APA Precast Concrete Batch Plant Operator
Questions And Answers
(True or False) Fine aggregates are those materials that are retained on a No. 4 sieve.
• True
• False ...ANSWER...False
With how many strokes should you rod each layer of concrete placed in the
compressive strength TEST MOLD?
• 10
• 15
• 20
• 25 ...ANSWER...25
(True or False) The major factor controlling the durability of concrete is its strength.
• True
• False ...ANSWER...True
How is laitance produced in concrete?
• Water collects under the surface of the CEMENT
• Cement is hydrated with saltwater
• Cement is hydrated with minimum water
• Cement is hydrated with excess water ...ANSWER...Cement is hydrated with excess
water
What percent do water reducing admixtures usually reduce the required water content
for a concrete mixture?
• 1% to 2% only
• 1% to 3%
• 3% to 7%
, • 5% to 10% ...ANSWER...5% to 10%
Concrete is denser and stronger when which condition is met?
• All voids are filled
• Voids are large and unfilled
• Aggregate particles are not solidly BONDED
• Aggregate particles are not coated with a cement-water paste ...ANSWER...All voids
are filled
Before using warehouse-packed cement, what should you do to make it free of lumps?
• Restack the sacks to allow air to circulate around them
• Raise the temperature where the sacks are stored
• Roll the sacks around
• Cover the sacks for 48 hours with tarpaulins ...ANSWER...Roll the sacks around
You are conducting a slump test. Which result indicates a poor mix?
• The concrete mix crumbles
• The concrete mix segregates
• The concrete mix falls apart
• All of the above ...ANSWER...All of the above
(True or False) Concrete has high ability to resist stretching, bending, and twisting.
• True
• False ...ANSWER...False
What is the main reason to store cement in a dry place?
• To prevent it from becoming concrete while in storage
• To prevent it from setting too fast and producing weak concrete
• To prevent it from setting too slowly and producing weak concrete
• To avoid warehouse pack ...ANSWER...To prevent it from setting too slowly and
producing weak concrete
To calculate the number of cubic yards required for a pad, divide the cubic feet of the
pad by what number?
• 27
• 28
• 30
• 40 ...ANSWER...27
Questions And Answers
(True or False) Fine aggregates are those materials that are retained on a No. 4 sieve.
• True
• False ...ANSWER...False
With how many strokes should you rod each layer of concrete placed in the
compressive strength TEST MOLD?
• 10
• 15
• 20
• 25 ...ANSWER...25
(True or False) The major factor controlling the durability of concrete is its strength.
• True
• False ...ANSWER...True
How is laitance produced in concrete?
• Water collects under the surface of the CEMENT
• Cement is hydrated with saltwater
• Cement is hydrated with minimum water
• Cement is hydrated with excess water ...ANSWER...Cement is hydrated with excess
water
What percent do water reducing admixtures usually reduce the required water content
for a concrete mixture?
• 1% to 2% only
• 1% to 3%
• 3% to 7%
, • 5% to 10% ...ANSWER...5% to 10%
Concrete is denser and stronger when which condition is met?
• All voids are filled
• Voids are large and unfilled
• Aggregate particles are not solidly BONDED
• Aggregate particles are not coated with a cement-water paste ...ANSWER...All voids
are filled
Before using warehouse-packed cement, what should you do to make it free of lumps?
• Restack the sacks to allow air to circulate around them
• Raise the temperature where the sacks are stored
• Roll the sacks around
• Cover the sacks for 48 hours with tarpaulins ...ANSWER...Roll the sacks around
You are conducting a slump test. Which result indicates a poor mix?
• The concrete mix crumbles
• The concrete mix segregates
• The concrete mix falls apart
• All of the above ...ANSWER...All of the above
(True or False) Concrete has high ability to resist stretching, bending, and twisting.
• True
• False ...ANSWER...False
What is the main reason to store cement in a dry place?
• To prevent it from becoming concrete while in storage
• To prevent it from setting too fast and producing weak concrete
• To prevent it from setting too slowly and producing weak concrete
• To avoid warehouse pack ...ANSWER...To prevent it from setting too slowly and
producing weak concrete
To calculate the number of cubic yards required for a pad, divide the cubic feet of the
pad by what number?
• 27
• 28
• 30
• 40 ...ANSWER...27
