Accounting for the effect of rebar depth variation is one of the most important and challenging tasks to accurately assess the condition of reinforced concrete elements using ground penetrating radar (GPR) technique. In current practices, this task is performed on the individual basis, as for each bridge deck a unique depth correction model is derived from the GPR data collected on it. It is fo...

Two different design problems are commonly encountered by highway bridge maintenance engineers: the upgrade of existing members to handle increased load demand, or the repair of bridge members which have experienced impact events due to overheight vehicles. This paper shows that through the use of carbon fiber reinforced (CFRP) materials highway bridge girders can be effectively strengthened or...

60 A practical approach to the optimal design of precast, prestressed concrete highway bridge girder systems is presented. The approach aims at standardizing the optimal design of bridge systems, as opposed to standardizing girder sections. Structural system optimization is shown to be more relevant than conventional girder optimization for an arbitrarily chosen structural system. Bridge system...

Résumé NRCC 44246 National Research Council Canada Conseil national de recherches Canada

This paper deals with the economic optimization of reinforced concrete box frames used in road construction. It shows the efficiency of four heuristic algorithms applied to a problem of 50 design variables. Heuristic methods used are the random walk and the descent local search. The metaheuristic methods are the threshold accepting and the simulated annealing. The four methods have been applied...

This paper presents the development and experimental validation of a multi-hazard bridge pier concept, i.e., a bridge pier system capable of providing an adequate level of protection against collapse under seismic and blast loading. A multi-column pier-bent with concrete-filled steel tube (CFST) columns is the proposed concept, and the adequacy of this system is experimentally and analytically ...

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The adequacy of the existing design provisions for concrete-filled steel pipes subjected to axial forces and flexure is reviewed by comparing the strengths predicted by the CAN/CSA-S16.1-M94, AISC LRFD 1994, and the Eurocode 4 1994 codes and standards against experimental data from a number of investigators. New proposed design equations are then developed, in a format compatible with North Ame...