ACI Concrete Field Testing Technician- Grade I Study online at quizlet.com/_444cz 1.
A 6 by 12 in [150 mm by 300 mm] cylinder mold can be used for concrete containing aggregate with particles not exceeding _____ in size, without the need for wet sieving the concrete.: 2 in. [50 mm]
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measure before adding another layer of concrete?: Tap the sides of the measure smartly 10 to 15 times with the mallet 7.
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The diameter of the tamping rod used in the test method
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The direct reading of the final liquid level in the neck of
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During transportation, test specimens must be
is _____.: 5/8 in. [16 mm] the air meter, is estimated to teh nearest _____.: 0.25% protected from damage due to _____, _____, and _____.: Jarring, freezing temperatures, moisture loss
After the temperature of the concrete is read, what is required?: Reporting of temperature
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Each layer should fill approximately _____ the volume
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Field Curing is the curing method used when test
Air meter bowls used for this test must conform to ASTM _____ and be calibrated for volumee according to ASTM _____.: C231, C29
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of the mold.: One-third specimens are to be used for __________.: 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
The approximate concrete depth (in verticle distance) after placing the first layer is _____, and the second layer is _____.: 2 5/8 in. [70 mm], 6 1/8 in. [160 mm]
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ASTM Method gives standardized requirements for _____, _____, _____, and _____, of test specimens.: Making, curing, protecting, transporting
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The composite sample for a paving mixer must represent a minimum of _____ different portions of the batch of concrete taken from the pile after discharge.: 5
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Concrete mixtures with specified strengths of 6000 psi [40 MPa] or greater shall have an initial curing temperature between __________.: 68 and 78 degrees F [20 and 26 C]
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The concrete sample must be obtained in accodance with what ASTM method?: C172
For use in the slump test, the end or both ends of the tamping rod must be _____.: Rounded to a hemispherical tip
obtained from the _____ portion of the batch.: Middle 16.
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 _____.: 5/8 +- 1/16 in [16 mm +- 2 mm]
A composite sample of concrete is required even if the
The composite samples from a truck mixer must be
For concrete with a slump of less than 1 in. [25 mm], the test specimens must be consolidated by _____.: Vibration
only purpose for obtaining the sample is to determine temperature. True of False?: False 15.
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?: 25
At the end of the procedure, the air meter is _____.: Disassembled and its contents examined
13.
Cylinders that are to be field cured are stored __________ and protected __________.: 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
After the final rodding, the sides of the slump mold should should be tapped lightly with the tamping rod. True or False?: False
Cylinders made for the purpose of determining when a structure may be put into service shall be removed from the mold __________.: At the time of the removal of formwork
After molding test specimens, you should wait two hours
After rodding each layer, what should be done to the
The container for obtaining the concrete sample used in this procedure can be a _____, _____, or _____.: Metal pan, wheelbarrow, flat, clean nonabsorbent mixing board
before moving them to the location of initial storage. True or False?: False; the specimens must be moved immediately 6.
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?: False
After consolidation of the final layer, an excess of concrete ____ above the top of the measure is considered optimum.: 1/8 in. [3 mm]
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After completing the strike-off procedure, what must be done before weighing the measure and sample?: Clean off any excess concrete
The concrete sample must be protected from contamination and _____.: Rapid evaporation
According to ASTM C1064, what is one reason to take the temperature of concrete?: Verify conformance to a specified requirement for temperature of concrete
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The height of the slump mold is _____.: 12 in. [300 mm]
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How deep should the tamping rod penetrate into each layer?: 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]
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How long must the temperature measuring device
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remain in the freshly mixed concrete?: At least 2 minutes but not more than 5 minutes 35.
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+- 2 seconds How much time is allowed to conduct the slump test
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If less than 2.5 pints of alcohol are used, the air content
from beginning to completion?: 2 1/2 minutes is always indicated by the inal meter reading. True or False?: False, if the air content is more than 9%, the number of calibrated cups of water introduced into the meter to bring the liquid level within the graduated range must be added If more than 2.5 pints of alcohol are used, the final
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The interior surface of the slump mold is allowed to
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It is necessary to tap the sides of the bowl after each
have minor irregularities. True or False?: False layer has been rodded. True or False?: True 56.
