Simplified flexural design approach of ultra high performance concrete bridge girders

Ultra high performance fibre-reinforced concrete (UHPFRC) is a newly developed concrete material that provides very high strength and very low permeability. The renewal of aging highway bridges and the construction of new bridges using ultra high performance concrete can yield structurally efficient long life bridges, which will require minimum maintenance and low life cycle costs. A simplified flexural design approach of UHPFRC girders and a comparative study of the structural efficiency of UHPFRC and conventional precast prestressed concrete girder bridges are presented in this paper, and to compare its structural efficiency to conventional slab-on- concrete girder bridges. The proposed design approach is consistent with the Canadian Bridge Design Code (CHBDC) and is based on the state-of-the-art design recommendations for UHPFRC and checked using a three-dimensional finite element analysis. It is found that the use of UHPFRC in precast/prestressed concrete girders can yield a reduction of up to two girder lines with smaller girder sizes when compared to conventional concrete girders bridge. UHPC results in a significant reduction in concrete volume that can reach 40%, which turn leads to a more efficient design of the superstructure and a significant reduction in the dead loads on the substructure, which is very important for the safety of aging bridge substructures.
8th International Conference on Short & Medium Span Bridges: 03 August 2010, Niagara Falls, Ontario, Canada