ACI 318, Chapter 10 Modifications

Two sections relevant to RAM Concrete Beam within Chapter 10 of ACI 318 were modified from the '02 to the '05 edition. They are documented below.

Section 10.6.4

The equation for the maximum spacing limit for reinforcement closest to the face in tension is:

s = 15 (\frac{40, 000}{f_{s}}) - 2.5 c_{c}

(ACI 318, Eq. 10-4)

but not greater than $12 (\frac{40, 000}{f_{s}})$

where

f_s

the stress in the reinforcement closest to the tension face at service load, computed using unfactored moment.

The code section permits $f_{s} = \frac{2}{3} f_{y}$ , and RAM Concrete Beam uses this assumption in all cases.

The equation for the minimum volumetric spiral reinforcement ratio is:

ρ_{s} = 0.45 (\frac{A_{g}}{A_{c h}} - 1) \frac{{f^{'}}_{c}}{f_{y t}}

(ACI 318, Eq. 10-5)

The value of f_yt shall not exceed 100,000 psi.