Modulus of rupture of concrete is a measure of
Flexural tensile strength
Direct tensile strength
Compressive strength
Split tensile strength
Correct Answer :
A. Flexural tensile strength
Related Questions
Log Angles machine is used to test the aggregate for
Crushing strength
Impact value
Abrasion resistance
Water absorption
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)
The light weight aggregates are obtained from
Sedimentary rocks
Metamorphic rocks
Igneous rocks
Volcanic source
Joints in concrete structures, are provided
To reduce the tensile stresses likely to be developed due to evaporation of water
To minimise the change in the dimensions of the slab
To minimise the necessary cracking
All the above
The void ratio of
Single size coarse aggregate is roughly 0.45
Graded coarse aggregate is roughly 0.040
Fine aggregate is roughly 0.45
All the above
For given water content, workability decreases if the concrete aggregates contain an excess of
Thin particles
Flat particles
Elongated particles
All the above
According to I.S. : 456, the number of grades of concrete mixes, is
3
4
5
7
Pick up the correct statement from the following:
Cement should be mixed for at least one minute
10% of water is placed in the rotating drum before adding dry material
10% of water is added after placing the other ingredients in the drum
All the above
To hydrate 500kg of cement full water needed, is
100 kg
110 kg
120 kg
130 kg
Pick up the incorrect statement from the following:
In properly graded aggregates, bulk density is more
In single size aggregates, bulk density is least
In single size aggregates, bulk density is maximum
None of these
A concrete having a slump of 6.5 cm, is said to be
Dry
Earth moist
Semi-plastic
Plastic
Addition of pozzolana to ordinary port land cement, causes
Decrease in early strength
Reduction in chemical action with sulphates
Increase in shrinkage
All the above
Pick up the correct statement from the following:
Higher workability indicates unexpected increase in the moisture content
Higher workability indicates deficiency of sand
If the concrete mix is dry, the slump is zero
All the above
The operation of removing humps and hollows of uniform concrete surface, is known as
Floating
Screeding
Trowelling
Finishing
The shuttering of a hall measuring 4 m × 5 m, can be removed after
5 days
7 days
10 days
14 days
While designing an air entrained concrete
Water cement ratio is reduced
Proportion of aggregates is reduced
An allowance for the entrained air is made
All the above
The most useless aggregate is one whose surface texture is
Smooth
Granular
Glassy
Honey combed and porous
According to IS: 4561978, the flexural strength of concrete is
Directly proportional to compressive strength
Inversely proportional to compressive strength
Directly proportional to square root of compressive strength
Inversely proportional to square root of compressive strength
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
Workability improved by adding
Fly ash
Hydrated lime
Calcium chloride
All the above
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
For compacting plain concrete road surface of thickness less than 20 cm, we use
Internal vibrator
Screed vibrator
Form vibrator
None of these
Slump test of concrete is a measure of its
Consistency
Compressive strength
Tensile strength
Impact value
The approximate value of the ratio between direct tensile strength and flexural strength is
0.33
0.5
0.75
1.0
Water required per bag of cement, is
7 kg
14 kg
21 kg
35 kg
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
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
Permissible compressive strength of M 200 concrete grade is
100 kg/cm2
150 kg/cm2
200 kg/cm2
250 kg/cm2
High carbon content in the steel causes
Decrease in tensile strength but increase in ductility
Increase in tensile strength but decrease in ductility
Decrease in both tensile strength and ductility
Increase in both tensile strength and ductility
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