Pick up the correct statement from the following:
Continuous grading is not necessary for obtaining a minimum of air voids
The omission of a certain size of aggregate is shown by a straight horizontal line on the grading curve
The omission of a certain size of aggregate in concrete increases the workability but also increases the liability to segregation
All the above
Correct Answer :
D. All the above
Related Questions
Saw dust can be rendered chemically inert by boiling it in water containing
Ferrous sulphate
Potassium chloride
Ammonia
Nitric acid
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
The operation of removing humps and hollows of uniform concrete surface, is known as
Floating
Screeding
Trowelling
Finishing
When shear stress exceeds the permissible limit in a slab, then it is reduced by
Increasing the depth
Providing shear reinforcement
Using high strength steel
Using thinner bars but more in number
An aggregate is said to be flaky if its least dimension is less than
1/5th of mean dimension
2/5th of mean dimension
3/5th of mean dimension
4/5th of mean dimension
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
As compared to ordinary Portland cement, use of pozzolana cement
Reduces workability
Increases bleeding
Increases shrinkage
Increases strength
The size of fine aggregates does not exceed
2.75 mm
3.00 mm
3.75 mm
4.75 mm
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 %
Proper batching ensures
Economy
Durability
Workability
All the above
The effect of adding calcium chloride in concrete is (i) To increase shrinkage (ii) To decrease shrinkage (iii) To increase setting time (iv) To decrease setting time The correct answer is
(i) and (iii)
(i) and (iv)
(ii) and (iii)
(ii) and (iv)
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
Slump test is done for
Clay
Sand
Lime
Concrete
The cement becomes useless if its absorbed moisture content exceeds
1 %
2 %
3 %
5 %
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)
Pozzolanic properties exist in
Shales
Fly ash
Pumicite
All the above
For given workability the grading requiring the least amount of water is one that gives
Greatest surface area for the given cement and aggregates
Least surface area for the given cement and aggregates
Least weight for the given cement and aggregates
Greatest weight for the given cement and aggregates
Log Angles machine is used to test the aggregate for
Crushing strength
Impact value
Abrasion resistance
Water absorption
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
Increase in the moisture content in concrete
Reduces the strength
Increases the strength
Does not change the strength
All of the above
The compaction of concrete, improves
Density
Strength
Durability
All the above
For the construction of cement concrete floor, the maximum permissible size of aggregate, is
4 mm
6 mm
8 mm
10 mm
Construction joints are provided
Where B.M. and S.F. are small
Where the member is supported by other member
At 18 m apart in huge structures
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
If the effective plan area of a warehouse is 54 sq. m, and maximum height of piles permitted is 270 cm, the number of cement bags to be stored, is
2000 bags
2200 bags
2400 bags
2700 bags
In a spherical dome the hoop stress due to a concentrated load at crown is
Compressive everywhere
Tensile everywhere
Partly compressive and partly tensile
Zero
Permissible compressive strength of M 200 concrete grade is
100 kg/cm2
150 kg/cm2
200 kg/cm2
250 kg/cm2
According to Water-Cement Ratio Law, the strength of workable plastic concrete
Depends upon the amount of water used in the mix
Does not depend upon the quality of cement mixed with aggregates
Does not depend upon the quantity of cement mixed with aggregates
All the above
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
Pick up the incorrect statement from the following:
Space between the exterior walls of a warehouse and bag piles should be 30 cm
Cement bags should preferably be piled on wooden planks
Width and height of the pile should not exceed 3 m and 2.70 m respectively
None of these