ACI Grade 1 Field Testing Certification Practice Test - Irving

For concrete with aggregates less than 3 inches, the thermometer must remain in the fresh concrete sample a minimum of 5 minutes or until the temperature reading stabilizes. (T or F)

False (2-5 minutes)

The temperature measuring device must be accurate to within 0.1 degree. (T or F)

The temperature measuring device shall have a capacity of measuring temperature of freshly mixed concrete throughout a range of _____ to _____ degree F ( ______ to ______ degree C)

30 to 120 degree F ( 0 to 50 degree C)

A composite sample is not needed if only the temperature test is being run. (T or F)

True

The temperature of fresh concrete in a placement must be measured by inserting a thermometer into the top six inches of concrete. (T or F)

False (3 in.)

The temperature of the concrete is recorded to the nearest ______ degree F (______ degree C)

1 degree F (0.5 degree C)

ASTM C1064 states the container used to measure temperature of concrete must be large enough to provide at least 5 inches of concrete around the sensor. (T or F)

Calibrate the temperature measuring device at least __________, or whenever there is a question of accuracy.

Annually

After the thermometer is placed in the concrete:

Gently press concrete around the thermometer

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

Verify conformance

It is allowable to remove the temperature measuring devices from the freshly mixed concrete to read the temperature if you cannot see the reading. (T or F)

False

The maximum allowable time between obtaining the first and last portions of the composite sample may not exceed 5 minutes. (T or F)

False

Start molding specimens for strength tests within 30 minutes after fabricating the composite sample. (T or F)

False (15 mins)

The composite concrete sample must be protected from sun, wind, contamination and rapid evaporation. (T or F)

False (Contamination and rapid evaporation)

If the concrete contains aggregates larger than those that are appropriate for a size of mold or equipment used, the sample should be wet-sieved before making the test. (T or F)

False (wet screened)

The composite sample not be remixed before beginning any tests. (T or F)

False

Sampling should normally be performed, as the concrete is discharged from the mixer. (T or F)

True

ASTM Method C172 includes the sampling from stationary mixers, paving mixers, truck mixers, agitators, and non-agitating equipment. (T or F)

True

After sampling is completed, start the tests for slump and air content within:

None of the above (5 mins)

In any case, do not obtain samples until:

All the water and admixtures have been added to the concrete

No samples shall be taken before ______ or after ______ of the batch has been discharged.

When strength tests are to be made, the minimum size of the composite sample shall be:

1 cubic foot

Sample the concrete from the chute of a truck mixer by:

Fresh concrete to be tested at the job site should be sampled from:

Two or more regularly spaced intervals during discharge of the middle portion of the batch

The elapsed time between obtaining the first and final portions of the composite sample, according to ASTM C172, shall not exceed:

None of the above

The sides of the slump cone should be tapped with the mallet to consolidate the concrete in the mold. (T or F)

False

For the slump test, when Rodding the second layer and the top layer, the tamping rod should just penetrate into the underlying layer. (T or F)

True

According to ASTM C143, it is permissible to use a mold, which clamps to a non-absorbent base. (T or F)

True

When filling the final layer of the slump cone, never heap the concrete above the top of the mold. (T or F)

False

The filling of the slump cone should be done in three layers of equal height. (T or F)

False

The slump test may be done on any flat surface. (T or F)

False

When filling the slump cone, each layer should be rodded 25 times. (T or F)

True

The slump cone is filled in three layers of equal volume. (T or F)

True

Concrete should be removed from around the base before the cone is lifted. (T or F)

True

The slump cone should be raised carefully, vertically upward, in a steady motion in ________ Seconds

3 to 7

The elapsed time between the start of filling the slump cone and the removal of the cone must be no more than:

2 1/2 minutes

The slump should be measured to the nearest

Quarter of an inch

In order to determine slump, you should measure the vertical distance from:

Top of the mold to the displaced original center of the top surface

The dimensions of the slump cone are:

Top diameter 4 inches, bottom diameter 8 inches, height 12 inches

In the slump test, if a decided falling away or shearing off the concrete from one side or portion of the mass occurs upon raising the slump cone, one should:

Disregard the test and make a new test on another portion of the sample

The slump cone should be struck-off with:

The tamping rod

The slump cone must be placed:

On a flat moist, non-absorbent, rigid surface

When rodding the second and third layers, the rod should penetrate the preceding layer by about 1 inch. (T or F)

True

The normal ½ cubic foot bucket may not be used to determine Density (unit weight) of lightweight concrete. (T or F)

False (0.2 bucket)

Concrete slump of less than 1 inch should be consolidated using a vibrator. (T or F)

True

ASTM C138 states, "the minimum capacity of the bucket depends on the maximum slump requirement." (T or F)

False

According to ASTM C138, after rodding each layer, tap the sides of the container, with the rod exactly 25 times. (T or F)

False

The outside of the density bucket should be cleaned before weighing. (T or F)

True

Concrete with a slump less than 1 inch should be rodded 25 times per layer. (T or F)

False (Use Vibrator)

According to C138, concretes with slumps of 1-3 inches may be compacted with the vibrator or the rod. (T or F)

True

The unit weight bucket must be calibrated at least once a month. (T or F)

False

According to ASTM C138, when rodding the bottom layer, the rod shall not forcibly strike the bottom of the measure. (T or F)

True

The strike-off plate must be:

At least 1/4 inch thick if metal

At least 1/2 inch thick if glass or acrylic

Flat

(All of the above)

Given the following: wt of bucket 16.2 lbs, volume of bucket =0.498 cf, wt of bucket and concrete 88.5 lbs.