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If the concrete contains aggregate larger than the
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specified in ASTM C1064. True of False?: False 62.
mold to what point of the concrete specimen?: The displaced original center of the top surface of the specimen Measures other than air meter bowls used for this test
standard 4 by 8 in. [100 mm by 200 mm] cylinder mold must be filled in _____ equal layers.: 2
64.
The minimum frequency of an internal vibrator used in
must conform to ASTM _____.: C29
If the concrete sample contains aggregate larger than
this procedure is _____.: 9000 vibrations per minute [150 Hz] 65.
The minimum size sample for making strength test
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The mold for making the slump test is in the shape of
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The molding of strength test specimens shall begin
If the concrete sample is to be consolidated by rodding,
specimens is _____.: 28 L (1ft^3)
If the concrete sample is to be consolidated by vibration, the measure is filled in _____ layers.: 2 equal
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_____.: The frustum of a cone
If vibration is the method of consolidation, the measure
within _____ minutes after fabricating the composite sample.: 15
must be filled in _____ approximately equal layers.: 2 50.
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?: Remove a representative portion of the excess concrete with a trowel or scoop
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The measurement for slump is made from the top of the
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the measure is filled in _____ layers.: 3 equal 48.
A maximum temperature of freshly mixed concrete is
If the concrete is to be consolidated by vibration, a
that allowed for this test, the sample must be _____.: Wet sieved over a 1-in. (25-mm) sieve 47.
The maximum size aggregate allowed in this test method is_____.: 1 1/2 in. (37.5 mm)
maximum allowed for this test, the sample must be _____.: Wet sieved over a 1 1/2 in. (37.5 mm) sieve 45.
The maximum size aggregate allowed for this test method is _____.: 50 mm (2 in.)
If the air content is greater than the 9% range of the meter, _____.: Calibrated cups of water are added to ring the liquid level within the graduated range
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.: 5
If rodding is the method of consolidation being used, the measure must be filled in how many layers?: 3
The maximum allowable time between obtaining the first and final portions of a composite sample is _____ minutes.: 15
If portions of undisturbed concrete are found in the air meter at the end of the test, _____.: The test is invalid
A mallet weighing ____ must be used to tap the sides of the bowl after rodding each layer.: 1.25 +- 0.50 lb. (600 +200 g)
meter reading is always adjusted using _____.: A correction factor 41.
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?: False; the funnel must be used
How much time is allowed for lifting the slump mold?: 5
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How many times does the rolling operation occur?: A minimum of 2, a minimum of 3
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penetrate each layer?: Rod bottom layer to full depth; rod second and final layer penetrating the previous layer about 25 mm (1 in.)
How long should the air meter be inverted and agitated?: No more than five seconds at a time, but must be repeated for a minimum of 45 seconds to free concrete from the base
In rodding the sample, how deep should the rod
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element must be at least _____ but not greater than _____.: 0.75 in. [19 mm], 1.50 in. [38 mm] 69.
In order for an initial meter reading to be valid, the meter must not be leaking, the liquid level must stabilize within 6 minutes, and the foam on the surface of the liquid must not be greater than 2 full percent divisions. True or False?: True
The outside diameter or side dimension of the vibrating
A plastic container can be used for the measure in this method. True or False?: False, measure must be steel or another suitable metal
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Portions of a composite sample shall be thoroughly remixed bfore beginning tests on the sample. True of False?: True
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The pressure method of determining air content can be
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The temperature measuring device shall be calibrated
used on concrete containing _____ _____ aggregate.: Relatively Dense 72.
The pressure method of determining air content cannot
_____, or whenever there is a question of _____.: Annually, accuracy 91.
The temperature measuring device shall have a capacity
be used on concrete containing the following types of aggregates, _____, _____, _____.: Lightweight, aircooled blast furnace slag, or aggregates of high porosity 73.
