The concrete mix which causes difficulty in obtaining a smooth finish, possess
Segregation
Internal friction
Hardness
Bleeding
Correct Answer :
C. Hardness
Related Questions
Ultimate strength of cold drawn high steel wires
Increases with increase in diameter of bar
Decreases with increase in diameter of bar
Does not depend on diameter of bar
None of the above
A beam curved in plan is designed for
Bending moment and shear
Bending moment and torsion
Shear and torsion
Bending moment, shear and torsion
For road pavements, the cement generally used, is
Ordinary Portland cement
Rapid hardening cement
Low heat cement
Blast furnace slag cement
Poisson's ratio for concrete
Remains constant
Increases with richer mixes
Decreases with richer mixes
None of the above
Specified compressive strength of concrete is obtained from cube tests at the end of
3 days
7 days
21 days
28 days
The surface where two successive placements of concrete meet, is known as
Contraction joint
Expansion joint
Construction joint
Both (a) and (b)
Due to shrinkage stresses, a simply supported beam having reinforcement only at bottom tends to
Deflect downward
Deflect upward
Deflect downward or upward
None of the above
The mixture of different ingredients of cement, is burnt at
1000°C
1200°C
1400°C
1600°C
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
Pick up the correct statement from the following:
According to the petrological characteristics, concrete aggregates are classified as heavy weight, normal weight and light weight
According to the shape of the particles, concrete aggregates are classified as rounded irregular, angular and flaky
According to the surface texture of the particles, the concrete aggregates are classified as glassy, smooth, granular, rough, crystalline, honey combed and porous
All the above
Concrete is unsuitable for compaction by a vibrator if it is
Dry
Earth moist
Semi-plastic
Plastic
For a longitudinal reinforcing bar in a column, the minimum cover shall neither be less than the diameter of bar nor less than
15 mm
25 mm
30 mm
40 mm
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
Minimum pitch of transverse reinforcement in a column is
The least lateral dimension of the member
Sixteen times the smallest diameter of longitudinal reinforcement bar to be tied
Forty-eight times the diameter of transverse reinforcement
Lesser of the above three values
Normally pre-stressing wires are arranged in the
Upper part of the beam
Lower part of the beam
Center
Anywhere
Stress strain curve of high tensile steel
Has a definite yield point
Does not show definite yield point but yield point is defined by 0.1% proof stress
Does not show definite yield point but yield point is defined by 0.2% proof stress
Does not show definite yield point but yield point is defined by 2% proof stress,
The increased cohesiveness of concrete, makes it
Less liable to segregation
More liable to segregation
More liable to bleeding
More liable for surface scaling in frosty weather
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
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)
M 150 grade of concrete approximates
1 : 3 : 6 mix
1 : 1 :2 mix
1 : 2 : 4 mix
1 : 1.5 : 3 mix
Slump test is done for
Clay
Sand
Lime
Concrete
The ratio of the diameter of reinforcing bars and the slab thickness is
1/4
1/5
1/6
1/8
Which of the following statements is incorrect?
Minimum cross sectional area of longitudinal reinforcement in a column is 0.8%
Spacing of longitudinal bars measured along the periphery of column should not exceed 300 mm
Reinforcing bars in a column should not be less than 12 mm in diameter
The number of longitudinal bars provided in a circular column should not be less than four
Sands of zone I are:
Course
Medium
Medium to fine
Fine
Pick up the incorrect statement from the following:
With passage of time, the strength of cement increases
With passage of time, the strength of cement decreases
After a period of 24 months, the strength of cement reduces to 50%
The concrete made with storage deteriorated cement, gains strength with time
The final operation of finishing floors, is known as
Screeding
Floating
Trowelling
Finishing
The ratio of the length to breadth of a wooden float, is
4.5
5.5
6.5
7.5
The following proportion of the ingredients of concrete mix, is not in conformation to arbitrary method of proportioning
1 : 1 : 2
1 : 2 : 4
1 : 3 : 6
1 : 4 : 10
The entrained air in concrete
Increases workability
Decreases workability
Decreases resistance to weathering
Increases strength
The factor which affects workability, is
Water content and its temperature
Shape and size of the aggregates
Air entraining agents
All the above