The light weight aggregates are obtained from
Sedimentary rocks
Metamorphic rocks
Igneous rocks
Volcanic source
Correct Answer :
D. Volcanic source
Related Questions
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
Slump test of concrete is a measure of its
Consistency
Compressive strength
Tensile strength
Impact value
As compared to ordinary Portland cement, high alumina cement has
Higher initial setting time but lower final setting time
Lower initial setting time but higher final setting time
Higher initial and final setting times
Lower initial and final setting times
The condition not applicable to water cement ratio law, is
Internal moisture conditions on hydration continue till complete strength is gained
Concrete specimens may be tested at any temperature
Concrete specimens need be of same age
Concrete specimens need be of same size
To prevent segregation, the maximum height for placing concrete, is
100 cm
125 cm
150 cm
200 cm
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,
For construction of structures in sea water, the cement generally preferred to, is
Portland-pozzolana cement
Quick setting cement
Low heat Portland cement
Rapid hardening cement
If the various concrete ingredients i.e. cement, sand and aggregates are in the ratio of 1:3:6, the grade of concrete, is
M 100
M 150
M 200
M 250
The datum temperature for maturity by Plowman, is
23°C
0°
- 5.6°C
- 11.7°C
The depth of footing for an isolated column is governed by (i) Maximum bending moment (ii) Shear force (iii) Punching shear The correct answer is
Only (i)
(i) and (ii)
(i) and (iii)
All (i), (ii) and (iii)
Bulking of sand is maximum if moisture content is about
2 %
4 %
6 %
10 %
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 %
Admixtures which cause early setting and hardening of concrete are called
Workability admixtures
Accelerators
Retarders
Air entraining agents
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 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
For compacting plain concrete road surface of thickness less than 20 cm, we use
Internal vibrator
Screed vibrator
Form vibrator
None of these
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 %
An excess of flaky particles in concrete aggregates
Decreases the workability
Increases the quantity of water and sand
More than 15% are not desirable
All the above
The compressive strength of 100 mm cube as compared to 150 mm cube is always
Less
More
Equal
None of the above
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
According to Whitney's theory, depth of stress block for a balanced section of a concrete beam is limited to
0.43 d
0.537 d
0.68 d
0.85 d Where d is effective depth of beam
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
Too wet concrete may cause
Weakness of concrete
Excessive laitance
Segregation
All the above
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
In symmetrically reinforced sections, shrinkage stresses in concrete and steel are respectively
Compressive and tensile
Tensile and compressive
Both compressive
Both tensile
Proper proportioning of concrete, ensures
Desired strength and workability
Desired durability
Water tightness of the structure
All the above
In the method of voids for determination of the quantity of cement paste, it is assumed that
Voids in coarse aggregates are filled by fine aggregates
Voids in fine aggregates are filled by the cement paste
Volume of fine aggregates is equal to total voids in coarse aggregates plus 10% extra
All the above
Pick up the incorrect statement from the following:
The bottom and top ends of slump mould are parallel to each other
The axis of the mould is perpendicular to the end faces
The internal surface of the mould is kept clean and free from set cement
The mould is in the form of a frustum of hexagonal pyramid
Pick up the correct statement from the following:
Construction joints in columns are provided a few cm below the junction of beam
Construction joints in columns are provided at the bottom hunching
Construction joints in beams and slabs are provided within middle third
All the above
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