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
Correct Answer :
D. Tricalcium silicate (C3S) has more resistance to sulphate attack
Related Questions
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
According to IS : 382-1963, a good aggregate should be
Chemically inert
Sufficiently strong
Hard and durable
All the above
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
Curing
Reduces the shrinkage of concrete
Preserves the properties of concrete
Prevents the loss of water by evaporation
All of the above
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
For the construction of thin R.C.C. structures, the type of cement to be avoided, is
Ordinary Portland cement
Rapid hardening cement
Low heat cement
Blast furnace slag cement
Grading of sand causes great variation in
Workability of concrete
Strength of concrete
Durability of concrete
All the above
If the permissible stress in steel in tension is 140 N/mm², then the depth of neutral axis for a singly reinforced rectangular balanced section will be
0.35 d
0.40 d
0.45 d
Dependent on grade of concrete also
Shrinkage in concrete can be reduced by using
Low water cement ratio
Less cement in the concrete
Proper concrete mix
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
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
Saw dust can be rendered chemically inert by boiling it in water containing
Ferrous sulphate
Potassium chloride
Ammonia
Nitric acid
A concrete having a slump of 6.5 cm, is said to be
Dry
Earth moist
Semi-plastic
Plastic
Workability of concrete for a given water content is good if the aggregates, are
Rounded aggregate
Irregular aggregate
Angular aggregate
Flaky aggregates
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
Bulking of sand is maximum if moisture content is about
2 %
4 %
6 %
10 %
An ordinary Portland cement when tested for its fineness, should not leave any residue on I.S. sieve No. 9, more than
5 %
10 %
15 %
20 %
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
The load carrying capacity of a helically reinforced column as compared to that of a tied column is about
5 % less
10 % less
5 % more
10 % more
To obtain cement dry powder, lime stones and shales or their slurry, is burnt in a rotary kiln at a temperature between
1100° and 1200°C
1200° and 1300°C
1300° and 1400°C
1400° and 1500°C
An aggregate is said to be flaky, if its least dimension is less than
2/3 mean dimension
3/4 mean dimension
3/5 mean dimension
5/8 mean dimension
The factor which affects workability, is
Water content and its temperature
Shape and size of the aggregates
Air entraining agents
All the above
To hydrate 500kg of cement full water needed, is
100 kg
110 kg
120 kg
130 kg
Admixtures which cause early setting and hardening of concrete are called
Workability admixtures
Accelerators
Retarders
Air entraining agents
The most useless aggregate is one whose surface texture is
Smooth
Granular
Glassy
Honey combed and porous
If a grading curve is horizontal between the portions of 20 mm I.S. Sieve and 4.75 mm I.S. Sieve, the graded aggregates do not contain
20 mm particles
10 mm particles
4.75 mm particles
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
According to Water-Cement Ratio Law, the strength of workable plastic concrete
Depends upon the amount of water used in the mix
Does not depend upon the quality of cement mixed with aggregates
Does not depend upon the quantity of cement mixed with aggregates
All the above
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
The shrinkage of concrete
Is proportional to water content is the mix
Is proportional to cement concrete
Increases with age of concrete
All the above