1|Page
ACI CONCRETE FIELD TESTING TECHNICIAN—GRADE I
CERTIFICATION ACTUAL EXAM PREP 2026 ALL
QUESTIONS AND CORRECT DETAILED ANSWERS WITH
RATIONALES ALREADY A GRADED WITH EXPERT
FEEDBACK |NEW AND REVISED
1. What is the primary purpose of field testing concrete?
A. To assess the concrete's color
B. To verify compliance with specifications and ensure proper
quality
C. To reduce the water content
D. To determine the curing time
Rationale: Field testing ensures that concrete meets project
specifications for strength, consistency, and durability. The tests verify
that the concrete delivered matches the mix design and meets quality
requirements for the intended application.
2. Which ASTM standard covers the practice for making and curing
concrete test specimens in the field?
A. ASTM C172
B. ASTM C31
C. ASTM C143
D. ASTM C138
Rationale: ASTM C31 (Standard Practice for Making and Curing
Concrete Test Specimens in the Field) governs the proper procedures
for molding cylinders and beams for strength testing. C172 covers
sampling, C143 covers slump, and C138 covers unit weight.
,2|Page
3. Which test is used to measure the consistency or workability of
freshly mixed concrete?
A. Slump Test
B. Air Content Test
C. Compressive Strength Test
D. Unit Weight Test
Rationale: The slump test assesses the workability of concrete and
helps identify excessive water or improper mix. It is the standard field
test for evaluating the consistency of freshly mixed concrete.
4. What is the standard size of the slump cone used in testing?
A. 6 in. top × 12 in. bottom × 12 in. height
B. 8 in. top × 12 in. bottom × 12 in. height
C. 4 in. top × 8 in. bottom × 12 in. height
D. 6 in. top × 8 in. bottom × 12 in. height
Rationale: The standard slump cone (ASTM C143) has an 8-inch
diameter top opening, 12-inch diameter bottom opening, and 12-inch
height. This standardized conical mold is essential for consistent
slump measurements.
5. According to ASTM C172, tests for slump, temperature, and air
content must be started within how many minutes after obtaining the
final portion of the composite sample?
A. 2½ minutes
B. 5 minutes
C. 10 minutes
D. 15 minutes
,3|Page
Rationale: The five-minute limit prevents moisture loss or setting
before testing, preserving the concrete's fresh-property
representativeness. These tests must be initiated promptly to ensure
accurate results.
6. The elapsed time between obtaining the first and final portions of a
composite sample shall not exceed:
A. 5 minutes
B. 10 minutes
C. 15 minutes
D. 20 minutes
Rationale: ASTM C172 requires that the elapsed time between
obtaining the first and final portions of a composite sample shall not
exceed 15 minutes to ensure the sample remains representative of the
concrete as delivered.
7. Start molding specimens for strength tests within how many minutes
after fabricating the composite sample?
A. 5 minutes
B. 10 minutes
C. 15 minutes
D. 20 minutes
Rationale: ASTM C31 requires that strength test specimens (cylinders
and beams) be molded within 15 minutes after fabricating the
composite sample to ensure the concrete is still workable and
representative.
, 4|Page
8. What is the minimum immersion depth for the sensor of a temperature
measuring device when testing fresh concrete?
A. 1 inch (25 mm)
B. 2 inches (50 mm)
C. 3 inches (75 mm)
D. 4 inches (100 mm)
Rationale: The sensor of the temperature measuring device shall be
submerged a minimum of 3 inches (75 mm) into the freshly mixed
concrete to ensure the sensor is fully surrounded by concrete,
preventing ambient air from influencing the reading.
9. A thermometer used for concrete temperature measurement must be
accurate to what tolerance?
A. ± 0.5°F (± 0.3°C)
B. ± 1.0°F (± 0.5°C)
C. ± 2.0°F (± 1.1°C)
D. ± 5.0°F (± 2.8°C)
Rationale: The ± 1°F (± 0.5°C) tolerance is required to detect
meaningful temperature variations that can affect concrete properties.
Temperature accuracy is critical for evaluating concrete performance
and compliance.
10. Which ASTM standard covers the procedure for determining the
density (unit weight), yield, and air content (gravimetric) of concrete?
