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When rodding the concrete sample, what is the specified number of strokes required for
each layer? -answer-25
Vibration of the concrete sample is not allowed when the slump of concrete exceeds
_____. -answer-75 mm (3 in.)
In rodding the sample, how deep should the rod penetrate each layer? -answer-Rod
bottom layer to full depth; rod second and final layer penetrating the previous layer
about 25 mm (1 in.)
After rodding each layer, what should be done to the measure before adding another
layer of concrete? -answer-Tap the sides of the measure smartly 10 to 15 times with
the mallet
When consolidating the concrete by vibration, how many times should the vibrator be
inserted into each layer? -answer-Three (3)
What tools may be used to strike off the top surface of the concrete following
consolidation of the final layer? -answer-A strike-off bar; a metal, glass, or acrylic plate
What must be done if there is a slight deficiency in the quantity of concrete in the
measure of consolidation of final layer? -answer-Add a quantity of representative
concrete before strike off
What must be done if there is an excessive amount of concrete in measure following
consolidation of the final layer? -answer-Remove a representative quantity of concrete
with the scoop or trowel before the strike off
, The volumetric method of determining air content of concrete can be used on concrete
containing what types of aggregate? -answer-All types of aggregate
STARTING SECTION C173 -answer-
What are the requirements for the tamping rod used in the test method? -answer-
Round, straight 5/8 [16 mm] +- 1/16 in. [2 mm] diameter rod at least 5 in. [300 mm]
greater in length than the depth of the bowl being used, with the tamping end rounded
to a hemispherical tip of the same diameter, made of steel, high-density polyethylene, or
other plastic of equal or greater abrasion resistance.
What are the requirements for the strike-off bar used in this test method? -answer-Flat,
straight steel bar at least 1/8 by 3/4 by 12 in. [3 by 20 by 300 mm] or a 4.4 flat, straight
high-density polyethylene bar, or other plastic of equal or greater abrasion resistance, at
least 1/4 by 3/4 by 23 in [6 by 30 by 300 mm].
What is the approximate volume of the measuring cup used to add water to the air
meter, in relation to teh volume of the air meter bowl? -answer-1.00% +- 0.04%
What type of alcohol and concentration must be used in this test method? -answer-
Isopropyl, 70% by volume (65% by weight)
A mallet weighing ____ must be used to tap the sides of the bowl after rodding each
layer. -answer-1.25 +- 0.50 lb. (600 +- 200 g)
The sample of concrete used in this test method must be obtained in accordance with
what ASTM Standard? -answer-C172
The maximum size aggregate allowed in this test method is_____. -answer-1 1/2 in.
(37.5 mm)
If the concrete sample contains aggregate larger than that allowed for this test, the
sample must be _____. -answer-Wet sieved over a 1-in. (25-mm) sieve
When filling the bowl of the air meter, the concrete must be placed in _____ layers of
equal depth. -answer-2
What is the specified number of strokes required when rodding each layer of concrete? -
answer-25
It is necessary to tap the sides of the bowl after each layer has been rodded. True or
False? -answer-True
The initial quantity of water and alcohol added to the air meter can be poured directly
into the neck of the top section of the air meter. True or False? -answer-False; the
funnel must be used