The centroid of compressive force, from the extreme compression fiber, in limit state design lies at a distance of (Where xu is the depth of neutral axis at the limit state of collapse)
0.367 xu
0.416 xu
0.446 xu
0.573 xu
Correct Answer :
B. 0.416 xu
Related Questions
Allowable shear strength of concrete, depends upon
Shear strength
Tensile strength
Compressive strength
None of these
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
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)
In case of hand mixing of concrete, the extra cement to be added is
5 %
10 %
15 %
20 %
Pick up the correct statement from the following:
An increase in water content must be accompanied by an increase in cement content
Angular and rough aggregates reduce the workability of the concrete
The slump of the concrete mix decreases due to an increase in temperature
All the above
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
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
Pick up the correct statement from the following:
A highly absorptive aggregate reduces the workability of concrete considerably
The specific gravity of aggregate is important for the determination of the moisture content
The absorption and porosity of an aggregate influence the property of the concrete
All the above
The percentage of voids in cement is approximately
25 %
40 %
60 %
80 %
According to I.S. : 456, the number of grades of concrete mixes, is
3
4
5
7
Maximum percentage reinforcement in case of slabs is limited to
2
4
6
8
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
Pick up the correct statement from the following:
Calcium chloride acts as a retarder
Calcium chloride acts as an accelerator
Gypsum (calcium sulphate) acts as a retarder
Both (b) and (c)
Segregation is responsible for
Honey-combed concrete
Porous layers in concrete
Surface scaling in concrete
All the above
The critical section for finding maximum bending moment for footing under masonry wall is located
At the middle of the wall
At the edge of the wall
Halfway between the middle and edge of the wall
At a distance equal to effective depth of footing from the edge of the wall
Particles of 0.002 mm size are that of
Clay
Sand
Gravel
None of these
Select the incorrect statement
Lean mixes bleed more as compared to rich ones.
Bleeding can be minimized by adding pozzolana finer aggregate
Bleeding can be increased by addition 'of calcium chloride
None of the above
Pick up the incorrect statement from the following:
Admixtures accelerate hydration
Admixtures make concrete water proof
Admixtures make concrete acid proof
Admixtures give high strength
Pick up the correct statement from the following:
Lime in excess, causes the cement to expand and disintegrate
Silica in excess, causes the cement to set slowly
Alumina in excess, reduces the strength of the cement
All the above
Le-Chatelier's apparatus is used for testing
Soundness of cement
Hardness of cement
Strength of cement
Durability of cement
Pick up the correct statement from the following:
The maximum size of a coarse aggregate, is 75 mm and minimum 4.75 mm
The maximum size of the fine aggregate, is 4.75 mm and minimum 0.075 mm
The material having particles of size varying from 0.06 mm to 0.002 mm, is known as silt
All the above
The impurity of mixing water which affects the setting time and strength of concrete, is
Sodium sulphates
Sodium chlorides
Sodium carbonates and bicarbonates
Calcium bicarbonates
Higher workability of concrete is required if the structure is
Made with cement concrete
Thick and reinforced
Thin and heavily reinforced
Thick and heavily reinforced
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
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
In a counterfort retaining wall, the main reinforcement in the stem at mid span is provided on
Front face only
Inner face only
Both front face and inner face
None of the above
The final operation of finishing floors, is known as
Screeding
Floating
Trowelling
Finishing
Workability of concrete for a given water content is good if the aggregates, are
Rounded aggregate
Irregular aggregate
Angular aggregate
Flaky aggregates
Pick up the correct statement from the following:
Sand obtained from pits, is washed to remove clay and silt
Sand obtained from flooded pits, need not be washed before use
The chloride in sea shore sand and shingle may cause corrosion of reinforcement if the concrete is porous
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