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)
Correct Answer :
D. Both (b) and (c)
Related Questions
The ratio of the diameter of reinforcing bars and the slab thickness is
1/4
1/5
1/6
1/8
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
Modulus of elasticity of steel as per IS: 4561978 shall be taken as
20 kN/cm²
200 kN/cm²
200 kN/mm²
2 × 106 N/cm²
Maximum quantity of water needed per 50 kg of cement for M 15 grade of concrete is
28 liters
30 liters
32 liters
34 liters
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
Concrete gains strength due to
Chemical reaction of cement with sand and coarse aggregates
Evaporation of water from concrete
Hydration of cement
All the above
The lower water cement ratio in concrete, introduces
Smaller creep and shrinkage
Greater density and smaller permeability
Improved frost resistance
All 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
Poisson's ratio for concrete
Remains constant
Increases with richer mixes
Decreases with richer mixes
None of the above
The percentage of reinforcement in case of slabs, when high strength deformed bars are used is not less than
0.15
0.12
0.30
1.00
If 50 kg of fine aggregates and 100 kg of coarse aggregates are mixed in a concrete whose water cement ratio is 0.6, the weight of water required for harsh mix, is
8 kg
10 kg
12 kg
14 kg
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
Minimum thickness of load bearing RCC wall should be
50 mm
100 mm
150 mm
200 mm
For a simply supported beam of span 15 m, the minimum effective depth to satisfy the vertical deflection limits should be
600 mm
750 mm
900 mm
More than 1 m
Pick up the correct statement from the following:
High percentage of C3S and low percentage of C2S cause rapid hardening
High percentage of C3S and low percentage of C2S make the cement less resistive to chemical attack
Low percentage of C3S and high percentage of C2S contribute to slow hardening
All the above
The surface where two successive placements of concrete meet, is known as
Contraction joint
Expansion joint
Construction joint
Both (a) and (b)
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
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
Batching error means inaccuracy in the quantity of
Aggregates
Cement
Water
All the above
Examine the following statements: (i) Factor of safety for steel should be based on its yield stress, (ii) Factor of safety for steel should be based on its ultimate stress, (iii) Factor of safety for concrete should be based on its yield stress, (iv) Factor of safety for concrete should be based on its ultimate stress. The correct statements are
(i) and (iii)
(i) and (iv)
(ii) and (iii)
(ii) and (iv)
While designing the pile as a column, the end conditions are nearly
Both ends hinged
Both ends fixed
One end fixed and other end hinged
One end fixed and other end free
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
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
Ratio of permissible stress in direct compression and bending compression is
Less than 1
Between 1 and 1.5
Between 1.5 and 2.0
Greater than 2
Half of the main steel in a simply supported slab is bent up near the support at a distance of x from the center of slab bearing where x is equal to (Where l is the span)
l/3
l/5
l/7
l/10
Pozzolanic properties exist in
Shales
Fly ash
Pumicite
All the above
Expansion joints are provided if the length of concrete structures exceeds
10 m
15 m
15 m
45 m
M 150 grade of concrete approximates
1 : 3 : 6 mix
1 : 1 :2 mix
1 : 2 : 4 mix
1 : 1.5 : 3 mix
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 limits of percentage p of the longitudinal reinforcement in a column is given by
0.15% to 2%
0.8% to 4%
0.8% to 6%
0.8% to 8%