ACI Concrete Field Testing Technician

ACI Concrete Field Testing Technician Grade I Certification Exam Practice Questions And Correct Answers (Verified Answers) Plus Rationales 2026 Q&A | Instant Download Pdf

• What is the primary purpose of ASTM standards in concrete testing?
• To reduce construction costs
• To ensure uniform testing procedures
• To provide standardized methods for testing concrete materials
• To replace local building codes

Italicized Rationale: ASTM standards ensure consistency, reliability,

and comparability of concrete test results across projects and laboratories.

• Which ASTM standard covers sampling fresh concrete?

A. ASTM C39

B. ASTM C172 1 / 4

C. ASTM C31

D. ASTM C143

Italicized Rationale: ASTM C172 specifically addresses procedures for

sampling freshly mixed concrete.

• What is the minimum size of a composite sample according to ASTM

C172?

• 0.5 cubic feet
• 1 cubic foot
• 1.5 cubic feet
• 2 cubic feet

Italicized Rationale: ASTM C172 requires a composite sample of at

least 1 cubic foot to ensure representativeness.

• Which test determines the consistency of fresh concrete?
• Air content test
• Unit weight test
• Slump test
• Strength test

Italicized Rationale: The slump test (ASTM C143) measures the

consistency and workability of fresh concrete.

• What is the height of the slump cone?
• 8 inches
• 10 inches
• 12 inches 2 / 4

• 14 inches

Italicized Rationale: The standard slump cone height is 12 inches as

specified in ASTM C143.

• How many layers are used when filling the slump cone?
• Two
• Three
• Four
• Five

Italicized Rationale: The slump cone is filled in three equal layers,

each rodded 25 times.

• What is the diameter of the slump cone base?
• 6 inches
• 7 inches
• 8 inches
• 10 inches

Italicized Rationale: The base diameter of the slump cone is 8 inches

per ASTM requirements.

• How many times is each layer rodded during the slump test?
• 10
• 15
• 25

D. 50 3 / 4

Italicized Rationale: Each layer is rodded 25 times to properly

consolidate the concrete.

• When should the slump test be performed after sampling?
• Within 5 minutes
• Within 15 minutes
• Within 30 minutes
• Within 1 hour

Italicized Rationale: ASTM C143 requires the slump test to begin

within 15 minutes after sampling.

• What does an excessively high slump indicate?
• Low water content
• Too much water in the mix
• Proper workability
• High strength

Italicized Rationale: A very high slump often indicates excess water,

which can reduce strength and durability.

• Which test measures the air content of freshly mixed concrete

by pressure method?

A. ASTM C138

B. ASTM C231

C. ASTM C173

• ASTM C39
• / 4