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ACI (AMERICAN CONCRETE INSTITUTE) GRADE 1
WRITTEN EXAM 2024 STUDY GUIDE ACTUAL EXAM 200
QUESTIONS WITH DETAILED VERIFIED ANSWERS (100%
CORRECT ANSWERS) ALREADY GRADED A
What method of consolidation must be used when the
slump is greater than 75 mm (3 in) (C138/C138M -
17a, Density (unit weight), yields, and air content
(gravimetric) of concrete) - ....ANSWER >>>>Rodding
What method of consolidation must be used when the
slump is less than 1 in. (25 mm]? (C138/C138M - 17a,
Density (unit weight), yields, and air content
(gravimetric) of concrete) - ....ANSWER >>>>Vibration
If rodding is the method of consolidation being used,
the measure must be filled in how many layers?
(C138/C138M - 17a, Density (unit weight), yields, and
air content (gravimetric) of concrete) - ....ANSWER
>>>>3
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For a measure of 0.5 ft^3 [14 L], what is the required
number of strokes of the tamping rod for
consolidation of each layer? (C138/C138M - 17a,
Density (unit weight), yields, and air content
(gravimetric) of concrete) - ....ANSWER >>>>25
When rodding the middle and the top layers, the
tamping rod should penetrate into the layer below
approximately ___. (C138/C138M - 17a, Density (unit
weight), yields, and air content (gravimetric) of
concrete) - ....ANSWER >>>>25 mm (1 in)
If vibration is the method of consolidation, the
measure must be filled in _____ approximately equal
layers. (C138/C138M - 17a, Density (unit weight),
yields, and air content (gravimetric) of concrete) -
....ANSWER >>>>2
If, after consolidation of the final layer, the concrete
level is 1/2 in. (13 mm) above the top of the measure,
what should be done? (C138/C138M - 17a, Density
(unit weight), yields, and air content (gravimetric) of
concrete) - ....ANSWER >>>>Remove a representative
portion of the excess concrete with a trowel or scoop.
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After consolidation of the final layer, an excess of
concrete ____ above the top of the measure is
considered optimum. (C138/C138M - 17a, Density
(unit weight), yields, and air content (gravimetric) of
concrete) - ....ANSWER >>>>3 mm (1/8 in)
After completing the strike-off procedure, what must
be done before weighing the measure and sample?
(C138/C138M - 17a, Density (unit weight), yields, and
air content (gravimetric) of concrete) - ....ANSWER
>>>>Clean off any excess concrete
V = 0.01427 m3
Mass of empty = 8.89 kg
Mass with sample = 41.78 kg
Want D (21) (C138/C138M - 17a, Density (unit weight),
yields, and air content (gravimetric) of concrete) -
....ANSWER >>>>2305 kg/m3 (143.8 lb/ft3)
Mass with sample: 41.78 kg
Minus mass without sample: 8.89 kg
Mass of sample: 32.89 kg
D= M/V
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V = 0.01427 m3
Use density from earlier question to solve
(C138/C138M - 17a, Density (unit weight), yields, and
air content (gravimetric) of concrete) (22) - ....ANSWER
>>>>Yield per batch 189.8 ft3
Y = M/D
Want relative yield (C138/C138M - 17a, Density (unit
weight), yields, and air content (gravimetric) of
concrete) (23) - ....ANSWER >>>>1.00
Y/Yd
189.9 ft3/189 ft3
Calc did content from D in earlier question
(C138/C138M - 17a, Density (unit weight), yields, and
air content (gravimetric) of concrete) (24) - ....ANSWER
>>>>5.0 %
(151.4-143.8)/151.4 * 100 = 5.0%
The pressure method of determining air content can
be used on concrete containing _____ _____
aggregate. (C231/C231M - 17a, air content of freshly
