Certification Examination Practice

Illinois Quality Control Inspector Certification Examination Practice Questions And Correct Answers (Verified Answers) Plus Rationales 2026 Q&A | Instant Download Pdf

• Which of the following is the primary purpose of quality control in

construction?

• To reduce labor costs
• To ensure materials and workmanship meet specifications
• To increase project speed
• To satisfy customer preferences

Rationale: Quality control ensures that construction materials,

processes, and final workmanship conform to project specifications.

• What is the minimum compaction required for a typical asphalt base

course? 1 / 4

• 80%
• 85%
• 95%
• 100%

Rationale: Most asphalt base courses require a minimum compaction

of 95% of the maximum dry density to ensure stability.

• When inspecting concrete for air content, which test is commonly

used?

• Slump test
• Air meter test
• Compressive strength test
• Water absorption test

Rationale: The air meter test measures the air content in fresh

concrete, which affects durability and freeze-thaw resistance.

4. A density test of soil is conducted to:

• Measure moisture content
• Ensure proper compaction
• Determine particle size
• Evaluate color uniformity

Rationale: Soil density tests confirm that compaction meets project

specifications, which is critical for structural stability.

• Which ASTM standard covers sampling of aggregates?
• ASTM C31 2 / 4

• ASTM D1557
• ASTM C702
• ASTM D698

Rationale: ASTM C702 specifies procedures for obtaining

representative samples of aggregates for testing.

6. The purpose of a slump test is to measure:

• Air content
• Strength
• Workability of concrete
• Moisture content

Rationale: Slump tests indicate the consistency and workability of

fresh concrete, which affects placement and finishing.

• Which type of inspection is performed continuously during

production?

• Sampling inspection
• Continuous inspection
• Acceptance inspection
• Final inspection

Rationale: Continuous inspection involves ongoing monitoring to

ensure that all work meets quality standards throughout the process.

• A QC inspector observes segregation in freshly mixed concrete. The

proper action is to:

• Place concrete immediately 3 / 4

• Reject the batch
• Add more water
• Compact more thoroughly

Rationale: Segregation indicates inconsistent mix, which can

compromise strength and durability, requiring rejection.

9. The compaction of soil affects:

• Only surface appearance
• Only drainage
• Load-bearing capacity and settlement
• Color uniformity

Rationale: Proper soil compaction improves load-bearing capacity

and minimizes post-construction settlement.

10. Moisture content of soil can be determined using:

• Slump test
• Oven-dry method
• Compression test
• Core sampling

Rationale: The oven-dry method is a standard procedure for

accurately determining soil moisture content.

• Which is the most common method to test asphalt density in the

field?

• Core extraction and laboratory testing
• Nuclear gauge test
• / 4