Design of a one-way slab - Reinforced Concrete with FRP Bars: Mechanics and Design - page 202

The ACI 440.6.1R-06 minimum manufacturer's guaranteed mechanical
properties of the selected bars are the following:

f fuu = 100 ∙ ksi Ultimate guaranteed tensile strength of the FRP

ε fuu = 0.018 Ultimate guaranteed rupture strain of the FRP

E f = 5700 ∙ ksi Guaranteed tensile modulus of elasticity of the FRP

E
E

f
c

Ratio of modulus of elasticity of bars to modulus of
elasticity of concrete

n = =1.399

f

The geometrical properties of the selected bars are the following:

ϕ f_bar = 0.5 ∙ in. Bar diameter

A f_bar = 0.196 ∙ in. 2 Bar area

FRP reduction factors: Table 7-1 of ACI 440.1R-06 is used to define
the environmental reduction factor, C E . The type of exposure has to be
selected:

Ty pe_of_Exposure :=

Interior
Exterior

C E = 0.8 Environmental reduction factor for GFRP

Table 8-3 of ACI 440.1R-06 is used to define the reduction factor to take
into account the FRP creep rupture stress. Creep stress in the FRP is evalu-
ated considering the total unfactored dead loads and the sustained portion
of the live load (20% of the total live load):

k creep _ R = 0.2 Creep-rupture stress limitation factor

Crack width is checked using Equation (8-9) of ACI 440.1R-06. A crack
width limit, w lim , of 0.028 in. is used for interior exposure, while 0.020 in.
is used for exterior exposure:

w lim = 0.028∙in Crack width limit

FRP ultimate design properties: The ultimate design properties are cal-
culated per Section 7.2 of ACI 440.1R-06:

f fu := C E ∙f fuu = 80∙ksi Design tensile strength
ε fu := C E ∙ε fuu = 0.014 Design rupture strain