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ACI CERTIFICATION- CONCRETE FIELD-TESTING TECHNICIAN GRADE 1 CP-1 (12)
EXAM QUESTIONS WITH CORRECT ANSWERS
"The temperature measuring device shall have a capacity of measuring temperature of freshly
mixed concrete to ± ______ °F throughout a range of ____________. - CORRECT ANSWER 1
degree, 30 degrees to 120 degrees" "The temperature measuring device shall be calibrated ______ , or whenever there is a question
of ______. - CORRECT ANSWER Annually, accuracy"
"The temperature of concrete may be measured in a wheelbarrow. True or False? - CORRECT
ANSWER True"
"The temperature of concrete may be measured in a wall form. True or False? - CORRECT
ANSWER True"
"What must be done to the sample container prior to sampling the concrete? - CORRECT
ANSWER Dampen with water"
"The temperature of the concrete is reported to the nearest ______ °F - CORRECT ANSWER 1
degree"
"A maximum temperature of freshly mixed concrete is specified in ASTM C1064. True or False? -
CORRECT ANSWER False"
"ASTM C172 - CORRECT ANSWER Standard Practice for Sampling Freshly Mixed Concrete"
"Portions of a composite sample shall be thoroughly remixed before beginning tests on the
sample. True or False? - CORRECT ANSWER True"
"The maximum elapsed time allowed between obtaining the final portion of the composite
sample and beginning the tests for slump, temperature, and air content is _____ minutes. -
CORRECT ANSWER 5"
"The molding of strength test specimens shall begin within _____ minutes after fabricating the composite
sample. - CORRECT ANSWER 15"
"The concrete sample must be protected from contamination and _____. - CORRECT ANSWER
Rapid evaporation"
"The minimum size sample for making strength test specimens is _____. - CORRECT ANSWER
1 cubic foot" "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? - CORRECT ANSWER False"
"The composite sample from a truck mixer must be obtained from the _____ portion of the batch.
- CORRECT ANSWER middle"
"When the concrete contains aggregate larger than that permitted for a particular test method,
the sample of concrete must be _____ _____ before making the test. - CORRECT ANSWER wet
sieved" "Describe the procedure for collecting a sample of pavement concrete deposited on grade. (Oral
Exam) - CORRECT ANSWER Discharge the contents of the paving mixer, Obtain samples from
at least five different portions of the pile" "What is the minimum size for a sample when strength test specimens are to be molded? (Oral
Exam) - CORRECT ANSWER 1 cubic foot (28 L)"
"What is the maximum allowable time between obtaining the first and final portions of the
composite sample? (Oral Exam) - CORRECT ANSWER 15 min."
"What is required after the concrete sample has been transported to the place where tests are to
be performed? (Oral Exam) - CORRECT ANSWER Combine and remix the sample with a
shovel" "What should be done if the concrete contains aggregate larger than is appropriate for the size of
the molds or equipment being used? (Oral Exam) - CORRECT ANSWER Wet sieving"
"When raising the slump mold, it should not be rotated or twisted. True or False? - CORRECT
ANSWER True"
"How much time is allowed for lifting the slump mold? - CORRECT ANSWER 5 ± 2 seconds"
"The measurement for slump is made from the top of the mold to what point of the concrete
specimen? - CORRECT ANSWER The displaced original center of the top surface of the
specimen"
"The slump of the concrete is measured and reported to the nearest _____. - CORRECT
ANSWER ¼ in. [5 mm]"
"How much time is allowed to conduct the slump test from beginning to completion? -
CORRECT ANSWER 2½ minutes"
"What is the minimum thickness of a metal strike-off plate? - CORRECT ANSWER ¼ in. [6 mm]"
"What is the minimum thickness for a glass or acrylic strike-off plate? - CORRECT ANSWER ½
in. [12 mm]"
"What is the specified weight of the mallet used on measures that are 0.5 ft3 [14 L] or smaller? -
CORRECT ANSWER 1.25 ± 0.50 lb. [600 ± 200 g]"
"Measures other than air meter bowls used for this test must conform to ASTM _____. -
CORRECT ANSWER C29"
"Air meter bowls used for this test must conform to ASTM _____ and be calibrated for volume according
to ASTM _____. - CORRECT ANSWER C231, C29"
