# FRP Bridges in the Flanders Region: Experiences from the C-Bridge Project
## 3 Selection Criteria for Composite Bridges
### Low Self-Weight  
A first important advantage of FRPs compared to traditional building materials is the low self-weight in relation to the strength and stiffness of the material. This makes it possible to place this type of bridge on a poor load-bearing and swampy underground. Additionally, the dimensions of the foundations can be drastically reduced, and/or existing abutments, piles, or foundations can be reused. An example is the bridge crossing the A27 Highway (bridge No. 1) [29], where it was not possible to use a standard pile foundation since the A27 Highway was constructed below the groundwater level and a foil barrier was installed to retain the groundwater. Drilling through this foil barrier would lead to major groundwater problems, and therefore, the bridge had to be founded on short jet grout columns. For this reason, the bridge had to be designed as light as possible, resulting in the choice of steel truss and an FRP deck with a weight reduction of 800 tons (compared to a full concrete bridge) or 72 tons (compared to a steel deck). Similarly, bridges No. 2 and No. 3 were installed on a swampy underground [30] which in the first case used to be part of a riverbed and in the second case is characterized by a high water table. In both cases, the substructure could be significantly reduced due to the low self-weight of the FRP superstructure. In the case of the Canada Bridge (bridge No. 4) [31], the abutments and the existing foundations of a deteriorated timber bridge originally located at the site could be reused due to the low self-weight of the FRP superstructure. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline
**No** & **Bridge** & **Location** & **Use** & **Length** & **Client** & **Producer** & **Contractor** \\ \hline
1 & Lightweight road bridge & (Untech, & 60 toss road traffic & 142.0 m & Prokail & FiberCon Europe & Heijmans \\
2 & Gray Beech & Beech, Belgium & Cyclists and pedestrians & 7.0 m & Farys & Composite Structures & Janson Bridging Belgium \\
3 & Manieros-friendly & Herten, on Softberg, & & & & & \\ bridge in wetland area & Denmark & Cyclists and pedestrians & Footpable: 30.0 m & Municipality Herming & Eberine & - \\
4 & Upstream and Downtown & Brugge, Belgium & & & & & \\ \(\ast\) & Canada Bridges & & & & & & \\ \(\ast\) & Cyclist and Pedestrian & Krimgen and Le, & Cyclists and pedestrians: 5\(\times\)m\({}^{2}\) & & & & \\ \(\ast\) & Bridge Krippel & The Netherlands & & 5 \(\times\) steps of service vehicles & 10.5 m & Switzerland \(\ast\) & FiberCon Europe & Hassonot \\
6 & Pedestrian bridge & & & & & & \\  & Oude Vignani & Gbert, Belgium & & & & & \\  & Spiering Bridge, & Maiden, & & & & & \\  & Mowable Road Bridge & The Netherlands & & & & & \\  & & & & & & \\ \(\ast\) & \(\ast\) & \(\ast\) & \(\ast\) & \(\ast\) & \(\ast\) & \(\ast\) \\ \(\ast\  
The low self-weight also has the advantage that the bridge can be easily transported in one or several pieces by road, water, or air and does not require heavy machinery during installation. The Krilpad bridge (bridge No. 5) [32] is situated in a nature reserve with a soft subsoil, making it impossible to transport any bridge, even FRP, over land to its destination due to the risk of environmental damage. Making use of the self-floating capacity of the sandwich-type FRP superstructure, it could be transported via the water without any additional aids. Then, the bridge was lifted into place onto a shallow foundation with minimal lifting equipment, again made possible by the low self-weight. The Oude Vismijn Bridge (bridge No. 6) [33] is located in the historic centre of Ghent, making the location inaccessible for heavy lifting machinery. In addition, the low self-weight also reduces the vertical action on the historic quays. In addition, in the case of a movable bridge, the use of a counterweight can be avoided. For the Spiering Bridge (bridge No. 7), a transparent design without a bascule pit was desirable.