CCIL Hot Mix Asphalt Field Density Testing 3

Question 1

What is the primary laboratory use of a pavement core extracted from a compacted HMA mat?

Accepted Answer

To determine bulk specific gravity for in-place density calculation

Answer

To measure air temperature recorded during paving

Answer

To determine the aggregate gradation of the compacted mat

Answer

To measure the residual binder viscosity after compaction

Question 2

Which ASTM standard is used to determine the bulk specific gravity of non-absorptive compacted HMA specimens (cores)?

Accepted Answer

ASTM D2726

Answer

ASTM D1073

Answer

ASTM D4791

Answer

ASTM D5444

Question 3

In HMA quality acceptance specifications, what is a 'lot'?

Accepted Answer

A defined quantity of pavement production used as the statistical unit for acceptance decisions

Answer

A single nuclear gauge reading location

Answer

The aggregate stockpile at the mixing plant

Answer

One truckload of HMA delivered to the project site

Question 4

What does PWL stand for in statistical HMA density acceptance specifications?

Accepted Answer

Percent Within Limits

Answer

Pavement Weight Limit

Answer

Plant Weight Load

Answer

Pavement Warranty Liability

Question 5

If the bulk specific gravity of a core is 2.350 and the maximum theoretical density is 2.500, what is the percent compaction?

Accepted Answer

94.0%

Answer

88.0%

Answer

106.4%

Answer

93.5%

Question 6

Why is a correction factor (bias correction) applied when comparing nuclear gauge readings to core density values?

Accepted Answer

To account for systematic differences between nuclear gauge readings and laboratory bulk specific gravity results

Answer

To compensate for differences in aggregate mineralogy between lots

Answer

To adjust measurements for changes in ambient air temperature

Answer

To normalize results obtained by different gauge operators

Question 7

What is the appropriate action when a nuclear density gauge fails to produce a standard count within acceptable control limits?

Accepted Answer

Remove the gauge from service until it is inspected, recalibrated, or repaired

Answer

Continue testing and note the anomaly in the field report

Answer

Increase the measurement count time to compensate for the drift

Answer

Use the previous day's standard count as a substitute reference value