The compressive strength of masonry shall be determined based on the strength of the unit and type of mortar specified using Table 2105.2.2.1.2, provided:
1. Units are sampled and tested to verify compliance with ASTM C 55 or ASTM C 90.
2. Thickness of bed joints does not exceed 5/8 inch (15.9 mm).
3. For grouted masonry, the grout meets one of the following requirements:
3.1. Grout conforms to Article 2.2 of TMS 602/ACI 530.1/ASCE 6.
3.2. Minimum grout compressive strength equals or exceeds f'm but not less than 2,000 psi (13.79 MPa). The compressive strength of grout shall be determined in accordance with ASTM C 1019.
TABLE 2105.2.2.1.2
COMPRESSIVE STRENGTH OF CONCRETE MASONRY
| NET AREA COMPRESSIVE STRENGTH OF CONCRETE MASONRY UNITS (psi) | NET AREA COMPRESSIVE STRENGTH OF MASONRY (psi)a | |
| Type M or S mortar | Type N mortar | |
| 1,250 | 1,300 | 1,000 |
| 1,900 | 2,150 | 1,500 |
| 2,800 | 3,050 | 2,000 |
| 3,750 | 4,050 | 2,500 |
| 4,800 | 5,250 | 3,000 |
For SI: 1 inch = 25.4 mm, 1 pound per square inch = 0.00689 MPa.
a. For units less than 4 inches in height, 85 percent of the values listed.