NETTCP Quality Control 4

Question 1

Which AASHTO test method is used to determine the bulk specific gravity of compacted HMA specimens?

Accepted Answer

AASHTO T 166

Answer

AASHTO T 166 determines the bulk specific gravity (Gmb) of compacted bituminous mixtures using the saturated surface-dry (SSD) method.

Question 2

What is the acceptable range for the temperature of fresh Portland cement concrete at the point of delivery, per most state DOT specifications?

Accepted Answer

Between 50°F and 90°F (10°C and 32°C)

Answer

Most transportation agency specifications require fresh concrete temperature at delivery to be between 50°F and 90°F to ensure proper hydration and workability.

Question 3

What is the significance of the 'percent within limits' (PWL) statistic in highway construction QA/QC?

Accepted Answer

It estimates the percentage of a lot that meets specification requirements

Answer

PWL estimates the proportion of the production lot that falls within specification limits, and is used to determine pay factors in many state DOT contracts.

Question 4

During compaction of an embankment, field density tests show 91% relative compaction when 95% is required. Which action is most appropriate?

Accepted Answer

Apply additional roller passes and retest

Answer

When compaction is below the specified minimum, additional roller passes are made to increase density before the next lift is placed, then the area is retested.

Question 5

What information must be recorded on the concrete field test report at the point of sampling?

Accepted Answer

Time of sampling, truck number, load number, air temperature, and test results

Answer

A complete concrete field report requires sampling time, truck and load identification, ambient conditions, and all field test results to ensure traceability.

(NETTCP) New England Transportation Technician Certification Program Practice Test

(NETTCP) New England Transportation Technician Certification Program Practice Test

NETTCP Quality Control 4