There are occasions when an existing concrete bridge deck needs local strengthening to improve its serviceability under current traffic loading. The use of steel plates bonded to the surface as additional reinforcement can sometimes be an economically attractive solution. An example of the use of this technique to improve the working load capacity of a group of bridges at a motorway interchange is described. Full-scale loading tests on one of the bridges before and after strengthening demonstrated that the required improvements had been achieved. Results of associated laboratory tests are also given, with some indication of where further research may lead to improvements in performance for future applications. Until the long term durability of bonded joints in this type of construction has been established the technique is not recommended for general use but can be considered for certain applications. Exposure tests are being carried out to determine whether there is likely to be any deterioration of bond efficiency with time. (Author/publisher)
Abstract