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
Correct Answer :
D. All the above
Related Questions
Workability improved by adding
Air-entraining agent
Foaming agent
Oily-agent
All the above
A concrete having a slump of 6.5 cm, is said to be
Dry
Earth moist
Semi-plastic
Plastic
The strength and quality of concrete, depend upon:
Grading of aggregates
Surface area of aggregates
Shape of aggregates
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
In a pile of length l, the points of suspension from ends for lifting it are located at
0.207 l
0.25 l
0.293 l
0.333 l
Ratio of permissible stress in direct compression and bending compression is
Less than 1
Between 1 and 1.5
Between 1.5 and 2.0
Greater than 2
In a spherical dome the hoop stress due to a concentrated load at crown is
Compressive everywhere
Tensile everywhere
Partly compressive and partly tensile
Zero
Construction joints are generally provided in concrete
Roads
Retaining walls
Lining of canals
All the above
The size of fine aggregates does not exceed
2.75 mm
3.00 mm
3.75 mm
4.75 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 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
Maximum quantity of water needed per 50 kg of cement for M 15 grade of concrete is
28 liters
30 liters
32 liters
34 liters
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
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
The compressive strength of 100 mm cube as compared to 150 mm cube is always
Less
More
Equal
None of the above
Approximate value of shrinkage strain in concrete, is
0.003
0.0003
0.00003
0.03
The individual variation between test strength of sample should not be more than
± 5 % of average
± 10 % of average
± 15 % of average
± 20 % of average
Hydration of cement is due to chemical action of water with
Tricalcium silicate and dicalcium silicate
Dicalcium silicate and tricalcium aluminate
Tricalcium aluminate and tricalcium alumino ferrite
All the 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
The commonly used material in the manufacture of cement is
Sand stone
Slate
Lime stone
Graphite
The approximate value of the ratio between direct tensile strength and flexural strength is
0.33
0.5
0.75
1.0
Batching error means inaccuracy in the quantity of
Aggregates
Cement
Water
All the above
Sinking of an intermediate support of a continuous beam (i) Reduces the negative moment at support (ii) Increases the negative moment at support (iii) Reduces the positive moment at center of span (iv) Increases the positive moment at center of span The correct answer is
(i) and (iii)
(i) and (iv)
(ii) and (iii)
(ii) and (iv)
Slump test of concrete is a measure of its
Consistency
Compressive strength
Tensile strength
Impact value
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 critical section for finding maximum bending moment for footing under masonry wall is located
At the middle of the wall
At the edge of the wall
Halfway between the middle and edge of the wall
At a distance equal to effective depth of footing from the edge of the wall
Pick up the incorrect statement from the following:
Concrete for which preliminary tests are conducted, is called controlled concrete
Bulking of sand depends upon the fineness of grains
Concrete mix 1 : 6 : 12, is used for mass concrete in piers
All the above
The percentage of reinforcement in case of slabs, when high strength deformed bars are used is not less than
0.15
0.12
0.30
1.00
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
Permissible compressive strength of M 200 concrete grade is
100 kg/cm2
150 kg/cm2
200 kg/cm2
250 kg/cm2