"The concrete sample must be obtained in accordance with what ASTM method? - CORRECT
ANSWER C172"
"What method of consolidation must be used when the slump is greater than 3 in. [75 mm]? -
CORRECT ANSWER Rodding"
"What method of consolidation must be used when the slump is less than 1 in. [25 mm]? -
CORRECT ANSWER Vibration"
"If rodding is the method of consolidation being used, the measure must be filled in how many
layers? - CORRECT ANSWER 3"
"For a measure of 0.5 ft3 [14 L], what is the required number of strokes of the tamping rod for consolidation
of each layer? - CORRECT ANSWER 25"
"After completing the strike-off procedure, what must be done before weighing the measure and
sample? - CORRECT ANSWER Clean off any excess concrete"
"Density (Unit Weight) Calculation Known: Volume of measure = 0.504 ft3 [14.27 L or 0.01427 m3] Mass of empty measure = 19.6 lb [8.89 kg] The procedures of Method C138 are followed, and the mass of the measure plus the concrete is
found to be 92.1 lb [41.78 kg]. Calculate the density of the concrete in lb/ft3 [kg/m3]. - CORRECT
ANSWER 143.9 lb/ft3 [2305 kg/m3]"
"Air Content Calculation Your air meter has been damaged in transit to the job site. You do, however, possess the theoretical density that was determined in the lab; it is 151.4 lb/ft3 (2425 kg/m3). Using the
density calculated in Question 21, calculate the air content of the batch (in percentage). -
CORRECT ANSWER 5.0% = [(151.4 lb/ft3 - 143.9 lb/ft3) / 151.4 lb/ft3] × 100
5.0% = [(2425 kg/m3 - 2305 kg/m3) / 2425 kg/m3] × 100"
"ASTM C231 - CORRECT ANSWER
StandardTestMethodforAirContentofFreshlyMixedConcretebythePressureMethod" "The pressure method of determining air content can be used on concrete containing _____
_____ aggregate. - CORRECT ANSWER Relatively Dense"
"The pressure method of determining air content cannot be used on concrete containing the
following types of aggregate: _____, _____, _____. - CORRECT ANSWER Lightweight, air-
cooled blast furnace slag, or aggregates of high porosity"
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? - CORRECT
ANSWER Flat, straight steel bar at least 1/8 by 3/4 by 12 in. [3 by 20 by 300 mm] or a flat,
straight high-density polyethylene bar, or other plastic of equal or greater abrasion resistance, at least 1/4 by 3/4 by 12 in. [6 by 20 by 300 mm]." "What is the approximate volume of the measuring cup used to add water to the air meter, in
relation to the volume of the air meter bowl? - CORRECT ANSWER 1.00% ± 0.04%"
"What type of alcohol and concentration must be used in this test method? - CORRECT
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. -
CORRECT 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? - CORRECT ANSWER C172"
"The maximum size aggregate allowed in this test method is _____. - CORRECT ANSWER 1½
in. (37.5 mm)" "If the concrete sample contains aggregate larger than that allowed for this test, the sample must
be _____. - CORRECT ANSWER Wet sieved over a 1-in. (25-mm) sieve"
"When filling the measuring bowl of the air meter, the concrete must be placed in _____ layers of
equal depth. - CORRECT ANSWER 2"
"What is the specified number of strokes required when rodding each layer of concrete? -
CORRECT ANSWER 25"
"It is necessary to tap the sides of the measuring bowl after each layer has been rodded. True or
False? - CORRECT ANSWER True"
"Why is the isopropyl alcohol added to the meter? - CORRECT ANSWER To dispel any foam
that may be on the surface of the water"
"The direct reading of the final liquid level in the neck of the air meter, is estimated to the nearest
_____. - CORRECT ANSWER 0.25%"
"If the air content is greater than the 9% range of the meter, __________. - CORRECT ANSWER
Calibrated cups of water are added to bring the liquid level within the graduated range" "If more than 1.25 L [2.5 pt] of alcohol are used, the final meter reading is always adjusted using
_______. - CORRECT ANSWER A correction factor"
"When large amounts of alcohol are used, the direct reading will tend to indicate a __________
air content. - CORRECT ANSWER Higher"
"At the end of the procedure, the air meter is _______. - CORRECT ANSWER Disassembled and
its contents examined" "If portions of undisturbed concrete are found in the air meter at the end of the test, _________.
