Nonlinear Material Behavior of the Bridge Components - Finite Element Analysis and Design of Steel and Steel-Concrete Composite Bridges - page 77

Table 2.14 Properties of reinforcement specified in EC2 [ 2.27 ]

Bars and
Decoiled
Rods

Requirement or
Quantile Value
(%)

Wire
Fabrics

Product Form

Class A B C A B C

-

Fatigue stress range (MPa) (for
N 2 10 6 cycles) with an upper
limit of bf yk

150 100 10.0

Bond Nominal

bar size
(mm)

5.0

Minimum relative rib area, f R,min 5-6 0.035

6.5-12 0.04

> 12 0.056

s s

f t = kf 0.2k

f t = kf yk
f yk

f 0.2k

e uk e 0.2% e uk e

(a)
Figure 2.10 Stress-strain diagrams of typical reinforcing steel specified in EC2 [ 2.27 ] .

(b) Hot rolled steel Cold worked steel

the area of the thicker wire if the two are different. EC2 specifies that
where fatigue strength is required, it shall be verified in accordance with
EN 10080 [ 2.14 ]. The design of concrete cross sections with reinforce-
ment bars should be based on the nominal cross-sectional area of the rein-
forcement and the design values derived from the characteristic values
giveninEC2[ 2.27 , 2.28 ] . For normal design (see Figure 2.11 ) , either
an inclined top branch with a strain limit of e ud and a maximum stress
of kf yk / g S at e uk ,where k¼ ( f t / f y ) k , or a horizontal top branch without
the need to check the strain limit canbeused.Therecommendedvalue
specified in EC2 [ 2.27 , 2.28 ] for e ud is 0.9 e uk . The mean value of density
may be assumed to be 7850 kg/m 3 . The design value of the modulus of
elasticity, E S , may be assumed to be 200 GPa.