correct Answer :
B. 0.40 d
Related Questions
Pick up the correct statement from the following:
Construction joints in columns are provided a few cm below the junction of beam
Construction joints in columns are provided at the bottom hunching
Construction joints in beams and slabs are provided within middle third
All the above
Curing
Reduces the shrinkage of concrete
Preserves the properties of concrete
Prevents the loss of water by evaporation
All of the above
For ensuring quality of concrete, use
Single sized aggregates
Two sized aggregate
Graded aggregates
Coarse aggregates
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
The shuttering of a hall measuring 4 m × 5 m, can be removed after
5 days
7 days
10 days
14 days
For an ordinary Portland cement
Residual does not exceed 10% when sieved through IS Sieve No. 9
Soundness varies from 5 to 10 mm
Initial setting time is not less than 30 minutes
Compressive stress after 7 days, is not less than 175 kg/cm2
Permissible compressive strength of M 200 concrete grade is
100 kg/cm2
150 kg/cm2
200 kg/cm2
250 kg/cm2
The compaction of concrete, improves
Density
Strength
Durability
All the above
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
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
For construction of structures in sea water, the cement generally preferred to, is
Portland-pozzolana cement
Quick setting cement
Low heat Portland cement
Rapid hardening cement
As compared to ordinary Portland cement, use of pozzolana cement
Reduces workability
Increases bleeding
Increases shrinkage
Increases strength
The strength and quality of concrete, depend upon:
Grading of aggregates
Surface area of aggregates
Shape of aggregates
All the above
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 %
Log Angles machine is used to test the aggregate for
Crushing strength
Impact value
Abrasion resistance
Water absorption
The specifications of a cement bag for storage, are
Weight 50 kg
Height 18 cm
Plan area 3000 sq. cm
All the above
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
In the method of voids for determination of the quantity of cement paste, it is assumed that
Voids in coarse aggregates are filled by fine aggregates
Voids in fine aggregates are filled by the cement paste
Volume of fine aggregates is equal to total voids in coarse aggregates plus 10% extra
All the above
The ratio of the diameter of reinforcing bars and the slab thickness is
1/4
1/5
1/6
1/8
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
Efflorescence in cement is caused due to an excess of
Alumina
Iron oxide
Silica
Alkalis
Concrete is unsuitable for compaction by a vibrator if it is
Dry
Earth moist
Semi-plastic
Plastic
A continuous beam is deemed to be a deep beam when the ratio of effective span to overall depth (1/D) is less than
1.5
2.0
2.5
3.0
Half of the main steel in a simply supported slab is bent up near the support at a distance of x from the center of slab bearing where x is equal to (Where l is the span)
l/3
l/5
l/7
l/10
In T-shaped R C. retaining walls, the main reinforcement in the stem is provided on
The front face in one direction
The front face in both directions
The inner face in one direction
The inner face in both directions
Vicat's apparatus is used for
Fineness test
Consistency test
Setting time test
Soundness test
The minimum percentage of chemical ingredient of cement is that of
Magnesium oxide
Iron oxide
Alumina
Lime
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
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
Addition of pozzolana to cement
Decreases workability
Increases strength
Increases heat of hydration
None of these