Background Knowledge - Strengthening Design of Reinforced Concrete with FRP - page 25

Vd
M

u

V =λ+ 1.9 f 2500 ρ bd

(2.30)

c c w w

m

=− −

4 hd

(2.31)

MMN

m u u

8

N

u

V ≤λ + 3.5 f bd 1

(2.32)

c c w

500 A

g

and in the case of shear, flexure, and axial tension,

N

u

V =+ λ 21 fbd ≥ 0

(2.33)

c cw

500 A

g

where N u is negative, N u / A g is in psi, and f c ≤ 100 psi except as in Section 11.1.2.1

of ACI 318-11.
For shear strength of stirrups perpendicular to the axis of member,

Af d
S

v t

V = (2.34)

s

For shear strength of stirrups inclined with respect to the axis of member,

( )

Af sin os α+ α d

v t

(2.35)

V =

s

S

where S is the stirrup spacing = minimum

(,24")
2

( )

If V > 4 f bd , S = minimum

d

, 12"

s c w

4

V

If V >φ , se A

c

u v ,min

2

with exceptions in Section 11.4.6.1 of ACI 318-11

bS
f

, 50

bS
f

w
yt

w
yt

(2.36)

A = max 0.75 f

v ,min c