FDOT Concrete Inspection 2 — Questions and Answers
Question 1: What is the minimum number of cylinders that must be cast per concrete test per FDOT requirements for acceptance testing?
- 1
- 2 (Correct answer)
- 3
- 4
Correct answer: 2
FDOT requires a minimum of 2 cylinders per test set for acceptance, with one tested at 28 days and one held as a check cylinder.
Question 2: According to FDOT, what is the maximum allowable slump for vibrated concrete in bridge deck construction?
- 2 inches
- 3 inches
- 4 inches (Correct answer)
- 5 inches
Correct answer: 4 inches
FDOT specifications limit slump to a maximum of 4 inches for vibrated concrete used in bridge deck construction.
Question 3: What does FDOT Class V concrete designation indicate?
- Low-strength fill concrete
- High-strength structural concrete above 6,000 psi (Correct answer)
- Precast prestressed concrete
- Drilled shaft concrete
Correct answer: High-strength structural concrete above 6,000 psi
FDOT Class V concrete is high-strength concrete with specified compressive strengths exceeding 6,000 psi, used for high-performance applications.
Question 4: When should a concrete inspector reject a load of ready-mix concrete arriving on an FDOT project?
- If drum has rotated more than 100 revolutions
- If more than 90 minutes have elapsed since water was added
- If temperature exceeds 85°F
- All of the above (Correct answer)
Correct answer: All of the above
FDOT specifications require rejection if any of these conditions are met: excessive drum revolutions, time limit exceeded, or concrete temperature too high.
Question 5: What FDOT specification requires contractors to submit a concrete mix design for approval before use?
- Section 105
- Section 346 (Correct answer)
- Section 400
- Section 450
Correct answer: Section 346
FDOT Section 346 requires contractors to submit mix designs for engineer approval prior to beginning concrete placement operations.
Question 6: According to FDOT guidelines, what is the maximum concrete free-fall height permitted during placement to prevent segregation?
- 2 feet
- 3 feet
- 5 feet
- 6 feet (Correct answer)
Correct answer: 6 feet
FDOT limits free-fall height to 6 feet maximum during concrete placement to prevent segregation of aggregates from the paste.
FDOT Concrete Inspection 2
What is the minimum number of cylinders that must be cast per concrete test per FDOT requirements for acceptance testing?