Percentage of pozzolanic material containing clay upto 80% used for the manufacture of pozzolana cement, is
30 %
40 %
50 %
60 %
Correct Answer :
A. 30 %
Related Questions
For a good concrete
Aggregates should be hard and durable
Water should be free from organic materials
Cement should be sufficient to produce the required strength
All the above
Slump test is done for
Clay
Sand
Lime
Concrete
If the depth of moist sand in a cylinder is 15 cm and the depth of the sand when fully inundated with water is 12 cm, the bulking of the moist sand, is
10 %
12 %
15 %
25 %
If fineness modulus of sand is 2.5, it is graded as
Very fine sand
Fine sand
Medium sand
Coarse sand
Slump test of concrete is a measure of its
Consistency
Compressive strength
Tensile strength
Impact value
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 %
Pick up the incorrect statement applicable to the field test of good cement.
When one thrusts one's hand into a bag of cement, one should feel warm
The colour of the cement is bluish
By rubbing cement in between fingers, one should feed rough
All the above
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
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
High temperature
Increases the strength of concrete
Decreases the strength of concrete
Has no effect on the strength of concrete
None of these
Poisson's ratio for concrete
Remains constant
Increases with richer mixes
Decreases with richer mixes
None of the above
Pick up the correct statement from the following:
Water enables chemical reaction to take place with cement
Water lubricates the mixture of gravel, sand and cement
Strength of concrete structure largely depends upon its workability
All the above
To ensure constant moisture content in aggregates
Area of each aggregate pile should be large
Height of each aggregate pile should not exceed 1.50 m
Aggregate pile should be left for 24 hours before aggregates are used
All the above
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 %
To minimise the effect of differential settlement, the area of a footing should be designed for
Dead load only
Dead load + live load
Dead load + fraction of live load
Live load + fraction of dead load
Select the incorrect statement
The loss of pre-stress is more in pre-tensioning system than in posttensioning system.
Pre-tensioning system has greater certainty about its durability.
For heavy loads and large spans in buildings or bridges, posttensioning system is cheaper than pre-tensioning system
None of the above
To obtain a very high strength concrete, use very fine grained
Granite
Magnetite
Barite
Volcanic scoria
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
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)
Specified compressive strength of concrete is obtained from cube tests at the end of
3 days
7 days
21 days
28 days
According to Whitney's theory, ultimate strain of concrete is assumed to be
0.03 %
0.1 %
0.3 %
3 %
Finer grinding of cement
Affects only the early development of strength
Affects only the ultimate strength
Both (A) and (B)
Does not affect the strength
Curing a concrete for long period ensures better
Volume stability
Strength
Water resistance
All the above
Pick up the correct proportions of chemical ingredients of cement
Lime : Silica : Alumina : Iron oxide : 63 : 22 : 6 : 3
Silica : Lime : Alumina : Iron oxide : 63 : 22 : 6 : 3
Alumina : Silica : Lime : Iron oxide : 63 : 22 : 6 : 3
Iron oxide : Alumina : Silica : Lime : 63 : 22 : 6 : 3
Modulus of elasticity of steel as per IS: 4561978 shall be taken as
20 kN/cm²
200 kN/cm²
200 kN/mm²
2 × 106 N/cm²
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)
Workability of concrete is directly proportional to
Aggregate cement ratio
Time of transit
Grading of the aggregate
All of above
According to IS : 382-1963, a good aggregate should be
Chemically inert
Sufficiently strong
Hard and durable
All the above
The increased cohesiveness of concrete, makes it
Less liable to segregation
More liable to segregation
More liable to bleeding
More liable for surface scaling in frosty weather
Gypsum is added for
Colour
Strength
Controlling setting time
None of these