PSI - Issue 64

Maciej Kulpa et al. / Procedia Structural Integrity 64 (2024) 1339–1346 Kulpa / Structural Integrity Procedia 00 (2019) 000 – 000

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2.3. FRP deck panels The FRP deck panels were designed assuming the InfraCore Inside system solution (Veltkamp, 2019). The sandwich panel comprises two GFRP outer laminates that surround a foam core. The 13 mm thick laminates are made of E-glass fibres and polyester resin. The core is reinforced with 8 mm thick vertical composite ribs that run in the transverse direction in relation to the bridge axis. All composite parts (outer laminates and vertical ribs) are monolithically connected to each other using continuous reinforcing fibres. The outer laminates and longitudinal inner ribs are made from the same base materials, in this case a non-pleated fabric running through the upper laminate, inner ribs and lower laminate. This solution provides a durable fibre-reinforced connection between the laminates and the ribs, eliminating the risk that the outer laminate is peeled off the core. The panels were made as fully prefabricated using the VARTM (vacuum assisted resin transfer moulding) method.

Fig. 3. View of the structure and panel components

38 panels with a plan dimension of 2 × 3.85 m and a thickness of 12 cm were used to cover the entire length of the reconstructed steel structure. The fastening system was based on 4 clamps for each panel. The panels were placed on elastomer pads on the upper flanges, resulting in local and global separation effects and non-composite action between the deck and the main girders. This combination guarantees long-term, trouble-free operation (Olivier et al., 2023). After panel installation, the deck equipment was placed: the thin surface and drainage system (Fig. 3). 2.4. SHM monitoring system Due to the relatively new FRP deck system used in the reconstruction, it was decided to implement a monitoring system for the control of the deck under service load during the service life. Based on the previous positive experience with monitoring of FRP composite structures (Kulpa et al., 2021), the use of distributed fibre optic sensing (DFOS) technology was chosen, in which continuous optical fibres (fibre sensors) are embedded or fixed to a structure to measure its response, mainly strains, using an intererogator unit (reflectometer). The use of continuous fibres rather than spotted sensors installed at intervals allows for precise, high-spatial-resolution monitoring of entire structure.