Evaluation of an epoxy-bonded steel plating system for strengthening bridge decks

A large number of existing bridge decks have been designed as continuous beams over supports, and rely on negative moment capacity near the supports to carry their loads. With the increase in the Australian national mass limit for bridges, the load capacity of bridges needs to be increased, which requires the negative moment capacity near the supports to be increased. This paper examines the durability of epoxy bonding of steel plates to the deck surface for this purpose. Steel plates bonded to concrete slabs were subjected to 200 cycles of heating/cooling and wetting/drying and one million cycles of simulated wheel loading pressure. The results of shear strength testing have shown that there are some differences in the failure modes and ductility between the cycled specimens and control specimens and it appears that the concrete-epoxy interface is adversely affected by the cycling process.