177.2 lb/ft^3

What is the optimum amount of the concrete that should be protruding above the top of the mold after the third layer has been tapped by the mallet?

About a 1/8th inch

After strike-off, the next operation is:

Clean the excess concrete from the exterior of the measure

Strike-off density (unit weight) bucket by:

Using a flat plate in a sawing motion

If the density (unit weight) of concrete is 146 lb/ft³ and the total batch weight is 35,468 lb., what is the yield?

9.0 yd^3

The tamping, rod used for the unit weight test:

A round, straight steel rod

Has a 5/8 diameter with the tamping end rounded

Is approximately 24 inches in length

(All of the above)

For a design batch of 9.0 cubic yards, the total weight of all materials batched was 36,400 lb., and the actual yield was 9.5 cubic yards. What was the relative yield?

1.06

Determine the air content. Total material batched 37,500 lbs...design yield 9.0 yd³...theoretical unit wt. 150.0 lbs/ft³...actual unit wt. 140.0 lbs/ft³ actual yield 9.6 yd³

6.7%

The pressure method should be used for determining the air content of concrete containing lightweight aggregates. (T or F)

False

The aggregate correction factor should only be used when concrete containing lightweight aggregate is being tested. (T or F)

False

After consolidation, if the measure contains a great excess of material, remove a quantity of representative concrete then strike off the surface. (T or F)

True

ASTM C231 covers procedures for both Type A and Type B meters. (T or F)

True

During filling with water, once water emerges through the opposite petcock, the Type B pressure meter should be jarred to expel all air bubbles through the petcock. (T or F)

True

Using the Type B meter, the gauge should read to the nearest 0.1%. (T or F)

True

Wet sieving is needed when the sample of fresh concrete contains aggregates larger than 2 inches. (T or F)

True

After the Type B pressure meter is filled with water and all the air has been expelled through the petcock:

Close the bleeder valve and pump up the pressure chamber and adjust the gauge to the initial pressure line

Given that the reading on the pressure gauge is 5.3 percent, unit weight=143.7 lbs/cf, slump=6.5 inches, and aggregate correction factor is 0.2 percent, what is the air content?

To determine the air content use the Type B meter:

Read the gauge and subtract the aggregate correction factor

After the Type B meter bowl is struck-off, cleaned and the lid is clamped on:

Open the main air and air bleeder valves, open both petcocks and fill with water

Just Prior to adding concrete to the bowl you should:

Dampen the bowl and place it on a flat, level, non-absorbent, and firm surface

Rod each Layer of concrete:

Exactly 25 times

This test method cannot be used to determine the air content of concrete containing lightweight aggregates. (T or F)

False

The rollameter base should be filled in three equal layers by volume. (T or F)

False (2 layers)

Isopropyl alcohol is used only at the end of the test procedures to dispel foam. (T or F)

False

The rollameter should never be used when ambient temperatures are below 60°F. (T or F)

False

If the concrete contains coarse aggregate particles that would be retained on a 1-1/2 in sieve, the concrete must be wet sieved to remove large sizes before testing in the rollameter. (T or F)

True

The rollameter may be used for concretes containing lightweight or normal weight aggregates. (T or F)

True

The calibrated measuring cup is equivalent to approximately 1% of the volume of the bowl of the air meter. (T or F)

True

Always add isopropyl alcohol prior to the initial filling of the meter with liquid. (T or F)

False (Pint of water first)

Immediately after water is added and the cap is tightened, the next step is:

Invert and agitate the unit for at least 45 seconds

Which of the following equipment is not used in the ASTM C173 tests?

Strike off plate

After the meter had been rolled twice with no change in the liquid level and no foam on the surface of the liquid, the direct reading of the liquid in the neck was 3.25%. What was the air content of the concrete? The aggregate correction factor is 0.3% & 2 pints of alcohol were added initially.

Read the liquid level in the neck, estimating to the nearest:

0.25%

After the top is clamped on, fill the rollameter with liquid by:

Using the funnel until the liquid appears in the neck

The rolling procedure must be performed:

With the neck of of the rollameter elevated

Standard concrete specimens for comprehensive strength tests should be "initially" cured at 50 to 90° F. (T or F)

False

Standard compressive strength specimens for acceptance may be 6 X 12 or 4 X 8 inch cylinders. (T or F)

True

While rodding the top two layers, ASTM C31 requires the rod to penetrate the preceding Layer by 4 inches. (T or F)

False

Standard concrete test cylinders shall be molded on a level surface as near as practicable to its initial curing location. (T or F)

True

Never tap the sides of a compression test specimen with the mallet. (T or F)

False

4 X 8 inch cylinders that are rodded should be filled in 3 layers of equal volume. (T or F)

The top of the cylinders should be covered after molding with:

25 times

When rodding ASTM C31 specimens, each layer should be rodded how many times?

A plastic sheet or bag

A plastic cap or lid

A non-absorptive, non reactive plate

(Any of the above)

Standard cured compressive test specimens cannot be transported from the field to the laboratory until:

8 hours after final set

Light-gauge single use molds, susceptible to damage if tapped with the mallet should Be tapped with:

An open hand

Cylinders shipped from the field to the laboratory for testing must be:

Protected from physical damage

Protected from moisture loss

Protected from freezing

(All of of the above)

Final curing for concrete test cylinders for the basis of acceptance that are standard cured:

Shall be with moisture maintained on all surfaces at 73.5 +/-3.5 degree F