PSI - Issue 62

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

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Table 5. Average cost of GFRP bars and steel bars observed in the Italian market.

Concrete reinforcement

Description

Steel bars

GFRP bars



Average cost of straight bars Average cost of shaped bars Average cost of  10 straight bars Average cost of  10 shaped bars

1.68 1.68 1.03 1.03

€/kg €/kg €/m €/m

6.50 8.00 1.02 1.26

€/kg €/kg €/m €/m

287 % 376 %

-1

% %

22

In order to compute the global costs for a barrier replacement project, it is necessary to take into account: • reinforcement cost (stirrups and longitudinal bars); • demolition and reconstruction costs of the curb; • barrier cost. Table 6 shows the construction cost per meter of length required for a barrier replacement, the last column contains the percentage difference between GFRP application and steel application.

Table 6. Cost comparison.

Construction Cost

Description

Steel bars

GFRP bars



Rebars

69

€/m €/m €/m €/m

93

€/m €/m €/m €/m

33.5 %

Concrete curb

247 395 711

247 395 734

- -

Barrier

Total

3.3

%

5. Conclusions According to the analytical studies presented in this work, we could point out the following main aspects. • Several international guidelines are currently available supporting design, construction, and control of fiber reinforced polymer composites. GFRP rebars are not mentioned in EN 1992-4, even though GFRP-reinforced curb has been proven to have comparable safety factors to its steel reinforced counterparts (as showed in Table 4). • Bending of fibers in GFRP significantly affects the strength resistance of the bars. This reduction is caused by the misalignment of fibers resulting from the molding process. For this reason, despite higher tensile strength, it is necessary to use greater GFRP stirrups diameter to reach the same performance of steel stirrups. Regarding this aspect, we cannot exclude the point that future improvement of the manufacturing process of Glass Fiber Reinforced Polymer could resolve this problem. • GFRP bars are more expensive than steel bars. The required amount of GFRP could cost over 30% more than steel for a bridge curb. Nevertheless, analyzing the overall costs required for a barrier replacement project the cost difference between these two types of reinforcement is less than 5% (as shown in Table 6). Considering the life cycle cost of a curb the use of GFRP is economically more advantageous than steel preserving durability of the structures and reducing maintenance costs during the service life of the bridge.