Title: UHPFRC Precast slabs and field-cast joints of the Isabey- Darnley pedestrian bridge

Author(s): Charron, J.P.; Desmettre, C.; Cantin Bellemare, E.

Publication: Symposium Paper

Volume: 343

Issue:

Appears on pages(s): 494-503

Keywords: Ultra-High Performance Fiber Reinforced Concrete (UHPFRC); precast slabs; field-cast joints; pedestrian bridge; bending behavior.

DOI:

Date: 10/1/2020

Abstract:
A cast-in-place reinforced concrete footbridge built in 1967 suffering from extensive concrete spalling and rebar corrosion needed to be replaced. The use of a steel Pony-Warren truss combined with thin precast UHPFRC slabs linked by short UHPFRC field-cast joints was selected to build an innovative, durable and aesthetic footbridge minimizing impact on traffic during construction. Material rationalization allowed respective reductions of 64 % and 91 % of concrete and rebar volumes in the slab in comparison to a conventional reinforced concrete slab. The design process was completed with non-linear finite element calculations to obtain an adequate behaviour of the UHPFRC slabs and joints at service and ultimate limit states. A full-size proof specimen was then tested under positive bending moment and confirmed being adequate and fulfilling all the design specifications. Construction of the precast slab was successful and required less time than a conventional slab. The long-term performance provided by the UHPFRC slab will be followed up in the next decades.