Design Approach for FRP Structures: A Focus on Thermal Design

Abstract

The adoption of FRP materials for the construction of new bridges has become a challenge to traditional bridge engineers who need to become familiar with the materials itself but also with the code to design efficient FRP structures. Today, there is various available FRP design guidelines all around the world and in Europe, thus, the CEN/TC 250 showed the willingness to merge these different documents into a new Eurocode standard.

The presented paper analyses the design approaches of the CEN Technical Report for FRP structures detailing the design of a pedestrian FRP bridge. This real footbridge was built in 2015, in France, by Janson Bridging Company (see Fig. 1).

It consists of a two-span bridge for a total length of 36 m and a width of 2,4 m. The bridge consists of a sandwich structure with two GFRP (glass fibre-reinforced polymer) skins at the top and bottom of the bridge and a GFRP-reinforced foam core. The bridge was designed in compliance with the CUR96 recommendations, which follows the limit state design procedure and which involves reduction factors depending on the exposure conditions. The aim of the exercice is to compare the different design approaches and highlight the most important aspects. Here a focus is made on the thermal design. The results show that the method proposed in this paper can be further used for studies on the temperature behaviour of other general FRP bridges and to supplement the background document of the TS.