Commercial Building Inspector B2Structural SystemsMedium
A building inspector is reviewing the structural plans for a new single-story commercial building with masonry bearing walls. The plans indicate that the walls are constructed using 8-inch nominal concrete masonry units (CMU) and are fully grouted. What is the minimum specified compressive strength (f'm) required for the masonry based on IBC 2021, assuming special inspection for masonry is provided?
- A2,000 psi
- B1,900 psi
- C1,500 psi
- D2,500 psi
Show answer & explanationAnswer & explanation
Correct answer: C. 1,500 psi
According to IBC 2021 Section 2109.2.1 (based on TMS 402/ACI 530/ASCE 5 Section 1.13.2.1), the minimum specified compressive strength of masonry (f'm) for structures where special inspection for masonry is provided is 1,500 psi (10.3 MPa).
Why the other options are wrong
- A. This is the minimum f'm required when special inspection for masonry is NOT provided, as per IBC 2021.
- B. This value is not a standard minimum for f'm in the IBC.
- D. This value is higher than the minimum required and typically used for more heavily loaded or engineered masonry.
Minimum Masonry f'm (Special Inspection)
The minimum specified compressive strength of masonry (f'm) required by IBC 2021 when special inspection is performed during masonry construction.
- IBC 2021 Section 2109.2.1
- Applies to TMS 402/ACI 530/ASCE 5 Section 1.13.2.1
- Ensures quality control for masonry strength requirements.
Memory trick: Masonry strength minimums depend on inspection rigor.