CORRECT ANSWER The test is invalid"
"ASTM C31 - CORRECT ANSWER Standard Practice for Making and Curing
Concrete Test Specimens in the Field" "ASTM Method C31 gives standardized requirements for _____, _____, _____, and _____, of test
specimens. - CORRECT ANSWER Making, curing, protecting, transporting"
"For cylinders with a diameter of 6 in. [150 mm] or greater, the tamping rod must be a round,
straight steel rod with a diameter of _____. - CORRECT ANSWER 5/8 ± 1/16 in. [16 mm ± 2
mm]"
"The minimum frequency of an internal vibrator used in this procedure is _____. - CORRECT
ANSWER 9000 vibrations per minute [150 Hz]"
"The container for obtaining the concrete sample used in this procedure can be a _____, _____,
or _____. - CORRECT ANSWER Metal pan, wheelbarrow, flat, clean nonabsorbent mixing
board"
"Upon completion of initial curing, the test specimens may be left in their molds and sealed in
plastic bags. True or False? - CORRECT ANSWER False; specimens are to be demolded and
placed in water storage tanks or moist rooms with free water at a temperature of 73.5 ± 3.5 °F [23.0 ± 2.0 °C]" "During transportation, test specimens must be protected from damage due to _____, _____,
and _____. - CORRECT ANSWER Jarring, freezing temperatures, moisture loss"
"Specimens shall not be transported until _______ after final set. - CORRECT ANSWER 8h"
"Transportation time shall not exceed _____________. - CORRECT ANSWER 4h"
"Standard Curing is the curing method used when test specimens are to be used for
______________. - CORRECT ANSWER Acceptance testing for specified strength, checking
the adequacy of mixture proportions for strength, quality control" "Field Curing is the curing method used when test specimens are to be used for
______________. - CORRECT ANSWER Determination of whether the structure is capable of
being put into service; Comparison with standard cured specimens test results or with results from various in-place test methods; Adequacy of curing and protection of concrete in the Structure, or Form or shoring removal time requirements" "Cylinders that are to be field cured are stored ___________________________ and protected
_______. - CORRECT ANSWER In or on the structure as near to the point of deposit of the
concrete represented as possible; In as near as possible the same way as the formed work" "The temperature and moisture environment for field cured cylinders must be _____________________________________________________________________________.
- CORRECT ANSWER The same as the structural work"
"Cylinders made for the purpose of determining when a structure may be put into service shall be removed from the molds _________________________________________________________.
