Design, construction and structural response of a lightweight FRP footbridge

This paper presents the design, construction and structural response of a laboratory FRP footbridge. Pultruded elements, Glass-FRP profiles and Carbon-FRP strips, comprise the 10 m long simply supported structure, which linear mass is only 80 kg/m approximately. A value of L/200 (L being the length of the span) was the limit adopted for the long-term deflection at mid-span, and verifications at Ultimate Limit State were carried out according to the recommendations of the FRP manufacturer and the European Guideline to design FRP Structures. To construct the bridge, the following phases were completed: (i) bonding CFRP strips to the GFRP stringers, (ii) connecting the FRP elements, (iii) casting concrete at the support regions, and (iv) installing the deck. Once the construction finished, an experimental static and dynamic campaign was performed to assess the bridge structural behavior. As expected from the design stage, excessive vertical vibrations under different pedestrian actions (walking and bouncing) were measured.