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
Correct Answer :
D. All the above
Related Questions
If the storey height is equal to length of RCC wall, the percentage increase in strength is
0
10
20
30
For concreting tunnel linings, transportation of concrete is done by
Pans
Wheel borrows
Containers
Pumps
Pick up the incorrect statement from the following:
The bottom and top ends of slump mould are parallel to each other
The axis of the mould is perpendicular to the end faces
The internal surface of the mould is kept clean and free from set cement
The mould is in the form of a frustum of hexagonal pyramid
Percentage of pozzolanic material containing clay upto 80% used for the manufacture of pozzolana cement, is
30 %
40 %
50 %
60 %
Sand generally contains salt if it is obtained from:
Nala beds
River beds
Sea beds
None of these
How long will it take for the concrete to achieve 100% of its strength?
7 days
14 days
21 days
28 days
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)
For the design of retaining walls, the minimum factor of safety against overturning is taken as
1.5
2.0
2.5
3.0
Separation of coarse aggregates from mortar during transportation, is known
Bleeding
Creeping
Segregation
Shrinkage
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
Pick up the incorrect statement from the following:
Tricalcium silicate (C3S) hydrates rapidly
Tricalcium silicate (C3S) generates more heat of hydration
Tricalcium silicate (C3S) develops early strength
Tricalcium silicate (C3S) has more resistance to sulphate attack
The ratio of the diameter of reinforcing bars and the slab thickness is
1/4
1/5
1/6
1/8
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 batching 1:3:6 concrete mix by volume, the ingredients required per bag of 50 kg cement, are:
70 litres of sand and 120 litres of aggregates
70 kg of sand and 140 litres of aggregates
105 litres of sand and 140 litres of aggregates
105 litres of sand and 210 litres of aggregates
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
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
Water cement ratio is
Volume of water to that of cement
Weight of water to that of cement
Weight of concrete to that of water
Both (a) and (b) of the above
The cement becomes useless if its absorbed moisture content exceeds
1 %
2 %
3 %
5 %
The property of the ingredients to separate from each other while placing the concrete is called
Segregation
Compaction
Shrinkage
Bulking
Permissible compressive strength of M 200 concrete grade is
100 kg/cm2
150 kg/cm2
200 kg/cm2
250 kg/cm2
For ensuring quality of concrete, use
Single sized aggregates
Two sized aggregate
Graded aggregates
Coarse aggregates
In pre-stressed concrete
Forces of tension and compression change but lever arm remains unchanged
Forces of tension and compressions remain unchanged but lever arm changes with the moment
Both forces of tension and compression as well as lever arm change
Both forces of tension and compression as well as lever arm remain unchanged
The percentage of voids in cement is approximately
25 %
40 %
60 %
80 %
The factor which affects workability, is
Water content and its temperature
Shape and size of the aggregates
Air entraining agents
All the above
The main reinforcement in the heel of a T-shaped R.C. retaining wall is provided on
Top face perpendicular to wall
Bottom face perpendicular to wall
Both top and bottom faces perpendicular to wall
None of the above
The high strength of rapid hardening cement at early stage, is due to its
Finer grinding
Burning at high temperature
Increased lime cement
Higher content of tricalcium
Ordinary concrete is not used for concrete grade
M 100
M 150
M 250
M 400
Assertion A : The load factor for live load is greater than that for dead load. Reason R : The live loads are more uncertain than dead loads. Select your answer based on the coding system given below:
Both A and R is true and R is the correct explanation of A
Both A and R is true but R is not the correct explanation of A
A is true but R is false
A is false but R is true
Workability improved by adding
Fly ash
Hydrated lime
Calcium chloride
All the above
Pozzolana cement is used with confidence for construction of
Dams
Massive foundations
R.C.C. structures
All the above