CTQP Materials Sampling and Testing 2

Question 1

What are the two key values determined by the Standard Proctor compaction test (AASHTO T 99)?

Accepted Answer

Maximum dry density and optimum moisture content of a soil

Answer

Bearing capacity and shear strength of the compacted soil

Answer

Permeability and consolidation rate of the soil

Answer

Liquid limit and plastic limit of fine-grained soil

Question 2

What property does the Limerock Bearing Ratio (LBR) test measure for base course materials in Florida?

Accepted Answer

The bearing strength or load-bearing capacity of limerock and similar base course materials

Answer

The weight of limerock material per cubic yard at standard moisture

Answer

The moisture absorption capacity of limerock under saturation conditions

Answer

The unconfined compressive strength of limerock core samples

Question 3

What does the Los Angeles Abrasion test (AASHTO T 96) measure for coarse aggregates?

Accepted Answer

The resistance of coarse aggregate to degradation by abrasion and impact

Answer

The specific gravity and absorption of coarse aggregate particles

Answer

The moisture content of aggregate at the time of sampling

Answer

The gradation and particle size distribution of coarse aggregate

Question 4

What information does a sieve analysis (gradation test) provide about an aggregate sample?

Accepted Answer

The particle size distribution (gradation) of the aggregate

Answer

The moisture content retained by the aggregate particles

Answer

The hardness and abrasion resistance of aggregate particles

Answer

The bulk specific gravity and absorption capacity of the aggregate

Question 5

When performing a concrete slump test per AASHTO T 119, what does a higher slump value indicate about the fresh concrete?

Accepted Answer

Greater workability and more fluid consistency of the fresh concrete

Answer

Higher compressive strength at 28 days

Answer

A lower water-to-cement ratio and stiffer mix

Answer

Better freeze-thaw durability and air entrainment

Question 6

The Atterberg Limits test is used to determine which characteristics of fine-grained soils?

Accepted Answer

The Liquid Limit and Plastic Limit, which define the plasticity of fine-grained soils

Answer

Compressive strength and bearing capacity of cohesive soils

Answer

The permeability and consolidation properties of clay soils

Answer

The unit weight and void ratio of silty and clayey soils

Question 7

Why is it important to measure the air content of fresh concrete on Florida highway projects?

Accepted Answer

To verify that adequate air entrainment is present to ensure durability and resistance to distress

Answer

To determine the water-to-cement ratio before placing concrete

Answer

To measure the compressive strength early before cylinder breaks

Answer

To check that concrete temperature is within specification limits