Commercial Building Inspector B2Structural SystemsEasy
A technician is performing special inspections for a new reinforced concrete high-rise building. The plans specify the use of Grade 60 (fy = 60,000 psi) reinforcing bars. During a site visit, the technician observes that the contractor is using reinforcing bars marked with a different grade stamp. What is the minimum yield strength required for Grade 60 reinforcing bars?
- A75,000 psi
- B60,000 psi
- C40,000 psi
- D50,000 psi
Show answer & explanationAnswer & explanation
Correct answer: B. 60,000 psi
Reinforcing bar grades are directly related to their minimum guaranteed yield strength. Grade 60 indicates a minimum yield strength of 60,000 psi (or 60 ksi). This is a fundamental property for concrete design.
Why the other options are wrong
- A. This is the minimum yield strength for Grade 75 bars.
- C. This is the minimum yield strength for Grade 40 bars.
- D. This is the minimum yield strength for Grade 50 bars.
Reinforcing Bar Grade (Yield Strength)
The numerical designation of a reinforcing steel bar, typically corresponding to its minimum specified yield strength in thousands of pounds per square inch (ksi).
- Common grades: 40, 60, 75, 80, 100, 120.
- Grade number = yield strength in ksi.
- Critical for structural design calculations.
Memory trick: Rebar's grade is its strength.