PSI - Issue 62

Andrea Maffei et al. / Procedia Structural Integrity 62 (2024) 1006–1013 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

1010

5

Table 1. Material.

Concrete reinforcement

Description

Steel bars

GFRP bars

Concrete class

C40/50

Barrier

Steel Grade S235 3xM24 Class 8.8  Rk,ucr = 15 MPa

Fasteners

Characteristic bond resistance (uncracked)

Longitudinal bars

 16 f fk  800 MPa  14/150 f fk  800 MPa

 16 B450C  12/150 B450C

Stirrups

Table 2. Rebar comparison.

Concrete reinforcement

Steel bars

GFRP bars

Modulus of elasticity E

210000 MPa Modulus of elasticity E

40000 MPa 8.0 MPa

Bond strength of supplementary reinforcement f bk Partial factor (accidental design situation)  c Bond strength of supplementary reinforcement f bd

5.53

MPa Bond strength of supplementary reinforcement f bk

1.2

-

1.2

-

Partial factor (accidental design situation)  c

4.61 450

MPa Bond strength of supplementary reinforcement f bd

6.67 MPa 800 MPa

MPa Characteristic tensile strength f fk

Characteristic yielding strength f yk

1.0

- - -

1.0 0.7 2.0

- - -

Partial factor (accidental design situation)  s Conversion factor (environmental + long term) 

Partial factor (accidental design situation)  s Conversion factor (environmental + long term) 

- -

Material partial factor

Bending effect partial factor  f, 

450

MPa Design value f fd

280 MPa

Design value f yd

3.2. Design criteria and verifications outcomes The design of the curb reinforcement is realized by considering the impact load of a vehicle in the event of a collision, according to the Italian construction code (NTC18). The impact load is computed considering the yield of the barrier post as shown in Table 3.

Table 3. Impact load.

Impact load

Characteristic yielding strength of the post

235

MPa

Plastic section modulus Plastic bending moment Amplification factor

144.7

cm 3

34.0

kNm

1.5

-

Design plastic bending moment Height from the road surface

51.0 1.00 66.2 62.9

kNm

m

Force at the base plate Moment at the base plate

kN

kNm

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