Prior to lifting the mold, concrete must be removed from
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The sample of concrete for use in making the slump test
of measuring temperature of freshly mixed concrete to +- _____ degrees F [+- _____ C] throughout a range of _____.: 1 degree F [0.5 C], 30 degrees F to 120 F [0 C to 50 C] 92.
The temperature of concrete is reported to the nearest
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The temperature of concrete may be measured in a wall
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The temperature of concrete may be measured in a
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This method covers sampling from four types of
_____.: The area surrounding the base of the mold must be obained in accordance with ASTM Standard _____.: C172, Standard Practice for Sampling Freshly Mixed Concrete 75.
The sample of concrete used for temperature
_____ degrees F [_____ C]: 1 degree F [0.5 C] form. True of False: True wheelbarrow. True or False?: True
determination must be rodded 25 times. True or False?: False 76.
The sample of concrete used for this test is to be obtained in accordance with what ASTM Standard?: C172
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mixtures which are _____, _____, _____, and _____.: Stationary mixers, paving mixers, revolving drum mixers, and open top mixers
The sample of concrete used in molding test specimens
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Transportation time shall not exceed _____.: 4h
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Up to 48 hours after molding, test specimens that are to be standard cured shall be stored in a temperature range between _____ to _____.: 60 and 70 degrees F [16 and 27 C]
must be obtained in accordance with what ASTM Standard?: C172 78.
The sample of concrete used in this test method must be
98.
Upon completion of initial curing, the test specimens
obtained in accordance with what ASTM Standard?: C172 79.
Sampling by this method is required when tests are to be made to determine _____ with specification requirements.: Compliance
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may be left in their molds and sealed in plastic bags. True or False?: False; specimens are to be demoled and placed in water storage tanks or moist rooms with free water at a temperature of 73.5 +- 3.5 degrees F [23.0 +- 2.0 C] 99.
Upon final filling of the air meter with water, what part
The sensor of the temperature measuring device shall be submerged a minimum of _____ in. [_____mm] into the freshly mixed concrete.: 3 in. [75 mm]
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The slump mold is filled in _____ layers.: 3
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The slump mold should be in a dry condition before
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The slump of the concrete is measured and reported to
of the liquid level should be adjusted to teh zero mark on the meter?: Bottom of the meniscus 100.
the slump of concrete exceeds _____.: 75 mm (3 in.) 101.
beginning the test. True or False?: False the nearest _____.: 1/4 in. [5 mm] 84.
The slump test is applicable to plastic concrete with a
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Specimens shall not be transported until _____ after
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Standard Curing is the curing method used when test
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The supporting surface on which specimens are stored The surface on which the slump mold will be placed must be _____.: Flat, level, moist, nonabsorbent, and free of vibration
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The temperature and moisture environment for field cured cylinders must be __________.: The same as the structural work
What are the requirements for the strike-off bar used in this test method?: 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].
shall be level within _____.: 1/4 in. per ft. [20 mm per m] 88.
What are the required characteristics of the tamping rod used in this test method?: Round, straight steel rod, with a 16 mm [5/8 in.] +- 2 mm [1/16 in.] diameter, length at least 100 mm [4 in.] greater than the depth of the measuring bowl, but not greater than 600 mm [24 in.] in overall length, with the tamping end rounded to a hemispherical tip of the same diameter as the rod.
final set.: 8h
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The volumetric method of determining air content of concrete can be used on concrete containing what types of aggregate?: All types of aggregate
maximum size aggregate of _____.: 1.5 in. [37.5 mm]
specimens are to be used for _________.: Acceptance testing for specified strength, checking the adequacy of mixture proportions for strength, quality control
Vibration of the concrete sample is not allowed when
104.
What are the requirements for the tamping rod used in the test method?: 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, highdensity polyethylene, or other plastic of equal or greater abrasion resistance.
105.
What is the approximate volume of the measuring cup
124.
used to add water to the air meter, in relation to teh volume of the air meter bowl?: 1.00% +- 0.04% 106.
