Design of a T-beam - Reinforced Concrete with FRP Bars: Mechanics and Design - page 254

Ty pe_of_Fiber := Bar_Size :=

#2
#3
#4
#5
#6
#7
#8
#9
#10

Glass
Carbon

ACI 440.6-08 minimum guaranteed mechanical properties of the
selected bars are

f fuu = 80∙ksi Ultimate guaranteed tensile strength of the FRP

ε fuu = 0.014 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: = =1.277

f

The geometrical properties of the selected bars are

ϕ f _ bar = 1∙in. Bar diameter
A f _ bar = 0.785∙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 has to
be evaluated 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