Design of a one-way slab - Reinforced Concrete with FRP Bars: Mechanics and Design - page 209

The design flexural strength equation is computed per Equation (8-1) of
ACI 440.1R-06:

ϕ bACI _ 1 M nACI _ 1 = 9∙kip∙ft

“OK” if φ ⋅ MM(M ≥ =2.9 kip ft) ⋅ ⋅

bACI_1 nACI_1 u1 u1

Check_FlexureACI_1 :=

“Not good”otherwise

Check_FlexureACI_1 = “OK”

Embedment length: Because this is a case of negative reinforcement, it
has to be checked if adequate moment capacity can be achieved at the end
of the embedment length. The available length for embedment is

l emb1 := 12 in.

The developable tensile stress is calculated per Equation (11-3) of ACI
440.1R-06. Minimum between cover to bar center and half of the center-
to-center bar spacing is

=⋅

=+ φ , s

f_bar f _bar1

C: c 1in .

b1 c

2 2

Bar location modification factor for top reinforcement but less than 12 in.
of concrete below it is

α Neg1 := 1.0

Required stress in the FRP is

f f1 :=E f ∙ ε f1 (c u1 ) = 80 ∙ ksi

The developable tensile stress (ACI 440.1R-06 Equation 11-3) is

′ ⋅
α

fpsi

l C l

c

emb1 b1 emb1

f f ⋅ 13.6 ⋅ φ + φ ⋅ φ + 340 ≥ f

fu fu

Neg1 f_bar f_bar f_bar

f : =

fd11

fpsi ′ ⋅

l C l

c

emb1 b1 emb1

⋅ 13.6 ⋅ φ + φ ⋅ φ + 340 otherwise

α

Neg1

f_bar f_bar f_bar

= 33.7ksi ⋅