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How to Concrete in Cold and Hot Weather


Quiz Questions

1. Concrete that is cured at high temperatures at an early age will not be as strong as later ages as the same concrete cured at temperatures in the range of ________?
50 F
60 F
70 F
80 F
2. Ice can reduce concrete temperature by up to __________ .
18 F
20 F
25 F
30 F
3. Accelerating admixtures do not prevent concrete from freezing and their use does not preclude the requirements for concrete temperature and appropriate curing and protection from freezing.
True
False
4. Chilled water can reduce concrete temperature by up to __________ .
5 F
10 F
12 F
15 F
5. Cold weather is defined as a period when the average daily temperature falls below __________.
40 F
50 F
57 F
65 F
6. Cold weather conditions can produce a rapid rate of evaporation of moisture from the surface of the newly placed concrete and accelerated setting time, among other problems.
True
False
7. If Plastic concrete freezes, its potential strength can be reduced by more than _______ and its durability will be adversely affected.
20%
40%
50%
60%
8. For greater reductions in concrete temperature, ____________ can be injected into concrete mixers.
Ethyl alcohol
Shaved ice
Liquid nitrogen
All the above
9. Newly placed concrete is saturated with water and should be protected from cycles of freezing and thawing until it has attained a compressive strength of at least __________.
1000 psi
1500 psi
2000 psi
3500 psi
10. Placing concrete in cold weather provides the opportunity for better quality, as cooler initial concrete temperature will typically result in higher ultimate strength.
True
False