The maximum percentage of chemical ingredient of cement is that of
Magnesium oxide
Iron oxide
Silica
Lime
Correct Answer :
D. Lime
Related Questions
Workability of concrete for a given water content is good if the aggregates, are
Rounded aggregate
Irregular aggregate
Angular aggregate
Flaky aggregates
The critical section for finding maximum bending moment for footing under masonry wall is located
At the middle of the wall
At the edge of the wall
Halfway between the middle and edge of the wall
At a distance equal to effective depth of footing from the edge of the wall
The ratio of various ingredients (cement, sand, aggregates) in concrete of grade M 200, is
1 : 2 : 4
1 : 3 : 6
1 : 1 ½ : 3
1 : 1 : 2
The shuttering of a hall measuring 4 m × 5 m, can be removed after
5 days
7 days
10 days
14 days
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
The minimum percentage of chemical ingredient of cement is that of
Magnesium oxide
Iron oxide
Alumina
Lime
The limits of percentage p of the longitudinal reinforcement in a column is given by
0.15% to 2%
0.8% to 4%
0.8% to 6%
0.8% to 8%
Modulus of rupture of concrete is a measure of
Flexural tensile strength
Direct tensile strength
Compressive strength
Split tensile strength
For compacting plain concrete road surface of thickness less than 20 cm, we use
Internal vibrator
Screed vibrator
Form vibrator
None of these
As compared to ordinary Portland cement, high alumina cement has
Higher initial setting time but lower final setting time
Lower initial setting time but higher final setting time
Higher initial and final setting times
Lower initial and final setting times
High temperature
Increases the strength of concrete
Decreases the strength of concrete
Has no effect on the strength of concrete
None of these
Ratio of permissible stress in direct compression and bending compression is
Less than 1
Between 1 and 1.5
Between 1.5 and 2.0
Greater than 2
The most useless aggregate is one whose surface texture is
Smooth
Granular
Glassy
Honey combed and porous
For the construction of cement concrete dams, the maximum permissible size of the aggregates, is
40 mm
50 mm
60 mm
70 mm
Pick up the incorrect statement from the following:
Tricalcium silicate (C3S) hydrates rapidly
Tricalcium silicate (C3S) generates more heat of hydration
Tricalcium silicate (C3S) develops early strength
Tricalcium silicate (C3S) has more resistance to sulphate attack
Minimum thickness of load bearing RCC wall should be
50 mm
100 mm
150 mm
200 mm
Slump test of concrete is a measure of its
Consistency
Compressive strength
Tensile strength
Impact value
The compaction of concrete, improves
Density
Strength
Durability
All the above
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
During erection, the pile of length l is supported by a crane at a distance of
0.207 l
0.293 l
0.707 l
0.793 l From the driving end of pile which rests on the ground
Transport of concrete by pumps, is done for a distance of
100 m
200 m
300 m
400 m
If the slump of a concrete mix is 60 mm, its workability is
Very low
Low
Medium
High
According to IS : 382-1963, a good aggregate should be
Chemically inert
Sufficiently strong
Hard and durable
All the above
Maximum percentage reinforcement in case of slabs is limited to
2
4
6
8
'Ware house pack' of cement means
Full capacity of the ware house
Pressure exertion of the bags of upper layers
Pressure compaction of the bags on lower layers
Packing the ware house
The average permissible stress in bond for plain bars in tension is
Increased by 10% for bars in compression
Increased by 25% for bars in compression
Decreased by 10% for bars in compression
Decreased by 25% for bars in compression
For the construction of cement concrete floor, the maximum permissible size of aggregate, is
4 mm
6 mm
8 mm
10 mm
The property of the ingredients to separate from each other while placing the concrete is called
Segregation
Compaction
Shrinkage
Bulking
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)
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