Concrete

Question 1

Concrete is made of what?

Answer 1

Water, Portland cement, sand, and stone… Gravel or aggregate

Question 2

Water cement ratio determines what?

Answer 2

AKA Weight Ratio determines quality and durability

Question 3

Strong stone increases what?

Answer 3

Abrasion resistance

Question 4

Large aggregate produces what?

Answer 4

More economical concrete

Question 5

Which fiber tube forms require stiffeners?

Answer 5

Fiber tube forms over 15 feet

Question 6

Maximum drop distance/pouring height?

Answer 6

5 feet

Question 7

Who specifies when forms are to be removed?

Answer 7

The engineer

Question 8

What test results are needed prior to remove shoring?

Answer 8

Compression cylinder test results

Question 9

Epoxy coating on rebar prevents what?

Answer 9

Corrosion

Question 10

Stirrup tolerance?

Answer 10

Plus or minus 1 inch

Question 11

Saw joints should be installed when?

Answer 11

Between 4 and 12 hours after the concrete is poured

Question 12

Wet ground under slab to prevent what?

Answer 12

Loss of water in concrete

Question 13

Pump mix stone should be?

Answer 13

Rounded

Question 14

What does the vibrator do?

Answer 14

Consolidates concrete. Makes stiff concrete more fluid.

Question 15

Increase in temperature and effect on set up time?

Answer 15

20° increase in temperature reduces setup time by 50%

Question 16

Temperature considered cold weather concrete?

Answer 16

Below 40°

Question 17

Slab finishing sequence?

Answer 17

Edging last step after trowel finish. Troweling too soon will cause the slab surface to be rough

Question 18

What does the bull float do?

Answer 18

Knocks down the highs and lows

Question 19

Curing controls what? When does it start? And what does it help with?

Answer 19

Curing controls the drying of concrete. It starts immediately. It helps with strength and durability.

Question 20

Cause of plastic shrinkage cracks?

Answer 20

Rapid evaporation

Question 21

Temperature for curing cylinders at jobsite in box?

Answer 21

60° to 80°

Question 22

Weight of concrete?

Answer 22

150lb/ft3