A3 = [bt **+ **(n - 1)As]

b = The actual width of the column or pilaster, inches.

t = The least actual thickness of the column or pilaster, inches.

n = Modular ratio.

= Es/Em

Es = 29,000,000 psi.

Em = 1000f'm for CMU.

f'm = The compressive strength of masonry, psi.

As = The cross-sectional area of reinforcing steel, in2.

pilasters, Fa, is as follows:

Fa = [0.l8f'm + 0.65(pg)(Fsc)][R] (psi)

(eq 9-2)

Where:

pg = The ratio of the cross-sectional area of the reinforcement to the gross area of the masonry

section based on actual dimensions.

pg = As/Ag

Ag = The gross area of masonry section based on actual dimensions, in2.

Fsc = Allowable compressive stress in steel, psi.

= 0.4fy

R = The stress reduction factor

tn = Least nominal thickness of column or pilaster, inches.

In equation 9-2, the "0.l8f'm" is the allowable axial compressive stress provided by the masonry and the

"0.65pgFsc" is the allowable compressive stress added to the section by the vertical reinforcement. The third

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