Simplified Design for Footings - Simplified Design of Reinforced Concrete Buildings - page 223

L

3" 3"

c 1

Figure 7-5 Available Development Length for Footing Reinforcement

All of the spacing and cover criteria depicted in Fig. 7-6 are usually satisfied in typical situations; therefore,

d can be computed from the following (ACI 12.2):

For No. 6 and smaller:

f y ψ t ψ e
25

d = d b

λ ʹ f c

For No. 7 and larger:

f y ψ t ψ e
20

d = d b

λ ʹ f c

ψ e and λ are factors depend on the bar location coating and concrete type (lightweight or normal-
weight). For normalweight concrete reinforced with uncoated bars located at the bottom of the footing, the
multiplier

ψ e ,

Where

ψ e ψ e

and the value of λ can be taken as 1.0.

Values of d for › = 3000 psi to 6000 psi are given in Table 7-1. In cases where the spacing and/or cover are

less than those given in Fig. 7-6, a more detailed analysis using the appropriate modification factors in ACI
12.2 must be performed to obtain d .

7.6 FOOTING DOWELS

7.6.1 Vertical Force Transfer at Base of Column

The following discussion addresses footing dowels designed to transfer compression forces only. Tensile
forces created by moments, uplift, or other causes must be transferred to the footings entirely by reinforcement
(ACI 15.8.1.2).