question

The sensor of the temperature measuring device shall be submerged a minimum of _____ in. [_____mm] into the freshly mixed concrete.

answer

3 in. [75 mm]

question

The temperature measuring device shall have a capacity of measuring temperature of freshly mixed concrete to +- _____ degrees F [+- _____ C] throughout a range of _____.

answer

1 degree F [0.5 C], 30 degrees F to 120 F [0 C to 50 C]

question

The temperature measuring device shall be calibrated _____, or whenever there is a question of _____.

answer

Annually, accuracy

question

The temperature of concrete may be measured in a wheelbarrow. True or False?

answer

True

question

The temperature of concrete may be measured in a wall form. True of False

answer

True

question

A composite sample of concrete is required even if the only purpose for obtaining the sample is to determine temperature. True of False?

answer

False

question

What must be done to the sample container prior to sampling the concrete?

answer

Dampen (with water)

question

What must be done to the concrete surrounding the temperature measuring device after the device is submerged in the fresh concrete.

answer

Gently press the concrete around the temperature measuring device at the surface of the concrete

question

How long must the temperature measuring device remain in the freshly mixed concrete?

answer

At least 2 minutes but not more than 5 minutes

question

After the temperature of the concrete is read, what is required?

answer

Reporting of temperature

question

The temperature of concrete is reported to the nearest _____ degrees F [_____ C]

answer

1 degree F [0.5 C]

question

According to ASTM C1064, what is one reason to take the temperature of concrete?

answer

Verify conformance to a specified requirement for temperature of concrete

question

A maximum temperature of freshly mixed concrete is specified in ASTM C1064. True of False?

answer

False

question

The sample of concrete used for temperature determination must be rodded 25 times. True or False?

answer

False

question

Sampling by this method is required when tests are to be made to determine _____ with specification requirements.

answer

Compliance

question

This method covers sampling from four types of mixtures which are _____, _____, _____, and _____.

answer

Stationary mixers, paving mixers, revolving drum mixers, and open top mixers

question

The maximum allowable time between obtaining the first and final portions of a composite sample is _____ minutes.

answer

15

question

Portions of a composite sample shall be thoroughly remixed bfore beginning tests on the sample. True of False?

answer

True

question

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.

answer

5

question

The molding of strength test specimens shall begin within _____ minutes after fabricating the composite sample.

answer

15

question

The concrete sample must be protected from contamination and _____.

answer

Rapid evaporation

question

The minimum size sample for making strength test specimens is _____.

answer

28 L (1ft^3)

question

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

2

question

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.

answer

5

question

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.

answer

2

question

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

question

The composite samples from a truck mixer must be obtained from the _____ portion of the batch.

answer

Middle

question

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 sieved

question

The slump test is applicable to plastic concrete with a maximum size aggregate of _____.

answer

1.5 in. [37.5 mm]

question

When the concrete contains aggregate larger than allowed for the slump test, the large aggregate must be _____.

answer

Removed by wet sieving the sample over 1.5 in. [37.5 mm] sieve

question

The mold for making the slump test is in the shape of _____.

answer

The frustum of a cone

question

The height of the slump mold is _____.

answer

12 in. [300 mm]

question

The interior surface of the slump mold is allowed to have minor irregularities. True or False?

answer

False

question

For use in the slump test, the end or both ends of the tamping rod must be _____.

answer

Rounded to a hemispherical tip

question

The sample of concrete for use in making the slump test must be obained in accordance with ASTM Standard _____.

answer

C172, Standard Practice for Sampling Freshly Mixed Concrete

question

The slump mold should be in a dry condition before beginning the test. True or False?

answer

False

question

The surface on which the slump mold will be placed must be _____.

answer

Flat, level, moist, nonabsorbent, and free of vibration

question

The slump mold is filled in _____ layers.

answer

3

question

Each layer should fill approximately _____ the volume of the mold.

answer

One-third

question

The approximate concrete depth (in verticle distance) after placing the first layer is _____, and the second layer is _____.

answer

2 5/8 in. [70 mm], 6 1/8 in. [160 mm]

question

What is the specified number of roddings for each layer?

answer

25

question

How deep should the tamping rod penetrate into each layer?

