Technician Practice Exam Level III

Illinois Portland Cement Concrete Technician Practice Exam (Level I/II) Questions And Correct Answers (Verified Answers) Plus Rationales 2026 Q&A | Instant Download Pdf

• What is the minimum cement content typically required for IDOT Class B

concrete?

• 470 lbs/yd³
• 517 lbs/yd³
• 564 lbs/yd³
• 610 lbs/yd³

Rationale: IDOT Class B concrete commonly specifies about 517 lbs/yd³ to

ensure adequate strength and durability.

• What is the standard slump range for IDOT Class A pavement concrete? 1 / 4

• 0–2 inches
• 1–3 inches
• 1–4 inches
• 3–5 inches

Rationale: Class A pavement mix typically targets 1–4 inches for

workability without segregation.

• What is the purpose of an air-entraining admixture in PCC?
• Increase set time
• Reduce cement demand
• Increase slump
• Improve freeze–thaw durability

Rationale: Air entrainment improves durability by creating microscopic air

voids for freeze–thaw pressure relief.

• What is the minimum curing period for IDOT concrete under normal

conditions?

• 24 hours
• 72 hours
• 5 days
• 7 days 2 / 4

Rationale: IDOT requires a minimum of 72 hours of curing unless

accelerated curing allows earlier opening.

• According to ASTM C143, what is the maximum allowed time between

sampling and starting a slump test?

• 1 minute
• 2 minutes
• 5 minutes
• 10 minutes

Rationale: ASTM C143 states slump testing must begin within 5 minutes of

obtaining the final portion of the sample.

• Which ASTM standard covers air content by pressure method?

A. C31

B. C39

C. C231

D. C138

Rationale: ASTM C231 governs the pressure method for determining air

content in fresh concrete.

• What is the typical target air content for concrete exposed to freeze–

thaw cycles in Illinois? 3 / 4

A. 2–4%

B. 4–7%

C. 6–9%

D. 8–10%

Rationale: Air content of 4–7% ensures frost resistance for exterior

structural concrete.

• What is the standard unit weight test method for fresh concrete?

A. ASTM C173

B. ASTM C138

C. ASTM C143

D. ASTM C231

Rationale: ASTM C138 is the test method for density (unit weight) and yield

of concrete.

• A concrete cylinder for compressive strength testing must be cured

initially at what temperature range?

A. 50–60°F

B. 120–140°F

C. 60–80°F

• 80–100°F
• / 4