250+ TOP MCQs on Special Concrete and Answers

Concrete Technology Multiple Choice Questions on “Special Concrete”.

1. The cement concrete, from which entrained air and excess water are removed after placing it in position, is called ________
a) Vacuum concrete
b) LWC
c) Prestressed concrete
d) Sawdust concrete
Answer: a
Clarification: Vacuum concrete is the type of concrete in which the excess water is removed for improving concrete strength. The water is removed by use of vacuum mats connected to a vacuum pump.

2. Light weight cement content for compressive strength 3000 psi is _______ pounds per cubic yard.
a) 400-510
b) 440-560
c) 530-660
d) 630-750
Answer: b
Clarification: Light weight cement content for compressive strength 3000 psi is 440-560 pounds per cubic yard and 400-510 is for compressive strength 2500 psi.

3. The light-weight concrete is prepared by ____________
a) Mixing Portland cement with sawdust in specified proportion in the concrete
b) Using coke-breeze, slag as aggregate in the concrete
c) Mixing Al in the concrete
d) Mixing Fe in the concrete
Answer: b
Clarification: The light-weight concrete is prepared by using coke-breeze, cinder or slag as aggregate in the concrete.

4. Aerated Concrete is ______________
a) Very heavy weight
b) Heavy weight
c) Medium weight
d) Light weight
Answer: d
Clarification: Aerated concrete is also referred to as gas concrete, foam concrete, cellular concrete. In India, we have at present a few factories manufacturing aerated concrete.

5. Entrainment of air also improves workability and durability.
a) True
b) False
Answer: a
Clarification: Entrainment of air also improves workability and durability to produce such concrete which would have resistance to weathering actions.

6. No fines concrete is manufactured by _____________
a) By adding no fines materials from normal concrete
b) By eliminating no fines materials from normal concrete
c) By reducing its strength
d) By increasing its strength
Answer: b
Clarification: No fines concrete is one type of light weight concrete. As the name indicates that it is a concrete mix without fine aggregate or sand.

7. Density of no fines concrete with light weight aggregate vary from ________ kg/m³.
a) 1600-1900
b) <300
c) >2500
d) >300
Answer: b
Clarification: The range of the density of no fines aggregates with the light weight aggregates vary from less than 300 kg/m³.

8. In bridges, HDC is used.
a) True
b) False
Answer: a
Clarification: In bridges, High Density Concrete is being used to reduce the number of beams for supporting span.

9. What is the value of modulus of elasticity for Sulphur infiltered concrete?
a) 60-115 MPa
b) 10-16 MPa
c) 35-50 GPa
d) 500 GPa
Answer: c
Clarification: 35-60 GPa is the range of modulud of elasticity for the Sulphur infiltered concrete whereas the OPC has the range of 25-28 GPa.

10. Diameter of Round Steel Fiber lies in the range of ________ mm.
a) .3-.5
b) .25-.75
c) .155-.41
d) .25-.90
Answer: b
Clarification: Round steel fiber are commonly used and produced by cutting round wire into the short length. The diameter lies in the range of 0.25mm to 0.75mm.