- CORRECT ANSWER At the time of the removal of formwork"
The temperature measuring device shall be capable of accurately measuring the temperature of
freshly mixed concrete to_____ throughout a range of ______ - CORRECT ANSWER 30
degrees, 120 degrees"
"A composite sample of concrete is required even if the only purpose for obtaining the sample is
to determine temperature. True or False? - CORRECT ANSWER False"
"A maximum temperature of freshly mixed concrete is specified in ASTM C1064. True of False? -
CORRECT ANSWER False"
"The concrete sample must be protected from contamination and _____ - CORRECT ANSWER
Rapid evaporation" "The composite sample from a truck mixer must be obtained from the _____ portion of the batch
- CORRECT ANSWER Middle"
"The slump test is applicable to plastic concrete with a maximum size aggregate of _____ -
CORRECT ANSWER 1 1/2 inches"
"The slump of the concrete is measured and reported to the nearest _____. - CORRECT
ANSWER quarter of an inch"
"How much time is allowed to conduct the slump test from beginning to completion? -
CORRECT ANSWER 2 1/2 minutes"
"The diameter of the tampering rod used in this test method is - CORRECT ANSWER 5/8 in +-
1/16 in"
"What is the required minimum frequency of the vibrator used in this test method? - CORRECT
ANSWER 9000 vibrations per minute (150 hz)"
"The outside diameter or side dimension of the vibrating element must be at least _____ but not
greater than _____. - CORRECT ANSWER .75 in and 1.50 in"
"A plastic container can be used for the measure in this method. True or False? - CORRECT
ANSWER False"
"What is the minimum thickness of a metal strike-off plate? - CORRECT ANSWER 1/4 in"
B. Yield per batch = 7.0 yd Y(yd3) = M/(Dx27= 27,300 lb/ (27x143.8) = 27,300 lb/ 3882.6 = 7.031 yd C. Yield per batch = 5.4 m Y(m3) = M/D = 12,383 / 2305 = 5. D. Yield per cubic yard = 27.1 ft Y(ft3/yd3) = Yf/Yd = 189.8 ft / 7 yd3 = 27.10 ft3" "Relative Yield Calculation: Using the information given and calculated in Question 22, calculate the relative yield for the
batch of concrete. - CORRECT ANSWER 1.
A. 189.8/ 189 = 1
B. 7 / 7 = 1
C. 5.4/ 5.4 = 1
D. 27.1/ 27 = 1"
"Air Content Calculation: Your air meter has been damaged in transit to the job site. You do, however, possess the theoretical density that was determined in the lab; it is 151.4 lb/ft3 (2425 kg/m3). Using the
density calculated in Question 21, calculate the air content of the batch (in percentage). -
CORRECT ANSWER Air Content Using Density in lb/ft
5.0% = [(151.4-143.8) / 151.4] x 100 Air Content Using Density in kg/m 5.0% = [( 2426- 2305) / 2426] x 100" "The pressure method of determining air content can be used on concrete containing______
aggregate - CORRECT ANSWER relatively dense"
"The pressure method of determining air content cannot be used on concrete containing the
following types of aggregates, _____, _____, _____. - CORRECT ANSWER lightweight, air-
cooled blast furnace slag, aggregates of high porosity" "The sample of concrete used in this test method (air) must be obtained in accordance with what
ASTM Standard? - CORRECT ANSWER C172/C172M"
"The maximum size aggregate for this test method is - CORRECT ANSWER 2 in"
"If the concrete contains aggregate larger than the maximum allowed for this test, the sample
must be _____. - CORRECT ANSWER Wet sieved over a 1-1/2 in sieve"
"Vibration of the concrete sample is not allowed when the slump of concrete exceeds _____. -
CORRECT ANSWER 3 in"
"What tools may be used to strike off the top surface of the concrete following consolidation of
the final layer? - CORRECT 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
following consolidation of the final layer? - CORRECT ANSWER Add a quantity of
representative concrete before strike off" "What is the approximate volume of the measuring cup used to add water to the air meter, in
relation to the column of the air meter bowl? - CORRECT ANSWER 1.00 +- .04%"
"What type of alcohol and concentration must be used - CORRECT 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. -
CORRECT ANSWER 1.25 +- .50lb"
"The sample of concrete used in this test method must be obtained in accordance with what
