Engineering :: Concrete Technology

@ : Home > Civil Engineering > Concrete Technology

161.

The cement concrete having water-cement ratio less than 0.45 by weight, causes honey-comb structure.

Correct

Incorrect

162.

Hydration of cement is due to the chemical action of water with

A.	dicalcium silicate	B.	tricalcium silicate
C.	tricalcium aluminate	D.	all of these

163.

The development of first 28 days strength is on account of the hydration of

A.	dicalcium silicate	B.	tricalcium silicate
C.	tricalcium aluminate	D.	tetra calcium alumino ferrite

164.

If the water cement ratio is more, then the

A.	strength of concrete will be less	B.	durability of concrete will be less
C.	capillary voids will be more in the physical structure of hydrated cement	D.	all of the above

165.

Water-cement ratio is, usually, expressed in

A.	litres of water required per bag of cement	B.	litres of water required per kg of cement
C.	both (a) and (b)	D.	none of these

166.

High temperature

increases

decreases

167.

The concrete mix is said to be workable if it has

A.	compatibility	B.	movability
C.	stability	D.	all of these

168.

Which of the following statement is correct?

A.	Duff Abram's law is valid only when the concrete is of workable plasticity.	B.	If the water-cement ratio is less, the strength of concrete will be less.
C.	The strength of concrete decreases with age.	D.	A rich mix of concrete provides low strength than a lean mix.

169.

At freezing point, the concrete sets easily.

Right

Wrong

170.

The internal friction between the ingredients of concrete is minimised by

A.	adopting coarse aggregates	B.	using more water
C.	reducing the surface area	D.	all of these