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ASTM C172 outlines the sampling methods applicable to stationary, paving, and truck mixers,
and to agitating and non-agitating concrete transport equipment. ASTM C172 outlines the
sampling methods applicable to stationary, paving, and truck mixers, and to agitating and non-
agitating concrete transport equipment.
True
When the concrete incorporates large aggregate, the testing technician should wet-sieve the
sample before conducting unit weight tests for application in yield computations.
False
Samples must be collected before 10% or following 90% of the batch is released.
False
Samples smaller than 28L (1 cu.ft.) are allowed on routine air content, temperature, and slump
tests.
True
Tests for slump and air content must be started within ____________ after obtaining the final
portion of the composite sample.
5 Minutes
Start molding strength test specimens within ________ after fabricating the composite sample.
15 Minutes
How do you regulate the rate of discharge of the batch from the revolving truck drum mixer or
agitator?
By the rate of revolution of the drum
The mold is in the shape of a ___________________.
Frustum of a Cone
, The top diameter of a slump cone is ______ and the diameter at the base is ________.
4", 8"
While the technician is checking the slump of the concrete, there is a decided falling away or
shearing off of the concrete from one side of the sample. What should the technician do?
Disregard the test and retest on another portion of the sample
The mold is filled in three equal layers by volume, which makes the first third at _______, and
the second third at ________.
2 5/8, 6 1/8
The maximum size of aggregate allowed for ASTM C143 is _________.
1 ½"
When rodding the second and third layers, the rod should penetrate through the layer and into the
previous layer________.
1"
The slump of the concrete was determined to be 4 5/16" what should be recorded as the slump?
4 1/4"
What is the difference allowed by ACI when certifying an individual test using a plastic slump
cone vs. a metal slump cone?
.5"
The sides of the slump mold should be lightly tapped to consolidate the concrete in the mold.
False
When rodding the final lift, additional concrete must be added to keep excess concrete above the
top of the mold at all times.
True
ASTM C 1064 defines the maximum recommended temperature for concrete.
False
The temperature test method must be completed within _________ after obtaining the sample.
5 Minutes
Each temperature-measuring device should be calibrated ________, or whenever there is a
question of _________.
Annually, Accuracy