Masonry Magazine June 1976 Page. 17
DESIGN EXAMPLE
Design a 4-in. thick (3%-in. actual) 11-ft high bearing wall panel carrying an axial load of 8.5 kips per ft and a 25-psf wind load. Based on an fm 7800 psi resulting from compressive prism tests, design a 1-ft wide vertical strip.
h/t = 11(12)/3.625 = 36.5
C=0.25 from Fig. 5 (assume both ends pinned)
FC=C f'm = 0.25(0.25) (7800) = 488 psi
F=0.33 f'm= 0.33(7800) = 2580 psi
F₁=112 psi (1.33) = 150 psi (33 percent allowable stress increase due to wind)
fa = 8500 / (12(3.625)) = 195 psi
M = 1/8(25) (11) (12) = 4550
fb = M/S = 4550 / (1/6(12) (3.625)^2) = 173 psi
fa/Fa + fb/F₁ = 195/488 + 173/2580 = 0.40+ 0.07 = 0.47 < 1.0 O.K.
fb = 173 < 150 O.K.
If the above wall were non-loadbearing (no axial load), the wall section would not be adequate since the actual bending stress (173 psi) is greater than the allowable stress (150 psi). However, the option of flexural tests is open to the designer. If, for example, full scale transverse strength tests showed an f', of 480 psi, which is not uncommon with Sarabond mortar, the allowable flexural tension stress with wind would be 0.30 (480) (1.33) = 192 psi, which would again allow the wall section to be used.
CASE STUDIES
To illustrate a few possible uses of brick masonry using high-bond mortar, the following three Case Studies are offered. These Case Studies were selected to illustrate three different uses of high-bond brick masonry, i.e., non-loadbearing exterior walls laid in place, non-loadbearing exterior walls prefabricated and lifted into place, and hand-laid loadbearing thin brick masonry walls.
# Dobie Residence Hall, University of Texas, Austin, Texas
The Dobie Residence Hall is a 29-story reinforced concrete skeleton frame structure. It was designed by Daverman Associates of Grand Rapids, Michigan. The residence hall is clad with 3-in. thick prefabricated brick masonry panels. The panels are of many configurations. They were fabricated on the building site in the first floor area of the structure. Then they were erected with a crane and attached to the structural frame with bolts and steel clip angles. Working in three shifts, the mason contractor produced 25 panels per day without interruption from the weather. A total of 72,700 sq ft of brick panels enclose this structure (see Figs. 1 and 9).
# Franklin Office Building, Denver, Colorado
This 3-story office building consists of 4-in. nominal thickness exterior bearing walls with precast concrete double-tee floor slabs. The stems or web sections of the precast concrete slabs project through the bearing wall and are utilized as a design feature on the building and also provide a full-4-in. bearing on the thin high-bond brick masonry walls (see Figs. 10 and 11).