Civil Engineering - Concrete Technology

11.
Pick up the incorrect statement from the following:
Workability of the concrete mix decreases with an increase in the moisture content
Concrete for which preliminary tests are conducted, is called controlled concrete
Bulking of sand depends upon the fineness of grains
Concrete mix 1 : 6 : 12, is used for mass concrete in piers.
All the above.
Answer: Option
Explanation:
No answer description is available. Let's discuss.

12.
Sand generally contains salt if it is obtained from:
nala beds
river beds
sea beds
all the above
none of these.
Answer: Option
Explanation:
No answer description is available. Let's discuss.

13.
The impurity of mixing water which affects the setting time and strength of concrete, is
sodium sulphates
sodium chlorides
sodium carbonates and bicarbonates
calcium chorides
calcium bicarbonates
Answer: Option
Explanation:
No answer description is available. Let's discuss.

14.
Pick up the correct statement from the following:
Continuous grading is not necessary for obtaining a minimum of air voids
The omission of a certain size of aggregate is shown by a straight horizontal line on the grading curve
The omission of a certain size of aggregate in concrete increases the workability but also increases the liability to segregation
All the above.
Answer: Option
Explanation:
No answer description is available. Let's discuss.

15.
Di-calcium silicate (C2S)
hydrates rapidly
generates less heat of hydration
hardens rapidly
provides less ultimate strength to cement
has less resistance to sulphate attack.
Answer: Option
Explanation:
No answer description is available. Let's discuss.