Masonry Magazine February 1979 Page. 30
TABLE 4. Maximum Wall Heights for Non-reinforced Hollow Unit Concrete Masonry Walls Subjected to Concentric Loads and Wind (w, psf)*
Maximum wall heights, feet**
| Concentric Load, Ib. | t = 6 in. | t = 8 in. | t = 10 in. | t = 12 in. |
|---|---|---|---|---|
| | w=10 | 20 | 30 | 10 | 20 | 30 | 10 | 20 | 30 | 10 | 20 | 30 |
| 0 | 10.0 | 7.1 | 5.8 | 12.8 | 9.0 | 7.4 | 16.0 | 11.3 | 9.2 | 19.6 | 13.9 | 11.4 |
| 500 | | 8.4 | 6.9 | 13.3 | 10.5 | 8.6 | 16.7 | 12.7 | 10.4 | 20.0 | 15.4 | 12.6 |
| 1000 | | 9.6 | 7.8 | | 11.9 | 9.7 | | 14.0 | 11.4 | | 16.8 | 13.8 |
| 1500 | | 10.0 | 8.7 | | 13.0 | 10.6 | | 15.2 | 12.4 | | 18.2 | 14.8 |
| 2000 | | | 9.4 | | 13.3 | 11.5 | | 16.2 | 13.3 | | 19.3 | 15.8 |
| 2500 | | | 10.0 | | | 12.4 | | 16.7 | 14.1 | | 20.0 | 16.7 |
| 3000 | | | | | | 13.1 | | | 14.9 | | | 17.6 |
| 3500 | | | | | | 13.3 | | | 15.6 | | | 18.4 |
| 4000 | | | | | | | | | 16.3 | | | 19.2 |
| 4500 | | | | | | | | | 16.7 | | | 20.0 |
*Design assumptions: Minimum f'm = 1350 psi; type S mortar, allowable flexural semile stress = 23 x 1.33 = 30.6 psi.
**Maximum wall heights limited to 20 t (see Table 1)
TABLE 5. Allowable Vertical Axial Loads for Reinforced Hollow Unit Concrete Masonry Walls Subject to Wind (w, psf)*
Allowable Vertical Axial Load, Kips per lineal foot
| Wall height, feet | 6-in. wall with No. 4 bars @ 32" o.c. | 8-in. wall with No. 5 bars @ 32" o.c. | 10-in. wall with No. 6 bars @ 32" o.c. | 12-in wall with No. 7 bars @ 32" o.c. |
|---|---|---|---|---|
| | w = 10 | 20 | 30 | 10 | 20 | 30 | 10 | 20 | 30 | 10 | 20 | 30 |
| 8 | 12.6 | 9.9 | 7.3 | 18.0 | 16.3 | 14.5 | 23.1 | 21.8 | 20.5 | 27.8 | 26.8 | 25.8 |
| 10 | 10.4 | 6.5 | 2.6 | 16.6 | 13.9 | 11.1 | 22.1 | 20.0 | 18.0 | 27.1 | 25.5 | 23.9 |
| 12 | 7.8 | 2.7 | | 14.8 | 11.0 | 7.2 | 20.7 | 17.9 | 15.0 | 26.0 | 23.7 | 21.5 |
| 14 | 5.0 | | | 12.6 | 7.8 | 2.9 | 19.1 | 15.3 | 11.5 | 24.8 | 21.8 | 18.8 |
| 15 | 3.6 | | | 11.0 | 5.9 | | 18.0 | 13.8 | 9.5 | 24.0 | 20.5 | 17.1 |
| 16 | | | | 10.2 | 4.4 | | 17.3 | 12.5 | 7.7 | 23.2 | 19.4 | 15.5 |
| 18 | | | | 7.7 | | | 15.2 | 9.4 | 3.7 | 21.7 | 16.9 | 12.2 |
| 20 | | | | 5.1 | | | 12.8 | 6.3 | | 19.5 | 13.9 | 8.3 |
| 22 | | | | | | | 10.4 | 3.2 | | 17.8 | 11.2 | 4.7 |
| 24 | | | | | | | 7.9 | | | 15.1 | 8.0 | |
| 25 | | | | | | | 6.7 | | | 13.9 | 6.5 | |
| 26 | | | | | | | | | | 13.2 | 5.3 | |
| 30 | | | | | | | | | | 8.4 | | |
*Based on Reference 6: f'm = 1500 psi; reinforcing bars are centered on wall.
NATIONAL CONCRETE MASONRY ASSOCIATION
P.O. Box 781, Herndon, Virginia 22070