Most common method of pre-stressing used for factory production is
Long line method
Freyssinet system
Magnel-Blaton system
Lee-Macall system
Correct Answer :
A. Long line method
Related Questions
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
Internal friction between the ingredients of concrete, is decreased by using
Less water
Fine aggregates
Rich mix
More water and coarse aggregates
Sand generally contains salt if it is obtained from:
Nala beds
River beds
Sea beds
None of these
Modulus of elasticity of steel as per IS: 4561978 shall be taken as
20 kN/cm²
200 kN/cm²
200 kN/mm²
2 × 106 N/cm²
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
The maximum percentage of chemical ingredient of cement is that of
Magnesium oxide
Iron oxide
Silica
Lime
Pick up the incorrect statement from the following:
Space between the exterior walls of a warehouse and bag piles should be 30 cm
Cement bags should preferably be piled on wooden planks
Width and height of the pile should not exceed 3 m and 2.70 m respectively
None of these
Le-Chatelier's apparatus is used for testing
Soundness of cement
Hardness of cement
Strength of cement
Durability of cement
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
The maximum amount of dust which may be permitted in aggregates is
5% of the total aggregates for low workability with a coarse grading
10% of the total aggregates for low workability with a fine grading
20% of the total aggregates for a mix having high workability with fine grading
All the above
Concrete mainly consists of
Cement
Aggregates
Water
All the above
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
For the design of retaining walls, the minimum factor of safety against overturning is taken as
1.5
2.0
2.5
3.0
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
Cement used for normal concrete construction, is obtained by burning a mixture of
Siliceous and argillaceous materials
Argillaceous and calcareous materials
Siliceous and calcareous materials
Siliceous, argillaceous and calcareous materials
Pick up the correct statement from the following:
Bulking of sand is caused due to formation of a thin film of surface moisture
Fine sand bulks more than coarse sand
The volume of fully saturated sand, is equal to the volume of dry and loose sand
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
In a counterfort retaining wall, the main reinforcement in the stem at mid span is provided on
Front face only
Inner face only
Both front face and inner face
None of the above
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
The commercial name of white and coloured cement in India, is
Colorcrete
Silvicrete
Snowcem
All the above
Separation of coarse aggregates from mortar during transportation, is known
Bleeding
Creeping
Segregation
Shrinkage
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
Which of the following has high tensile strength?
Plain hot rolled wires
Cold drawn wires
Heat treated rolled wires
All have same tensile strength
Curing
Reduces the shrinkage of concrete
Preserves the properties of concrete
Prevents the loss of water by evaporation
All of the above
Slump test of concrete is a measure of its
Consistency
Compressive strength
Tensile strength
Impact value
The property of the ingredients to separate from each other while placing the concrete is called
Segregation
Compaction
Shrinkage
Bulking
An aggregate is said to be flaky, if its least dimension is less than
2/3 mean dimension
3/4 mean dimension
3/5 mean dimension
5/8 mean dimension
For given workability the grading requiring the least amount of water is one that gives
Greatest surface area for the given cement and aggregates
Least surface area for the given cement and aggregates
Least weight for the given cement and aggregates
Greatest weight for the given cement and aggregates
Cube strength of controlled concrete to be used for pre-tensioned and post-tensioned work respectively should not be less than
35 MPa and 42 MPa
42 MPa and 35 MPa
42 MPa and 53 MPa
53 MPa and 42 MPa
Pick up the correct statement from the following:
The concrete gains strength due to hydration of cement
The concrete does not set at freezing point
The strength of concrete increases with its age
All the above