A. ASTM C172
B. ASTM C31
C. ASTM C143
D. ASTM C138
ACI CONCRETE FIELD TESTING TECHNICIAN—GRADE I
CERTIFICATION ACTUAL EXAM PREP 2026 ALL
QUESTIONS AND CORRECT DETAILED ANSWERS WITH
RATIONALES ALREADY A GRADED WITH EXPERT
FEEDBACK |NEW AND REVISED
1. What is the primary purpose of field testing concrete?
A. To assess the concrete's color
B. To verify compliance with specifications and ensure proper
quality
C. To reduce the water content
D. To determine the curing time
Rationale: Field testing ensures that concrete meets project
specifications for strength, consistency, and durability. The tests verify
that the concrete delivered matches the mix design and meets quality
requirements for the intended application.
2. Which ASTM standard covers the practice for making and curing
concrete test specimens in the field?
A. ASTM C172
B. ASTM C31
C. ASTM C143
D. ASTM C138
Rationale: ASTM C31 (Standard Practice for Making and Curing
Concrete Test Specimens in the Field) governs the proper procedures
for molding cylinders and beams for strength testing. C172 covers
sampling, C143 covers slump, and C138 covers unit weight.
,2|Page
3. Which test is used to measure the consistency or workability of
freshly mixed concrete?
A. Slump Test
B. Air Content Test
C. Compressive Strength Test
D. Unit Weight Test
Rationale: The slump test assesses the workability of concrete and
helps identify excessive water or improper mix. It is the standard field
test for evaluating the consistency of freshly mixed concrete.
4. What is the standard size of the slump cone used in testing?
A. 6 in. top × 12 in. bottom × 12 in. height
B. 8 in. top × 12 in. bottom × 12 in. height
C. 4 in. top × 8 in. bottom × 12 in. height
D. 6 in. top × 8 in. bottom × 12 in. height
Rationale: The standard slump cone (ASTM C143) has an 8-inch
diameter top opening, 12-inch diameter bottom opening, and 12-inch
height. This standardized conical mold is essential for consistent
slump measurements.
5. According to ASTM C172, tests for slump, temperature, and air
content must be started within how many minutes after obtaining the
final portion of the composite sample?
A. 2½ minutes
B. 5 minutes
C. 10 minutes
D. 15 minutes
,3|Page
Rationale: The five-minute limit prevents moisture loss or setting
before testing, preserving the concrete's fresh-property
representativeness. These tests must be initiated promptly to ensure
accurate results.
6. The elapsed time between obtaining the first and final portions of a
composite sample shall not exceed:
A. 5 minutes
B. 10 minutes
C. 15 minutes
D. 20 minutes
Rationale: ASTM C172 requires that the elapsed time between
obtaining the first and final portions of a composite sample shall not
exceed 15 minutes to ensure the sample remains representative of the
concrete as delivered.
7. Start molding specimens for strength tests within how many minutes
after fabricating the composite sample?
A. 5 minutes
B. 10 minutes
C. 15 minutes
D. 20 minutes
Rationale: ASTM C31 requires that strength test specimens (cylinders
and beams) be molded within 15 minutes after fabricating the
composite sample to ensure the concrete is still workable and
representative.
, 4|Page
8. What is the minimum immersion depth for the sensor of a temperature
measuring device when testing fresh concrete?
A. 1 inch (25 mm)
B. 2 inches (50 mm)
C. 3 inches (75 mm)
D. 4 inches (100 mm)
Rationale: The sensor of the temperature measuring device shall be
submerged a minimum of 3 inches (75 mm) into the freshly mixed
concrete to ensure the sensor is fully surrounded by concrete,
preventing ambient air from influencing the reading.
9. A thermometer used for concrete temperature measurement must be
accurate to what tolerance?
A. ± 0.5°F (± 0.3°C)
B. ± 1.0°F (± 0.5°C)
C. ± 2.0°F (± 1.1°C)
D. ± 5.0°F (± 2.8°C)
Rationale: The ± 1°F (± 0.5°C) tolerance is required to detect
meaningful temperature variations that can affect concrete properties.
Temperature accuracy is critical for evaluating concrete performance
and compliance.
10. Which ASTM standard covers the procedure for determining the
density (unit weight), yield, and air content (gravimetric) of concrete?
A. ASTM C172
B. ASTM C31
C. ASTM C143
D. ASTM C138
