This set of Concrete Technology Multiple Choice Questions & Answers (MCQs) focuses 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
c) Prestressed concrete
d) Sawdust concrete
Explanation: 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.
Explanation: 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 Portlandcement 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
Explanation: 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
Explanation: 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.
Explanation: 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
Explanation: 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.
Explanation: 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”. Is it true or false?
Explanation: 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
Explanation: 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.
Explanation: 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.
Sanfoundry Global Education & Learning Series – Concrete Technology.
To practice all areas of Concrete Technology, here is complete set of 1000+ Multiple Choice Questions and Answers.