FRP Grating Case Study | Bridge Pedestrian Maintenance Walkway — ZeAllgrate

A 320 m highway and rail bridge required a replacement pedestrian maintenance walkway along its lower chord, used by inspectors and maintenance crews to reach bearings, expansion joints and the underside of the deck. The previous steel walkway had corroded badly from road-deck de-icing salt and rain splash, and — because the bridge carries an electrified commuter rail line alongside the highway — the steel walkway created an electrical hazard when live-line work was performed nearby. The walkway also had to span the bridge's transverse floor-beam spacing without intermediate supports, to avoid obstructing the maintenance path.

Engineering specified 50 mm pultruded FRP grating for long spans and a non-conductive walking surface, with UV-stabilized resin and all stainless hardware. Client identity is kept confidential; the project is described as Confidential Client, a transportation infrastructure authority.

ZeAllgrate supplied 420 m² of 50 mm ZeAll Pultruded FRP grating in UV-stabilized vinyl ester, with grit-top surface across the full walkway. Panels were fabricated to the bridge's floor-beam spacing and pre-drilled for SS316 brackets, so crews could install them from a suspended platform under the bridge without on-site cutting. The 50 mm bearing-bar depth spans the 1.5 m transverse beam spacing without intermediate supports, keeping the maintenance path clear.

The non-conductive walking surface means inspectors working near the electrified rail cannot become a conductive path to ground, and the UV-stabilized vinyl ester resists the de-icing salt that destroyed the previous steel walkway. Because FRP is roughly 75% lighter, the existing bridge chord required no structural reinforcement.