This set of Concrete Technology Multiple Choice Questions & Answers (MCQs) focuses on “Curing of Fresh Concrete”.
1. What is curing?
Explanation: Curing refers to hydration, the chemical process by which concrete hardens once it is poured.
2. In a dry environment, concrete strength will be loosed as much as _________ % in moist environment.
Explanation: Laboratory tests show that concrete strength will be loosed as much as 50% in dry environment as compared to moist environment.
3. Concrete placed in cold weather will take __________ time to gain strength.
d) Equal to hot weather
Explanation: Concrete placed in cold weather will take longer time to gain strength, delaying form removal and subsequent construction.
4. After finishing concrete surface must be kept _________
b) First dry it and then wet it
c) First wet it and then dry it
Explanation: After finishing concrete surface must be kept wet, so that it’d be prevented from evaporation.
5. Dry intervals in surface wetting leads to __________
c) High strength
d) Good workability
Explanation: Dry intervals or patches can lead to crazing or cracking on the slab surface.
6. Contractors place blankets over the concrete to ____________
a) Increase the rate of evaporation
b) Slow the rate of evaporation
c) To increase the strength
d) Ease to do work
Explanation: A more common practice is for contractors to place blankets over the slab surface to slow the rate of evaporation.
7. Well cured concrete _________ thermal, plastic & drying shrinkage cracks.
a) Doesn’t affect
Explanation: Well cured concrete can minimize thermal, plastic & drying shrinkage cracks, making concrete more water tight, thus preventing moisture and water borne chemicals from entering into the concrete.
8. Which method is the most common and cheaper for water curing?
c) Mist curing
d) Wet covering
Explanation: Ponding is the most common and inexpensive method of curing flat surfaces such as floor slabs, flat roofs, pavements and other horizontal surfaces.
9. The hydration that provides the initial mix and chemical bond of the concrete’s ingredients is the
a) First step
b) Second step
c) Third step
d) Fourth step
Explanation: The hydration that provides the initial mix and chemical bond of the concrete’s ingredients is the first step, but in order for the slab to be properly prepared for its final finish or flooring.
10. What is the full form of rH?
a) Rhesus factor
b) Relative humidity
c) Rush hour
d) Radio head
Explanation: Relative Humidity (RH) is the ratio of the amount of water vapor in the air at a specific temperature to the maximum amount that the air could hold at that temperature.
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.