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]

question

When rodding the bottom layer, the tamping rod must be _____ to uniformly distribute the strokes.

answer

Slightly inclined

question

What must be done if the concrete drops below the top of the slump mold while the top layer is being rodded?

answer

Add additional concrete to keep an excess of concrete above the top of the mold at all times

question

Prior to lifting the mold, concrete must be removed from _____.

answer

The area surrounding the base of the mold

question

After the final rodding, the sides of the slump mold should should be tapped lightly with the tamping rod. True or False?

answer

False

question

When raising the slump mold, it should not be rotated or twisted, True or False?

answer

True

question

How much time is allowed for lifting the slump mold?

answer

5 +- 2 seconds

question

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

question

The slump of the concrete is measured and reported to the nearest _____.

answer

1/4 in. [5 mm]

question

How much time is allowed to conduct the slump test from beginning to completion?

answer

2 1/2 minutes

question

The diameter of the tamping rod used in the test method is _____.

answer

5/8 in. [16 mm]

question

What is the required shape of the tamping end of the rod?

answer

Rounded to a hemispherical tip

question

What is the required minimum frequency of the vibrator used in this test method?

answer

7000 vibrations per minute

question

The outside diameter or side dimension of the vibrating element must be at least _____ but not greater than _____.

answer

0.75 in. [19 mm], 1.50 in. [38 mm]

question

A plastic container can be used for the measure in this method. True or False?

answer

False, measure must be steel or another suitable metal

question

What is the minimum thickness of a metal strike-off plate?

answer

1/4 in. [6 mm]

question

What is the minimum thickness for a glass or acrylic strike-off plate?

answer

1/2 in. [12 mm]

question

What is the specified weight of the mallet used on measures that are 0.5 ft^3 [14 L] or smaller?

answer

1.25 +- 0.50 lb. [600 +- 200 g]

question

Measures other than air meter bowls used for this test must conform to ASTM _____.

answer

C29

question

Air meter bowls used for this test must conform to ASTM _____ and be calibrated for volumee according to ASTM _____.

answer

C231, C29

question

The concrete sample must be obtained in accodance with what ASTM method?

answer

C172

question

What method of consolidation must be used when the slump is greater than 3 in. [75 mm]?

answer

Rodding

question

What method of consolidation must be used when the slump is less than 1 in. (25 mm]?

answer

Vibration

question

If rodding is the method of consolidation being used, the measure must be filled in how many layers?

answer

3

question

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?

answer

25

question

When rodding the middle and the top layers, the tamping rod should penetrate into the layer below approximately _____.

answer

1 in. [25 mm]

question

If vibration is the method of consolidation, the measure must be filled in _____ approximately equal layers.

answer

2

question

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?

answer

Remove a representative portion of the excess concrete with a trowel or scoop

question

After consolidation of the final layer, an excess of concrete ____ above the top of the measure is considered optimum.

answer

1/8 in. [3 mm]

question

After completing the strike-off procedure, what must be done before weighing the measure and sample?

answer

Clean off any excess concrete

question

The pressure method of determining air content can be used on concrete containing _____ _____ aggregate.

answer

Relatively Dense

question

The pressure method of determining air content cannot be used on concrete containing the following types of aggregates, _____, _____, _____.

answer

Lightweight, air-cooled blast furnace slag, or aggregates of high porosity

question

What is the minimum allowable capacity of the measuring bowl used in this test method?

answer

6 L (0.20 ft^3)

question

What are the required characteristics of the tamping rod used in this test method?

answer

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.

question

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?

answer

0.60 +- 0.25 kg [1.25 +- 0.50 lb.]

question

The sample of concrete used for this test is to be obtained in accordance with what ASTM Standard?

answer

C172

question

The maximum size aggregate allowed for this test method is _____.

answer

50 mm (2 in.)

question

If the concrete contains aggregate larger than the maximum allowed for this test, the sample must be _____.

answer

Wet sieved over a 1 1/2 in. (37.5 mm) sieve

question

If the concrete sample is to be consolidated by rodding, the measure is filled in _____ layers.

answer

3 equal

question

If the concrete sample is to be consolidated by vibration, the measure is filled in _____ layers.

answer

2 equal

question

When rodding the concrete sample, what is the specified number of strokes required for each layer?

answer

25

question

Vibration of the concrete sample is not allowed when the slump of concrete exceeds _____.

answer

75 mm (3 in.)

question

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.)

question

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

question

When consolidating the concrete by vibration, how many times should the vibrator be inserted into each layer?

answer

Three (3)

question

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

question

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

question

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

question

The volumetric method of determining air content of concrete can be used on concrete containing what types of aggregate?

answer

All types of aggregate

question

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.

question

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].

question

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%

question

What type of alcohol and concentration must be used in this test method?

answer

Isopropyl, 70% by volume (65% by weight)

question

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)

question

The sample of concrete used in this test method must be obtained in accordance with what ASTM Standard?

answer

C172

question

The maximum size aggregate allowed in this test method is_____.

answer

1 1/2 in. (37.5 mm)

question

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

question

When filling the bowl of the air meter, the concrete must be placed in _____ layers of equal depth.

