CT 216 - Relative Compaction

Question 1

This test method defines relative compaction as the ratio of______to _________, expressed as a percentage.

Answer 1

In-place wet desnity to test maximum wet density.

Question 2

This test does not allow calculating relative compaction on a dry density basis.

Answer 2

False

Question 3

This test method may be used to measure the test maximum density of class A cement treated base.

Answer 3

False

Question 4

It is not important to preserve the moisture content of the sample retreived from the field.

Answer 4

False

Question 5

The minimum weight of a field sample is ________.

Answer 5

35 lbs.

Question 6

If _______ percent or more of the field sample is retained on the 3/4” sieve, the density must be corrected to account for oversized material.

Answer 6

10%

Question 7

The intial wet weight of the test specimen should always be 2500g.

Answer 7

False

Question 8

What is the preferred number of specimens to be prepared?

Answer 8

5

Question 9

How many subspecimens should be created from each specimen?

Answer 9

5

Question 10

Each subspecimen should be compacted with _______ blows from the tamper?

Answer 10

20

Question 11

The piston should be tamped with _________ blows from the tamper to level the surface of the compacted core.

Answer 11

5

Question 12

Always record the tamper reading to the next greatest reading if the top of the mold is between tamper readings.

Answer 12

True

Question 13

Vary the moisture content of each specimen by _________ percent for most materials.

Answer 13

2%

Question 14

The first specimen is typically compacted at the field moisture content.

Answer 14

True

Question 15

Free water on the base plate indicates an excessive moisture content.

Answer 15

True

Question 16

After removing a compacted specimen and reassembly the mold, tighten the wing nuts ________.

Answer 16

With hand pressure.

Question 17

Specimens with moisture content below, at, and above the optimum moisture content are always required to calculate the relative compaction for a test area.

Answer 17

False

Question 18

What is the correct reported relative compcation given the following test results: in-place wet desnity equals 2.01 g/cc, adjusted wet density from 3 tested specimens are 2.07, 2.18, 2.09 g/cc.

Answer 18

92%

Question 19

If less than 10% is retained on the 3/4” sieve, how is the sample then processed?

Answer 19

Discard the material retained on the 3/4” sieve and divide the passing 3/4” fraction into representative 5 test specimens of equal weight.

Question 20

If 10% or more is retained on the 3/4” sieve, how is the sample then processed?

Answer 20

A “Correction for Oversize Material” or “rock correction” must be performed.

Question 21

What is the usual range of specimen weights per Table 1?

Answer 21

2200-2700 grams

Question 22

What should you do if you have a sample that does not have at least one test specimen compacted at a moisture content less than and one greater than the moisture content of the specimen having the highest adjusted wet density within the minimum 3 test specimens (curve not broken)?

Answer 22

Fabricate additional specimens with increased or decreased moisture increments until this condition is satisfied.