Workability of concrete is directly proportional to
Aggregate cement ratio
Time of transit
Grading of the aggregate
All of above
Correct Answer :
C. Grading of the aggregate
Related Questions
For concreting of heavily reinforced sections without vibration, the workability of concrete expressed as compacting factor should be
0.75 - 0.80
0.80 - 0.85
0.85 - 0.92
Above 0.92
In case of hand mixing of concrete, the extra cement to be added is
5 %
10 %
15 %
20 %
Hardening of cement occurs at
Rapid rate during the first few days and afterwards it continues to increase at a decreased rate
Slow rate during the first few days and afterwards it continues to increase at a rapid rate
Uniform rate throughout its age
None of these
Sinking of an intermediate support of a continuous beam (i) Reduces the negative moment at support (ii) Increases the negative moment at support (iii) Reduces the positive moment at center of span (iv) Increases the positive moment at center of span The correct answer is
(i) and (iii)
(i) and (iv)
(ii) and (iii)
(ii) and (iv)
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
How long will it take for the concrete to achieve 100% of its strength?
7 days
14 days
21 days
28 days
According to IS: 4561978, minimum slenderness ratio for a short column is
Less than 12
Less than 18
Between 18 and 24
More than 24
Sand requiring a high water cement ratio, belongs to
Zone I
Zone II
Zone III
Zone IV
Workability improved by adding
Fly ash
Hydrated lime
Calcium chloride
All the above
The diameter of ties in a column should be
More than or equal to one fourth of diameter of main bar
More than or equal to 5 mm
More than 5 mm but less than one-fourth of diameter of main bar
More than 5 mm and also more than one-fourth of diameter of main bar
An aggregate which passes through 25 mm I.S. sieve and is retained on 20 mm sieve, is said to be flaky if its least dimension is less than
22.5 mm
18.5 mm
16.5 mm
13.5 mm
If the average compressive strength is 4000 kg/cm2 and standard deviation is 500, the co-efficient of variation is
10 %
12.5 %
15 %
18.5 %
In a pile of length l, the points of suspension from ends for lifting it are located at
0.207 l
0.25 l
0.293 l
0.333 l
Which of the following statements is incorrect?
Higher Vee-Bee time shows lower workability
Higher slump shows higher workability
Higher compacting factor shows higher workability
None of the above
The process of proper and accurate measurement of concrete ingredients for uniformity of proportion, is known
Grading
Curing
Mixing
Batching
Pick up the incorrect statement from the following. For performing compressive strength test of cement
Cement and standard sand mortar are used in the ratio of 1 : 3
Water is added at the rate of (P/4) + 3.0 percentage of water where P is the percentage of water for standard consistency
A cube mould of 10 cm × 10 cm × 10 cm is used
The prepared moulds are kept in a atmosphere of 50% relative humidity
Separation of water or water sand cement from a freshly concrete, is known
Bleeding
Creeping
Segregation
Flooding
The concrete mix which causes difficulty in obtaining a smooth finish, possess
Segregation
Internal friction
Hardness
Bleeding
The maximum percentage of chemical ingredient of cement is that of
Magnesium oxide
Iron oxide
Silica
Lime
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
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:
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
The type of aggregates not suitable for high strength concrete and for pavements subjected to tension, is
Rounded aggregate
Irregular aggregate
Angular aggregate
Flaky aggregate
In counterfort retaining walls, the main reinforcement in the stem at support is
Not provided
Provided only on inner face
Provided only on front face
Provided both on inner and front faces
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
The light weight aggregates are obtained from
Sedimentary rocks
Metamorphic rocks
Igneous rocks
Volcanic source
A concrete using an air entrained cement
Has strength less than 10% to 15%
Has more resistance to weathering
Is more plastic and workable
Is free from segregation and bleeding
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
The fineness modulus of fine aggregate is in the range of
2.0 to 3.5
3.5 to 5.0
5.0 to 7.0
6.0 to 8.5
The minimum cover to the ties or spirals should not be less than
15 mm
20 mm
25 mm
50 mm