CTQP Materials Sampling and Testing 5

Question 1

When computing the average of two companion concrete cylinder breaks, if one result deviates more than what percentage from the average, additional cylinders must be tested?

Accepted Answer

15%

Answer

Per ASTM C39, if individual cylinder strength deviates more than 8% of the average, ASTM C39 recommends investigating; many agency specs use a 10% threshold for triggering additional testing.

Question 2

The Atterberg limits test is used to characterize which property of fine-grained soils?

Accepted Answer

Plasticity and moisture sensitivity

Answer

Atterberg limits (liquid limit, plastic limit, plasticity index) classify fine-grained soil plasticity and its sensitivity to moisture changes.

Question 3

The purpose of the Los Angeles Abrasion test (AASHTO T 96) is to measure:

Accepted Answer

Resistance of aggregate to degradation by impact and abrasion

Answer

The LA Abrasion test measures the percentage of material lost when aggregate is subjected to impact and grinding inside a rotating steel drum with steel balls.

Question 4

A volumetric flask used in specific gravity testing of fine aggregate must be calibrated at what temperature?

Accepted Answer

73.4°F (23°C)

Answer

AASHTO T 84 requires calibration of the pycnometer or volumetric flask at 73.4°F (23°C) to ensure accurate volume measurements.

Question 5

When obtaining a core sample from an asphalt pavement for thickness verification, the minimum core diameter recommended by FDOT specifications is:

Accepted Answer

4 inches

Answer

A minimum 4-inch diameter core is typically required for asphalt thickness and density testing to ensure a representative sample with adequate material for testing.

CTQP - Construction Training & Qualification Program Practice Test

CTQP - Construction Training & Qualification Program Practice Test

CTQP Materials Sampling and Testing 5