ASTM Standard (air content of freshly mixed concrete by volumetric measure)? - CORRECT
ANSWER C172/C172M"
"The maximum size aggregate allowed for this test method (C173) is _____. - CORRECT
ANSWER 1-1/2 in"
"If the concrete sample contains aggregate larger than that allowed for this test (C173), the
sample must be _____. - CORRECT ANSWER Wet sieved over a 1 in sieve"
"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? - CORRECT ANSWER False"
"For cylinders with a diameter of 6 in. [150 mm] or greater, the tamping rod must be a round,
straight steel rod with a diameter of _____. - CORRECT ANSWER 5/8 +- 1/16 inch"
"The container for obtaining the concrete sample used in this procedure can be a _____, _____,
or _____. - CORRECT ANSWER metal pan, wheelbarrow, flat clean nonabsorbent mix board"
"A 6 by 12 in. cylinder mold can be used for concrete containing aggregate with particles not
exceeding _______ in size , without the need for wet sieving the concrete. - CORRECT
ANSWER 50 mm [2 in]"
"The sample of concrete used in molding test specimens must be obtained in accordance with
what ASTM Standard? - CORRECT ANSWER C172"
"When strength specimens are to be made, what three other tests must be made? - CORRECT
ANSWER Slump, air content, and temp"
"The supporting surface on which specimens are stored shall be level within - CORRECT
ANSWER 20 mm"
"For concrete with a slump of less than 1 in. the test specimens must be consolidated by _____.
CORRECT ANSWER vibration"
"If the concrete is to be consolidated by vibration, a standard 4 by 8 in. cylinder mold must be
filled in _____ equal layers. - CORRECT ANSWER 2"
"When rodding a standard 6 by 12 in cylinder, each layer must be rodded _____ times. -
CORRECT ANSWER 25"
"When rodding each upper layer of concrete in a cylinder, the tamping rod should penetrate into
the underlying layer by about _____. - CORRECT ANSWER 25 mm [1 in]"
"When using an internal vibrator to consolidate a 6 by 12 in. [150 mm by 300 mm] compressive
strength test specimen, the vibrator must be inserted at _____ different points for each layer. -
CORRECT ANSWER 2"
"When consolidating a flexural strength test specimen by rodding, rod one stroke for each _____
of top surface area.. - CORRECT ANSWER 2 in"
"When internal vibration is used to consolidate a standard flexural strength test specimen, the technician should inset the vibrator at intervals not exceeding ______ along the center line of the
beam - CORRECT ANSWER 150 mm"
"Concrete mixtures with specified strengths of 6000 psi [40 MPa] or greater shall have an initial
curing temperature between __________. - CORRECT ANSWER 68 and 78 degrees"
"Up to 48 hours after molding, test specimens that are to be standard cured shall be stored in a
temperature range between _____ to _____. - CORRECT ANSWER 60 and 80 degrees"
"Upon completion of initial curing, the test specimens may be left in their molds are sealed in
plastic bags. True or False? - CORRECT ANSWER False"
"During transportation, test specimens must be protected from damage due to _____, and
______ - CORRECT ANSWER jarring, freezing temp, and moisture loss"
"Specimens shall not be transported until _____ after final set. - CORRECT ANSWER 8 hours"
"Transportation time shall not exceed ______ - CORRECT ANSWER 4 hours"
"Standard Curing is the curing method used when test specimens are to be used for _________.
CORRECT ANSWER Acceptance testing for specified strength, checking the adequacy of
mixture proportions for strength, and quality control"
"Field Curing is the curing method used when test specimens are to be used for __________. -
CORRECT ANSWER Determination of whether the structure is capable of being put into
service, comparison with standard cured specimens test results or with results from various in- place test methods, adequacy of curing and protection of concrete in the structure, and dorm or shoring removal time requirements"
"Cylinders that are to be field cured and stored ________ and protected ______ - CORRECT
ANSWER In or on the structure as near to the point of deposit of the concrete represented as
possible, in as near as possible the same way as the formed work."