What is the minimum allowable capacity of the
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measuring bowl used in this test method?: 6 L (0.20 ft^3) 107.
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What is the required shape of the tamping end of the
128.
What is the specified number of roddings for each layer?: 25
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What must be done if the concrete drops below the top of the slump mold while the top layer is being rodded?: Add additional concrete to keep an excess of concrete above the top of the mold at all times
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What must be done to the sample container prior to
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What type of alcohol and concentration must be used in this test method?: Isopropyl, 70% by volume (65% by weight)
When strenght specimens are to be made, what three other tests must be made?: Slump, air content, temperature
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When the concrete contains aggregate larger than allowed for the slump test, the large aggregate must be _____.: Removed by wet sieving the sample over 1.5 in. [37.5 mm] sieve
139.
When the concrete contains aggregate larger than that permitted for a particular test method, the sample of concrete must be _____ _____ before making the test.: Wet sieved
What tools may be used to strike off the top surface of the concrete following consolidation of the final layer?: A strike-off bar; a metal, glass, or acrylic plate
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: 2
sampling the concrete?: Dampen (with water) 122.
When sampling from a revolving drum truck mixer, concrete must be sampled at a minimum of _____ regularly spaced intervals during discharge of the middle portion of this batch.: 2
What must be done to the concrete surrounding the temperature measuring device after the device is submerged in the fresh concrete.: Gently press the concrete around the temperature measuring device at the surface of the concrete
When rodding the middle and the top layers, the tamping rod should penetrate into the layer below approximately _____.: 1 in. [25 mm]
What must be done if there is an excessive amount of concrete in measure following consolidation of the final layer?: Remove a representative quantity of concrete with the scoop or trowel before the strike off
120.
134.
What must be done if there is a slight deficiency in the quantity of concrete in the measure of consolidation of final layer?: Add a quantity of representative concrete before strike off
When rodding the concrete sample, what is the specified number of strokes required for each layer?: 25
slump is less than 1 in. (25 mm]?: Vibration 117.
When rodding the bottom layer, the tamping rod must be _____ to uniformly distribute the strokes.: Slightly inclined
What method of consolidation must be used when the What method of consolidation must be used when the
When rodding each upper layer of concrete in a cylinder, the tamping rod should penetrate into the underlying layer by about _____.: 1 in. [25 mm]
slump is greater than 3 in. [75 mm]?: Rodding 116.
When rodding a standard 6 by 12 in [150 mm by 300 mm] cylinder, each layer must be rodded _____ times.: 25
What is the specified weight of the mallet used on measures that are 0.5 ft^3 [14 L] or smaller?: 1.25 +- 0.50 lb. [600 +- 200 g]
When raising the slump mold, it should not be rotated or twisted, True or False?: True
What is the specified size of the mallet required for this test method when the measuring bowl has the capacity of 14 L [0.5 ft^3] or less?: 0.60 +- 0.25 kg [1.25 +- 0.50 lb.]
114.
129.
What is the specified number of strokes required when rodding each layer of concrete?: 25
When large amounts of alcohol are used, the direct reading will tend to indicate a _____ air content.: Higher
rod?: Rounded to a hemispherical tip 111.
When internal vibration is used to consolidate a standard flexural strength test specimen, the technician should insert the bibrator at intervals not exceeding _____ along the center line of the beam.: 6 in. [150 mm]
What is the required minimum frequency of the vibrator used in this test method?: 7000 vibrations per minute
110.
When filling the bowl of the air meter, the concrete must be placed in _____ layers of equal depth.: 2
What is the minimum thickness of a metal strike-off plate?: 1/4 in. [6 mm]
When consolidating the concrete by vibration, how many times should the vibrator be inserted into each layer?: Three (3)
What is the minimum thickness for a glass or acrylic strike-off plate?: 1/2 in. [12 mm]
When consolidating a flexural strength test specimen by rodding, rod one stroke for each _____ of top surface area.: 2 in.^2 [14 cm^2]
140.
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.: 2
141.
Why is the isopropyl alcohol added to the meter?: To dispel any foam that may be on the surface of the water
