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
Correct Answer :
B. 75 mm
Related Questions
Pozzolana cement is used with confidence for construction of
Dams
Massive foundations
R.C.C. structures
All the above
Construction joints are generally provided in concrete
Roads
Retaining walls
Lining of canals
All the above
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
The ratio of the diameter of reinforcing bars and the slab thickness is
1/4
1/5
1/6
1/8
Due to circumferential action of the spiral in a spirally reinforced column
Capacity of column is decreased
Ductility of column reduces
Capacity of column is decreased but ductility of column increases
Both the capacity of column and ductility of column increase
The recommended value of modular ratio for reinforced brick work is
18
30
40
58
Grading of sand causes great variation in
Workability of concrete
Strength of concrete
Durability of concrete
All the above
Ordinary concrete is not used for concrete grade
M 100
M 150
M 250
M 400
Under normal conditions using an ordinary cement, the period of removal of the form work, is:
7 days for beam soffits
14 days for bottom slabs of spans 4.6 m and more
21 days for bottom beams over 6 m spans
All the above
Admixtures which cause early setting and hardening of concrete are called
Workability admixtures
Accelerators
Retarders
Air entraining agents
The main reinforcement in the toe of a T-shaped R C. retaining wall is provided on
(i) Top face parallel to the wall
(ii) Top face perpendicular to the wall
(iii) Bottom face parallel to the wall
(iv) Bottom face perpendicular to the wall The correct answer is
Only (ii) is correct
(i) and (ii) are correct
(iii) and (iv) are correct
Only (iv) is correct
The maximum percentage of chemical ingredient of cement is that of
Magnesium oxide
Iron oxide
Silica
Lime
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
The design yield stress of steel according to IS: 4561978 is: (Where fy is the characteristic yield strength of steel)
0.37 fy
0.57 fy
0.67 fy
0.87 fy
Workability of concrete is inversely proportional to
Time of transit
Water-cement ratio
The air in the mix
Size of aggregate
For a cantilever of effective depth of 0.5 m, the maximum span to satisfy vertical deflection limit is
3.5 m
4 m
4.5 m
5 m
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
If the depth of actual neutral axis in a beam is more than the depth of critical neutral axis, then the beam is called
Balanced beam
Under-reinforced beam
Over-reinforced beam
None of the above
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
To ensure constant moisture content in aggregates
Area of each aggregate pile should be large
Height of each aggregate pile should not exceed 1.50 m
Aggregate pile should be left for 24 hours before aggregates are used
All the above
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
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 load factors for live load and dead load are taken respectively as
1.5 and 2.2
2.2 and 1.5
1.5 and 1.5
2.2 and 2.2
The grade of concrete M 150 means that compressive strength of a 15 cm cube after 28 days, is
100 kg/cm2
150 kg/cm2
200 kg/cm2
250 kg/cm2
An ordinary Portland cement when tested for its fineness, should not leave any residue on I.S. sieve No. 9, more than
5 %
10 %
15 %
20 %
The process of mixing, transporting, placing and compacting concrete using Ordinary Port land Cement should not take more than
30 minutes
40 minutes
60 minutes
90 minutes
In working stress design, permissible bond stress in the case of deformed bars is more than that in plain bars by
10 %
20 %
30 %
40 %
The type of aggregates of same nominal size, which contain less voids when compacted, are
Rounded spherical
Irregular
Flaky
None of these
To obtain cement dry powder, lime stones and shales or their slurry, is burnt in a rotary kiln at a temperature between
1100° and 1200°C
1200° and 1300°C
1300° and 1400°C
1400° and 1500°C
Internal friction between the ingredients of concrete, is decreased by using
Less water
Fine aggregates
Rich mix
More water and coarse aggregates