"The temperature and moisture environment for field cured cylinders must be __________. -
CORRECT ANSWER the same as the structure work"
"What must occur before a sample of concrete can be taken from a revolving drum mixer? (Oral
Exam) - CORRECT ANSWER All of the water must be added to the mixer"
"Describe the different procedures that can be used to collect a sample of concrete from a
stationary or revolving drum mixer. (Oral Exam) - CORRECT ANSWER Repeatedly pass a
receptacle through the entire discharge stream, Completely divert the discharge stream into a sample container" "What are the required steps for collecting a sample of concrete from a stationary or revolving
drum mixer? (Oral Exam) - CORRECT ANSWER Collect two or more portions of concrete, Take
the portions at regularly spaced intervals, Take the portions from the middle of the batch" "Start the tests for slump, temperature, and air content within how many minutes after obtaining
the final portion of the composite sample? (Oral Exam) - CORRECT ANSWER 5 min."
"Start molding specimens for strength tests within how many minutes after fabricating the
composite sample? (Oral Exam) - CORRECT ANSWER 15 min."
"From what must the concrete sample be protected? (Oral Exam) - CORRECT ANSWER Sun,
wind, rapid evaporation, and contamination"
"ASTM C143 - CORRECT ANSWER Standard Test Method for Slump of Hydraulic-Cement
Concrete"
"The slump test is applicable to plastic concrete with a maximum size aggregate of _____. -
CORRECT ANSWER 1½ in."
"How deep should the tamping rod penetrate into each layer? - CORRECT ANSWER Rod each
layer throughout its depth; on the second and final layers, the rod should penetrate into the previous layer approximately 1 in. [25 mm]" "When rodding the bottom layer, the tamping rod must be _____ to uniformly distribute the
strokes. - CORRECT ANSWER Slightly inclined"
"What must be done if the concrete drops below the top of the slump mold while the top layer is
being rodded? - CORRECT ANSWER Add additional concrete to keep an excess of concrete
above the top of the mold at all times"
"Prior to lifting the mold, concrete must be removed from _______. - CORRECT ANSWER The
area surrounding the base of the mold"
"ASTM C138 - CORRECT ANSWER Standard Test Method for Density (Unit Weight),
Yield, and Air Content (Gravimetric) of Concrete"
"The diameter of the tamping rod used in this test method is _____. - CORRECT ANSWER ⅝ in.
[16 mm]"
"What is the required shape of the tamping end of the rod? - CORRECT ANSWER Rounded to a
hemispherical tip"
"What is the required minimum frequency of the vibrator used in this test method? - CORRECT
ANSWER 7000 vibrations per minute"
"The outside diameter or side dimension of the vibrating element must be at least _____ but not
greater than _____. - CORRECT ANSWER 0.75 in. [19 mm], 1.50 in. [38 mm]"
"A plastic container can be used for the measure in this method. True or False? - CORRECT
ANSWER False, measure must be steel or other suitable metal"
"When rodding the middle and the top layers, the tamping rod should penetrate into the layer
below approximately _____. - CORRECT ANSWER 1 in. [25 mm]"
"If vibration is the method of consolidation, the measure must be filled in _____ approximately
equal layers. - CORRECT 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? - CORRECT ANSWER Remove a representative portion of the
excess concrete with a trowel or scoop" "After consolidation of the final layer, an excess of concrete _____ above the top of the measure
is considered optimum. - CORRECT ANSWER ⅛ in. [3 mm]"
"Yield Calculations For a design batch of 7.0 yd3 [5.4 m3], the total mass of all materials batched was 27,300 lb [12,383 kg]. Using the density of the concrete as determined in Question 21, calculate: a) The yield per batch in ft b) The yield per batch in yd c) The yield in m
d) The yield per cubic yard in ft3/yd3 - CORRECT ANSWER a. Yield per batch = 189.7 ft
b. Yield per batch = 7.0 yd c. Yield per batch = 5.4 m
