Construction Technology II

Air-entrained cement is used to:
1. Decrease workability.
2. Increase freezing/thawing resistance.
3. Increase strength.
4. Increase sulfate resistance.
How many pounds does a cubic foot of normal concrete, using fine and course aggregates, weigh?
1. 130-150
2. 140-160
3. 150-170
4. 160-180
When concrete is in a semiliquid state, it is referred to as:
1. Admixtures.
2. Cured.
3. Green.
4. Plastic.
When concrete hardens, but has not yet reached structural strength, it is called:
1. Admixtures.
2. Cured.
3. Green.
4. Plastic.
The chemical reaction that causes concrete to set up and harden is:
1. Dehydration.
2. Durability.
3. Hydration.
4. Hypertension.
Portland cement is made by heating lime, clay, shale, or slag to about:
1. 1000° F.
2. 2000° F..
3. 3000° F.
4. 4000° F.
Aggregates make up what percentage of the volume of concrete?
1. 40-60
2. 50-70
3. 60-80
4. 70-90
Average concrete contains aggregate NOT larger than what diameter?
1. 3/4"
2. 1"
3. 1-1/2"
4. 2"
High-strength concrete has a compressive strength over:
1. 4000 psi.
2. 5000 psi.
3. 6000 psi.
4. 7000 psi.

Construction Technology II - 4.02