The lower water cement ratio in concrete, introduces
Smaller creep and shrinkage
Greater density and smaller permeability
Improved frost resistance
All the above
Correct Answer :
D. All the above
Related Questions
How long will it take for the concrete to achieve 100% of its strength?
7 days
14 days
21 days
28 days
Pick up the correct statement from the following:
Continuous grading is not necessary for obtaining a minimum of air voids
The omission of a certain size of aggregate is shown by a straight horizontal line on the grading curve
The omission of a certain size of aggregate in concrete increases the workability but also increases the liability to segregation
All the above
Tricalcium aluminate (C3A)
Reacts fast with water
Generates less heat of hydration
Causes initial setting and early strength of cement
Does not contribute to develop ultimate strength
For concreting of heavily reinforced sections without vibration, the workability of concrete expressed as compacting factor should be
0.75 - 0.80
0.80 - 0.85
0.85 - 0.92
Above 0.92
Examine the following statements: (i) Factor of safety for steel should be based on its yield stress, (ii) Factor of safety for steel should be based on its ultimate stress, (iii) Factor of safety for concrete should be based on its yield stress, (iv) Factor of safety for concrete should be based on its ultimate stress. The correct statements are
(i) and (iii)
(i) and (iv)
(ii) and (iii)
(ii) and (iv)
In reinforced concrete footing on soil, the minimum thickness at edge should not be less than
100 mm
150 mm
200 mm
250 mm
Modulus of rupture of concrete is a measure of
Flexural tensile strength
Direct tensile strength
Compressive strength
Split tensile strength
Concrete is unsuitable for compaction by a vibrator if it is
Dry
Earth moist
Semi-plastic
Plastic
Admixtures which cause early setting and hardening of concrete are called
Workability admixtures
Accelerators
Retarders
Air entraining agents
Batching error means inaccuracy in the quantity of
Aggregates
Cement
Water
All the above
If the effective plan area of a warehouse is 54 sq. m, and maximum height of piles permitted is 270 cm, the number of cement bags to be stored, is
2000 bags
2200 bags
2400 bags
2700 bags
Vicat apparatus is used for
Fineness test
Consistency test
Test for setting time
Test for tensile strength
Normally pre-stressing wires are arranged in the
Upper part of the beam
Lower part of the beam
Center
Anywhere
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
Ordinary concrete is not used for concrete grade
M 100
M 150
M 250
M 400
A T-shaped retaining wall mainly consists of
One cantilever
Two cantilevers
Three cantilevers
Four cantilevers
Separation of coarse aggregates from mortar during transportation, is known
Bleeding
Creeping
Segregation
Shrinkage
In a ring beam subjected to uniformly distributed load (i) Shear force at mid span is zero (ii) Shear force at mid span is maximum (iii) Torsion at mid span is zero (iv) Torsion at mid span is maximum The correct answer is
(i) and (iii)
(i) and (iv)
(ii) and (iii)
(ii) and (iv)
While compacting the concrete by a mechanical vibrator, the slump should not exceed
2.5 cm
5.0 cm
7.5 cm
10 cm
For a simply supported beam of span 15 m, the minimum effective depth to satisfy the vertical deflection limits should be
600 mm
750 mm
900 mm
More than 1 m
The produce impermeable concrete
Thorough mixing of concrete is required
Proper compaction of concrete is required
Proper curing of concrete is required
All the above
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
High temperature
Increases the strength of concrete
Decreases the strength of concrete
Has no effect on the strength of concrete
None of these
The size of fine aggregates does not exceed
2.75 mm
3.00 mm
3.75 mm
4.75 mm
You are asked to construct a massive dam, the type of cement you will use, is
Ordinary Portland cement
Rapid hardening cement
Low heat cement
Blast furnace slag cement
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
To prevent segregation, the maximum height for placing concrete, is
100 cm
125 cm
150 cm
200 cm
The main reason for providing number of reinforcing bars at a support in a simply supported beam is to resist in that zone
Compressive stress
Shear stress
Bond stress
Tensile stress
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
After casting, an ordinary cement concrete on drying
Expands
Mix
Shrinks
None of these