The average permissible stress in bond for plain bars in tension is
Increased by 10% for bars in compression
Increased by 25% for bars in compression
Decreased by 10% for bars in compression
Decreased by 25% for bars in compression
Correct Answer :
B. Increased by 25% for bars in compression
Related Questions
Admixtures which cause early setting and hardening of concrete are called
Workability admixtures
Accelerators
Retarders
Air entraining agents
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
In the design of a front counterfort in a counterfort retaining wall, the main reinforcement is provided on (i) Bottom face near counterfort (ii) Top face near counterfort (iii) Bottom face near centre of span (iv) Top face near centre of span The correct answer is
Only (i)
Only (ii)
Both (i) and (iv)
Both (ii) and (iii)
Setting time of cement increases by adding
Gypsum
Hydrogen peroxide
Calcium chloride
Sodium oxide
The strength and quality of concrete, depend upon:
Grading of aggregates
Surface area of aggregates
Shape of aggregates
All the above
Pick up the correct statement from the following:
Water cement paste hardens due to hydration
During hardening cement binds the aggregates together
Cement provides strength, durability and water tightness to the concrete
All the above
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
Most common method of pre-stressing used for factory production is
Long line method
Freyssinet system
Magnel-Blaton system
Lee-Macall system
The type of aggregates of same nominal size, which contain less voids when compacted, are
Rounded spherical
Irregular
Flaky
None of these
Water cement ratio is generally expressed in volume of water required per
10 kg
20 kg
30 kg
50 kg
During erection, the pile of length l is supported by a crane at a distance of
0.207 l
0.293 l
0.707 l
0.793 l From the driving end of pile which rests on the ground
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
Permissible compressive strength of M 300 concrete grade is
100 kg/cm2
150 kg/cm2
200 kg/cm2
300 kg/cm2
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)
For given water content, workability decreases if the concrete aggregates contain an excess of
Thin particles
Flat particles
Elongated particles
All the above
Sand requiring a high water cement ratio, belongs to
Zone I
Zone II
Zone III
Zone IV
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
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
Pick up the incorrect statement from the following. While performing preliminary test on concrete
Proportions of the material and water should be the same as to be used at the work site
Cement should be mixed by hand in order to maintain uniformity
Concrete mix should be stored in air-tight containers
Concrete ingredients should be kept at a temperature of 37° ± 2°C
For preparing ordinary concrete, the quantity of water used, is
5% by weight of aggregates plus 20% of weight of cement
10% by weight of aggregates plus 10% of weight of cement
5% by weight of aggregates plus 30% of weight of cement
30% by weight of aggregates plus 10% of weight of cement
Bulking of sand is maximum if moisture content is about
2 %
4 %
6 %
10 %
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
Curing of pavements, floors, roofs and slabs, is done by
Membrane method
Ponding method
Covering surface with bags
Sprinkling water method
The percentage of the aggregate of F.M. 2.6 to be combined with coarse aggregate of F.M. 6.8 for obtaining the aggregates of F.M. 5.4, is
30 %
40 %
50 %
60 %
The aggregate containing moisture in pores and having its surface dry, is known as
Moist aggregates
Very dry aggregates
Dry aggregates
Saturated surface dry aggregate
In reinforced concrete footing on soil, the minimum thickness at edge should not be less than
100 mm
150 mm
200 mm
250 mm
To determine the modulus of rupture, the size of test specimen used is
150 × 150 × 500 mm
100 × 100 × 700 mm
150 × 150 × 700 mm
100 × 100 × 500 mm
In symmetrically reinforced sections, shrinkage stresses in concrete and steel are respectively
Compressive and tensile
Tensile and compressive
Both compressive
Both tensile
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
If the foundations of all the columns of a structure are designed on the total live and dead load basis, then
There will be no settlement of columns
There will be no differential settlement
The settlement of exterior columns will be more than interior columns
The settlement of interior columns will be more than exterior columns