ACI Concrete Field Testing Technician
Grade 1 Exam-Graded A
Collecting a representative sample of concrete to be tested is as important
as executing the test methods to obtain - ANSWER-accurate results
This practice covers sampling from 4 types of equipment: - ANSWER-stationary,
paving, revolving truck, continuous
The elapsed time between obtaining the first and final portions of a composite
sample shall not exceed - ANSWER-15 minutes
Portions of a composite sample shall be thoroughly remixed before beginning
tests on the sample. True or False? - ANSWER-True
Start tests for slump, temperature, and air content within _____
after obtaining the final portion of the composite sample - ANSWER-5 minutes
Start molding specimens for strength tests within _______ after
fabricating the composite sample - ANSWER-15 minutes
The concrete sample must be protected from contamination and - ANSWER-
evaporation
the minimum size sample for making strength test specimens is - ANSWER-1 cubic foot
When sampling from a stationary mixer, the batch must be sampled at
____ or more regularly spaced intervals during discharge of the
middle portion of the batch. - ANSWER-two
When sampling from a paving mixer, obtain samples from at least ____
different portions of the pile and combine them into one composite sample
for test purposes - ANSWER-five
When sampling from a revolving truck mixer, sample the concrete by collecting
____ or more portions take at regularly spaced intervals during
discharge of the middle portion of the batch. - ANSWER-two
Concrete samples from a truck mixer must be obtained before any water or
admixtures are added to the mixer at the job site. True or False - ANSWER-false
, When the concrete contains aggregate larger than that permitted for a particular
test method, the sample of concrete must be ________ before making the test -
ANSWER-wet screened
What must occur before a sample of concrete can be taken from a revolving drum
mixer? - ANSWER-all water and admixtures must be added to the mixer
When sampling from a stationary or revolving drum mixer, what is collected and when is
it taken during discharge? - ANSWER-- in two or more portions of concrete
- at regularly spaced intervals
- from the middle of the batch
how are the sample portions obtained from the discharge stream of a stationary or
revolving drum mixer? - ANSWER-- repeatedly pass a receptacle through the entire
discharge stream
- completely divert the discharge stream into a sample container
Describe the procedure for collecting a sample from a paving mixer - ANSWER--
discharge the contents of the paving mixer
- obtain the samples from at least 5 different portions of the pile
After the final rodding, the sides of the slump mold should be tapped lightly
with the tamping rod. True or False? - ANSWER-false
When raising the slump mold, it should not be rotated or twisted. True or
False? - ANSWER-true
How much time is allowed for lifting the slump mold? - ANSWER-5 +/- 2 seconds (3-7
seconds)
The measurement for slump is made from the top of the mold to what point
of the concrete specimen? - ANSWER-the displaced original center of the top surface of
the specimen
The slump of the concrete is measured and reported to the nearest ____ - ANSWER-
1/4"
How much time is allowed to conduct the slump test from beginning to
completion? - ANSWER-2.5 minutes
The length of the tamping rod used in this test method is _____ - ANSWER-at least 4"
taller than the height of the measure but no more than 24" in overall length
What is the required shape of the tamping end of the rod? - ANSWER-rounded to a
hemispherical tip
Grade 1 Exam-Graded A
Collecting a representative sample of concrete to be tested is as important
as executing the test methods to obtain - ANSWER-accurate results
This practice covers sampling from 4 types of equipment: - ANSWER-stationary,
paving, revolving truck, continuous
The elapsed time between obtaining the first and final portions of a composite
sample shall not exceed - ANSWER-15 minutes
Portions of a composite sample shall be thoroughly remixed before beginning
tests on the sample. True or False? - ANSWER-True
Start tests for slump, temperature, and air content within _____
after obtaining the final portion of the composite sample - ANSWER-5 minutes
Start molding specimens for strength tests within _______ after
fabricating the composite sample - ANSWER-15 minutes
The concrete sample must be protected from contamination and - ANSWER-
evaporation
the minimum size sample for making strength test specimens is - ANSWER-1 cubic foot
When sampling from a stationary mixer, the batch must be sampled at
____ or more regularly spaced intervals during discharge of the
middle portion of the batch. - ANSWER-two
When sampling from a paving mixer, obtain samples from at least ____
different portions of the pile and combine them into one composite sample
for test purposes - ANSWER-five
When sampling from a revolving truck mixer, sample the concrete by collecting
____ or more portions take at regularly spaced intervals during
discharge of the middle portion of the batch. - ANSWER-two
Concrete samples from a truck mixer must be obtained before any water or
admixtures are added to the mixer at the job site. True or False - ANSWER-false
, When the concrete contains aggregate larger than that permitted for a particular
test method, the sample of concrete must be ________ before making the test -
ANSWER-wet screened
What must occur before a sample of concrete can be taken from a revolving drum
mixer? - ANSWER-all water and admixtures must be added to the mixer
When sampling from a stationary or revolving drum mixer, what is collected and when is
it taken during discharge? - ANSWER-- in two or more portions of concrete
- at regularly spaced intervals
- from the middle of the batch
how are the sample portions obtained from the discharge stream of a stationary or
revolving drum mixer? - ANSWER-- repeatedly pass a receptacle through the entire
discharge stream
- completely divert the discharge stream into a sample container
Describe the procedure for collecting a sample from a paving mixer - ANSWER--
discharge the contents of the paving mixer
- obtain the samples from at least 5 different portions of the pile
After the final rodding, the sides of the slump mold should be tapped lightly
with the tamping rod. True or False? - ANSWER-false
When raising the slump mold, it should not be rotated or twisted. True or
False? - ANSWER-true
How much time is allowed for lifting the slump mold? - ANSWER-5 +/- 2 seconds (3-7
seconds)
The measurement for slump is made from the top of the mold to what point
of the concrete specimen? - ANSWER-the displaced original center of the top surface of
the specimen
The slump of the concrete is measured and reported to the nearest ____ - ANSWER-
1/4"
How much time is allowed to conduct the slump test from beginning to
completion? - ANSWER-2.5 minutes
The length of the tamping rod used in this test method is _____ - ANSWER-at least 4"
taller than the height of the measure but no more than 24" in overall length
What is the required shape of the tamping end of the rod? - ANSWER-rounded to a
hemispherical tip
