5-51.
A total of how many cubic yards
of concrete is required for a pad
60 feet in length, by 30 feet in
width, with a depth of 4 inches
and a waste factor of 10 percent?
1.
24.2
2.
22.0
3.
59.4
4.
65.3
5-52.
Batching by volume provides
greater accuracy and avoids
problems created by the bulking
of damp sand.
1.
True
2.
False
5-53.
When mixing concrete in a transit
mixer, what is the maximum number
of revolutions of the drum at
mixing speed that you should use?
1.
60
2.
70
3.
90
4.
100
5-54.
What is the minimum agitating
speed on a transit mixer?
1.
1 revolution per minute
2.
2 revolutions per minute
3.
3 revolutions per minute
4.
4 revolutions per minute
5-55.
Concrete that is kept agitated can
generally be placed within what
maximum time period after mixing?
1.
3 1/2 hours
2.
2 1/2 hours
3.
1 1/2 hours
4.
1/2 hour
5-56.
On a mobile concrete mixer plant,
the sand and aggregate are
accurately proportioned according
to what measurement(s)
1.
By cubic feet of material only
2.
By cubic yards of material
only
3.
By weight or by cubic feet
4.
By weight or by volume
5-57.
You are conducting a slump test.
Which of the following results
indicate a poor mix?
1.
The concrete mix crumbles
2.
The concrete mix segregates
3.
The concrete mix falls apart
4.
Each of the above
5-58.
When working around cement, you
should pay particular attention
to any rash on your skin because
a rash may indicate cement
poisoning.
1.
True
2.
False
Learning Objective: Describe the
operations of an asphalt plant.
5-59.
On a batch plant, the size of
a batch varies according to the
capacity of what component?
1.
The hopper
2.
The dryer
3.
The pugmill
4.
The screens
5-60.
The proper amount of aggregates
for asphalt mixes is initially
controlled by a uniform flow of
the aggregate through what
component?
1.
Cold-feed adjustment
2.
Hot-feed adjustment
3.
Cold-bin capacity
4.
Hot-bin capacity
5-61.
The overloading of the screens
with aggregate underscores a need
for control of what factor?
1.
Proper dryer control
2.
Proper weigh-hopper
calibration
3.
Proper cold feeding
4.
Proper gradation control
calibration
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