Abstract:
The new deflection criteria of the AASHTO load and resistance factor design (LRFD) bridge specifications are examined with respect to their potential impact on the serviceability and long-term integrity of deck-type highway bridges. The examination suggests that if the intent of these new criteria is implemented, the effective service life of reinforced concrete deck slabs may in some areas of the country become considerably less than 250,000 h (30 years). Today, this is the age by which many deck slabs have disintegrated to the extent that they must be funded and programmed for replacement. On the basis of the examination, it is urged that long-term superstructure flexibility research on aging reinforced concrete deck slabs be accomplished so that specification changes and bridge characteristics can be based on known consequences. Otherwise, unwary transportation administrators who adopt LRFD recommendations and abandon live load deflection limitations may find themselves owners of defective bridges that may have to be replaced rather than just redecked.
