In slump test, each layer of concrete is compacted by a steel rod 60 cm long and of 16 mm diameter for
20 times
25 times
30 times
50 times
Correct Answer :
B. 25 times
Related Questions
Vicat's apparatus is used for
Fineness test
Consistency test
Setting time test
Soundness test
High carbon content in the steel causes
Decrease in tensile strength but increase in ductility
Increase in tensile strength but decrease in ductility
Decrease in both tensile strength and ductility
Increase in both tensile strength and ductility
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 aggregates completely pass through a sieve of size 75 mm and are retained on a sieve of size 60 mm, the particular aggregate will be flaky if its minimum dimension is less than
20.5 mm
30.5 mm
40.5 mm
50.5 mm
Expansion joints are provided if the length of concrete structures exceeds
10 m
15 m
15 m
45 m
The light weight aggregates are obtained from
Sedimentary rocks
Metamorphic rocks
Igneous rocks
Volcanic source
The process of proper and accurate measurement of concrete ingredients for uniformity of proportion, is known
Grading
Curing
Mixing
Batching
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
A higher modular ratio shows
Higher compressive strength of concrete
Lower compressive strength of concrete
Higher tensile strength of steel
Lower tensile strength of steel
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
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
For a slab supported on its four edges with corners held down and loaded uniformly, the Marcus correction factor to the moments obtained by Grashoff Rankine's theory
Is always less than 1
Is always greater than 1
Can be more than 1
Can be less than 1
Poisson's ratio for concrete
Remains constant
Increases with richer mixes
Decreases with richer mixes
None of the above
To determine the modulus of rupture, the size of test specimen used is
150 × 150 × 500 mm
100 × 100 × 700 mm
150 × 150 × 700 mm
100 × 100 × 500 mm
In reinforced concrete footing on soil, the minimum thickness at edge should not be less than
100 mm
150 mm
200 mm
250 mm
Setting time of cement increases by adding
Gypsum
Hydrogen peroxide
Calcium chloride
Sodium oxide
For a longitudinal reinforcing bar in a column, the minimum cover shall neither be less than the diameter of bar nor less than
15 mm
25 mm
30 mm
40 mm
The maximum percentage of chemical ingredient of cement is that of
Magnesium oxide
Iron oxide
Silica
Lime
Pick up the correct statement from the following:
Construction joints are necessarily planned for their locations
Expansion joints are provided to accommodate thermal expansion
Construction joints are provided to control shrinkage cracks
All the above
The concrete mix which causes difficulty in obtaining a smooth finish, possess
Segregation
Internal friction
Hardness
Bleeding
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
Slump test of concrete is a measure of its
Consistency
Compressive strength
Tensile strength
Impact value
Workability improved by adding
Air-entraining agent
Foaming agent
Oily-agent
All the above
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
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
The minimum cover to the ties or spirals should not be less than
15 mm
20 mm
25 mm
50 mm
The diameter of the Vicat plunger is 10 mm and its length varies from
20 mm to 30 mm
30 mm to 40 mm
40 mm to 50 mm
50 mm to 60 mm
Diagonal tension in a beam
Is maximum at neutral axis
Decreases below the neutral axis and increases above the neutral axis
Increases below the neutral axis and decreases above the neutral axis
Remains same
If 50 kg of fine aggregates and 100 kg of coarse aggregates are mixed in a concrete whose water cement ratio is 0.6, the weight of water required for harsh mix, is
8 kg
10 kg
12 kg
14 kg
The operation of removing humps and hollows of uniform concrete surface, is known as
Floating
Screeding
Trowelling
Finishing