New systems of precast bridge decks made with ultra-high performance fiber reinforced concretes

Abstract : The presentation will focus on the development of various precast bridge slabs including ultra-high performances fiber reinforced concrete (UHPFRC), and a UHPFRC field-cast connection adapted for these precast slabs. Phase 1 of the project provided three innovative bridge slab designs: a reference slab made of high performances concrete (HPC), a hybrid slab incorporating high and ultra-high performances fiber reinforced concrete (HPFRC and UHPFRC), and a UHPFRC slab. Test conducted in laboratory demonstrated that slabs made with UHPFRC fulfilled easily requirements of crack openings and ultimate strength specified in the Canadian Bridge Code. The UHPFRC field-cast connection developed in Phase 2 of the project was combined with precast slabs developed in Phase 1 and tested in laboratory. The tests confirmed that HPC slabs linked with the UHPFRC connection provided similar maximum crack openings, stiffness and ultimate strength as the equivalent cast-in-place HPC slab. Moreover, utilization of the UHPFRC connection between precast hybrid slabs provided smaller crack width and superior ultimate strength than specifications of the Canadian Bridge Code. Parametric numerical studies showed the improved mechanical performance of precast deck including UHPFRC component detailed previously. The Isabey-Darnley pedestrian bridge build in 2016 with UHPFRC precast bridge slabs and field-cast joints developed in this project will be described.

Bio : Jean-Philippe Charron is Full Professor at the Department of Civil, Geological and Mining Engineering of Polytechnique Montreal and head of the Group for Research in Structural Engineering. He completed a PhD at Laval University (Canada) on early-age behavior of concrete and cracking mitigation in 2002 and a post-doc at EPFL (Switzerland) on the rehabilitation of infrastructures with ultra-high performance fiber reinforced concretes (UHPFRC) in 2004. Since 2007, he is leading industrial research projects on the development of new bridge components and bridge repairs with high and ultra-high performance fiber reinforced concretes (HPFRC and UHPFRC) funded by the Natural Sciences and Engineering Research Council of Canada, major bridge owners and construction companies. He is member of ACI Committees 239 on UHPFRC and 544 on FRC, he is also involved in the development of the Canadian Bridge Design Code. His research interests include development and characterization of fiber reinforced concretes (FRC), design and rehabilitation of bridges with FRC, and durability of concretes under loads.