The preliminary test is repeated if the difference of compressive strength of three test specimens, exceeds
5 kg/cm2
8 kg/cm2
10 kg/cm2
15 kg/cm2
Correct Answer :
D. 15 kg/cm2
Related Questions
Critical section for shear in case of flat slabs is at a distance of
Effective depth of slab from periphery of column/drop panel
d/2 from periphery of column/capital/ drop panel
At the drop panel of slab
At the periphery of column
In counterfort type retaining walls (i) The vertical slab is designed as a continuous slab (ii) The heel slab is designed as a continuous slab (iii) The vertical slab is designed as a cantilever (iv) The heel slab is designed as a cantilever The correct answer is
(i) and (ii)
(i)and(iv)
(ii) and (iii)
(iii) and (iv)
The load carrying capacity of a helically reinforced column as compared to that of a tied column is about
5 % less
10 % less
5 % more
10 % more
The purpose of reinforcement in pre-stressed concrete is
To provide adequate bond stress
To resist tensile stresses
To impart initial compressive stress in concrete
All of the above
An excess of flaky particles in concrete aggregates
Decreases the workability
Increases the quantity of water and sand
More than 15% are not desirable
All the above
Concrete containing
Siliceous aggregates, has higher co-efficient of expansion
Igneous aggregates, has intermediate coefficient of expansion
Lime stones, has lowest co-efficient of expansion
All the above
For a reinforced concrete section, the shape of shear stress diagram is
Wholly parabolic
Wholly rectangular
Parabolic above neutral axis and rectangular below neutral axis
Rectangular above neutral axis and parabolic below neutral axis
If the storey height is equal to length of RCC wall, the percentage increase in strength is
0
10
20
30
Maximum percentage reinforcement in case of slabs is limited to
2
4
6
8
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
For the design of retaining walls, the minimum factor of safety against overturning is taken as
1.5
2.0
2.5
3.0
The factor of safety for
Steel and concrete are same
Steel is lower than that for concrete
Steel is higher than that for concrete
None of the above
If the average compressive strength is 4000 kg/cm2 and standard deviation is 500, the co-efficient of variation is
10 %
12.5 %
15 %
18.5 %
According to Whitney's theory, depth of stress block for a balanced section of a concrete beam is limited to
0.43 d
0.537 d
0.68 d
0.85 d Where d is effective depth of beam
The minimum cover in a slab should neither be less than the diameter of bar nor less than
10 mm
15 mm
25 mm
13 mm
To prevent segregation, the maximum height for placing concrete, is
100 cm
125 cm
150 cm
200 cm
For preparing a test-specimen, it is necessary
To mix cement and fine aggregate by dry hand
To mix coarse aggregates
To mix water to the cement, fine aggregates and coarse aggregates
All the above
The most useless aggregate is one whose surface texture is
Smooth
Granular
Glassy
Honey combed and porous
The dimensions of a 35 litre forma for measuring aggregates by volume, are:
Length 30 cm, breadth 25 cm, height 30 cm
Length 39 cm, breadth 25 cm, height 32 cm
Length 27 cm, breadth 27 cm, height 48 cm
Length 220 cm, breadth 25 cm, height 40 cm
Minimum grade of concrete to be used in reinforced concrete as per IS: 4561978 is
M 15
M 20
M 10
M 25
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
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
Concrete is unsuitable for compaction by a vibrator if it is
Dry
Earth moist
Semi-plastic
Plastic
Addition of pozzolana to ordinary port land cement, causes
Decrease in early strength
Reduction in chemical action with sulphates
Increase in shrinkage
All the above
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
On a grading curve, the gap grading is represented by
A horizontal line
A vertical line
N.W. inclined line
N.E. inclined line
The recommended value of modular ratio for reinforced brick work is
18
30
40
58
Pick up the incorrect statement applicable to the field test of good cement.
When one thrusts one's hand into a bag of cement, one should feel warm
The colour of the cement is bluish
By rubbing cement in between fingers, one should feed rough
All the above
The maximum percentage of chemical ingredient of cement is that of
Magnesium oxide
Iron oxide
Silica
Lime
Batching error means inaccuracy in the quantity of
Aggregates
Cement
Water
All the above