answer

2

question

What is the specified number of strokes required when rodding each layer of concrete?

answer

25

question

It is necessary to tap the sides of the bowl after each layer has been rodded. True or False?

answer

True

question

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

question

Upon final filling of the air meter with water, what part of the liquid level should be adjusted to teh zero mark on the meter?

answer

Bottom of the meniscus

question

How long should the air meter be inverted and agitated?

answer

No more than five seconds at a time, but must be repeated for a minimum of 45 seconds to free concrete from the base

question

How many times does the rolling operation occur?

answer

A minimum of 2, a minimum of 3

question

Why is the isopropyl alcohol added to the meter?

answer

To dispel any foam that may be on the surface of the water

question

The direct reading of the final liquid level in the neck of the air meter, is estimated to teh nearest _____.

answer

0.25%

question

If the air content is greater than the 9% range of the meter, _____.

answer

Calibrated cups of water are added to ring the liquid level within the graduated range

question

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?

answer

True

question

If less than 2.5 pints of alcohol are used, the air content is always indicated by the inal meter reading. True or False?

answer

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

question

If more than 2.5 pints of alcohol are used, the final meter reading is always adjusted using _____.

answer

A correction factor

question

When large amounts of alcohol are used, the direct reading will tend to indicate a _____ air content.

answer

Higher

question

At the end of the procedure, the air meter is _____.

answer

Disassembled and its contents examined

question

If portions of undisturbed concrete are found in the air meter at the end of the test, _____.

answer

The test is invalid

question

ASTM Method gives standardized requirements for _____, _____, _____, and _____, of test specimens.

answer

Making, curing, protecting, transporting

question

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 _____.

answer

5/8 +- 1/16 in [16 mm +- 2 mm]

question

The minimum frequency of an internal vibrator used in this procedure is _____.

answer

9000 vibrations per minute [150 Hz]

question

The container for obtaining the concrete sample used in this procedure can be a _____, _____, or _____.

answer

Metal pan, wheelbarrow, flat, clean nonabsorbent mixing board

question

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.

answer

2 in. [50 mm]

question

The sample of concrete used in molding test specimens must be obtained in accordance with what ASTM Standard?

answer

C172

question

When strenght specimens are to be made, what three other tests must be made?

answer

Slump, air content, temperature

question

After molding test specimens, you should wait two hours before moving them to the location of initial storage. True or False?

answer

False; the specimens must be moved immediately

question

The supporting surface on which specimens are stored shall be level within _____.

answer

1/4 in. per ft. [20 mm per m]

question

For concrete with a slump of less than 1 in. [25 mm], the test specimens must be consolidated by _____.

answer

Vibration

question

If the concrete is to be consolidated by vibration, a standard 4 by 8 in. [100 mm by 200 mm] cylinder mold must be filled in _____ equal layers.

answer

2

question

When rodding a standard 6 by 12 in [150 mm by 300 mm] cylinder, each layer must be rodded _____ times.

answer

25

question

When rodding each upper layer of concrete in a cylinder, the tamping rod should penetrate into the underlying layer by about _____.

answer

1 in. [25 mm]

question

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.

answer

2

question

When consolidating a flexural strength test specimen by rodding, rod one stroke for each _____ of top surface area.

answer

2 in.^2 [14 cm^2]

question

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.

answer

6 in. [150 mm]

question

Concrete mixtures with specified strengths of 6000 psi [40 MPa] or greater shall have an initial curing temperature between __________.

answer

68 and 78 degrees F [20 and 26 C]

question

Up to 48 hours after molding, test specimens that are to be standard cured shall be stored in a temperature range between _____ to _____.

answer

60 and 70 degrees F [16 and 27 C]

question

Upon completion of initial curing, the test specimens may be left in their molds and sealed in plastic bags. True or False?

answer

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]

question

During transportation, test specimens must be protected from damage due to _____, _____, and _____.

answer

Jarring, freezing temperatures, moisture loss

question

Specimens shall not be transported until _____ after final set.

answer

8h

question

Transportation time shall not exceed _____.

answer

4h

question

Standard Curing is the curing method used when test specimens are to be used for _________.

answer

Acceptance testing for specified strength, checking the adequacy of mixture proportions for strength, quality control

question

Field Curing is the curing method used when test specimens are to be used for __________.

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

question

Cylinders that are to be field cured are stored __________ and protected __________.

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

question

The temperature and moisture environment for field cured cylinders must be __________.

answer

The same as the structural work

question

Cylinders made for the purpose of determining when a structure may be put into service shall be removed from the mold __________.

answer

At the time of the removal of formwork

ACI Concrete Field Testing Technician- Grade I

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