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
Correct Answer :
D. None of the above
Related Questions
The shuttering of a hall measuring 4 m × 5 m, can be removed after
5 days
7 days
10 days
14 days
Workability of concrete is measured by
Vicat apparatus test
Slump test
Minimum void method
Talbot Richard test
Specified compressive strength of concrete is obtained from cube tests at the end of
3 days
7 days
21 days
28 days
The purpose of reinforcement in pre-stressed concrete is
To provide adequate bond stress
To resist tensile stresses
To impart initial compressive stress in concrete
All of the above
To hydrate 500kg of cement full water needed, is
100 kg
110 kg
120 kg
130 kg
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
The minimum percentage of chemical ingredient of cement is that of
Magnesium oxide
Iron oxide
Alumina
Lime
According to IS: 4561978, the column or the strut is the member whose effective length is greater than
The least lateral dimension
2 times the least lateral dimension
3 times the least lateral dimension
4 times the least lateral dimension
For the construction of cement concrete floor, the maximum permissible size of aggregate, is
4 mm
6 mm
8 mm
10 mm
In a ring beam subjected to uniformly distributed load (i) Shear force at mid span is zero (ii) Shear force at mid span is maximum (iii) Torsion at mid span is zero (iv) Torsion at mid span is maximum The correct answer is
(i) and (iii)
(i) and (iv)
(ii) and (iii)
(ii) and (iv)
Sand generally contains salt if it is obtained from:
Nala beds
River beds
Sea beds
None of these
Permissible compressive strength of M 150 concrete grade is
100 kg/cm2
150 kg/cm2
200 kg/cm2
250 kg/cm2
For given water content, workability decreases if the concrete aggregates contain an excess of
Thin particles
Flat particles
Elongated particles
All the above
A flaky aggregate is said to be elongated if its length is
Equal to the mean size
Twice the mean size
Thrice the mean size
Four times the mean size
The process of hardening the concrete by keeping its surface moist is known
Placing
Wetting
Curing
Compacting
In a counterfort retaining wall, the main reinforcement is provided on the (i) Bottom face in front counterfort (ii) Inclined face in front counterfort (iii) Bottom face in back counterfort (iv) Inclined face in back counterfort The correct answer is
(i) and (ii),
(ii) and (iii)
(i) and (iv)
(iii) and (iv)
Wp and Wf are the weights of a cylinder containing partially compacted and fully compacted concrete. If the compaction factor (Wp/Wf) is 0.95, the workability of concrete is
Extremely low
Very low
Low
High
I.S. Sieve Nos. 10 mm and 4.75 mm are generally used for grading of
Coarse aggregates
Fine aggregates
Neither (a) nor (b)
Both (a) and (b)
Cube strength of controlled concrete to be used for pre-tensioned and post-tensioned work respectively should not be less than
35 MPa and 42 MPa
42 MPa and 35 MPa
42 MPa and 53 MPa
53 MPa and 42 MPa
Increase in the moisture content in concrete
Reduces the strength
Increases the strength
Does not change the strength
All of the above
Separation of coarse aggregates from mortar during transportation, is known
Bleeding
Creeping
Segregation
Shrinkage
For an ordinary Portland cement
Residual does not exceed 10% when sieved through IS Sieve No. 9
Soundness varies from 5 to 10 mm
Initial setting time is not less than 30 minutes
Compressive stress after 7 days, is not less than 175 kg/cm2
Addition of pozzolana to cement causes
Reduction in permeability
Loss of heat of hydration
Reduction in bleeding
All the above
Pick up the correct statement from the following:
Bulking of sand is caused due to formation of a thin film of surface moisture
Fine sand bulks more than coarse sand
The volume of fully saturated sand, is equal to the volume of dry and loose sand
All the above
In pre-stressed concrete
Forces of tension and compression change but lever arm remains unchanged
Forces of tension and compressions remain unchanged but lever arm changes with the moment
Both forces of tension and compression as well as lever arm change
Both forces of tension and compression as well as lever arm remain unchanged
Di-calcium silicate (C2S)
Hydrates rapidly
Generates less heat of hydration
Hardens rapidly
Provides less ultimate strength to cement
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
According to I.S. : 456, the number of grades of concrete mixes, is
3
4
5
7
The design yield stress of steel according to IS: 4561978 is: (Where fy is the characteristic yield strength of steel)
0.37 fy
0.57 fy
0.67 fy
0.87 fy
The compressive strength of 100 mm cube as compared to 150 mm cube is always
Less
More
Equal
None of the above