Development of an index for concrete bridge deck management in Utah

The purpose of this research was to develop a new index for concrete bridge deck management in Utah. Data were collected in the summer of 2005 from 15 concrete bridge decks in Salt Lake City. Decks ranged from 2 to 21 years in age and were all constructed with epoxy-coated rebar. Data collected from visual inspection, sounding, Schmidt hammer testing, half-cell potential testing, and chloride concentration testing were analyzed with statistics, and age, cover, and half-cell potential were ultimately selected for inclusion in a new Utah Bridge Deck Index (UBDI), which was structured around a deduct system using a 100-point scale. Coefficients were selected primarily on the basis of the judgment of the researchers and the Utah Department of Transportation (UDOT) personnel involved in the research. Also, threshold values for maintenance, rehabilitation, and replacement (MR&R) options were specified to be the same as those associated with standard sufficiency ratings. The UBDI and corresponding MR&R recommendation were then provided for each of the tested bridge decks. In addition, consideration of the possibility of treatment applications led to required adjustments in the UBDI calculation; the treatment options that were considered include an epoxy seal, a high-performance concrete overlay, and an asphalt membrane overlay. Four case scenarios were developed to demonstrate the response of the revised UBDI equation to these treatments. Finally, as aids for Utah DOT personnel implementing this research, charts were created to facilitate rapid determination of the required number of half-cell potential and cover measurements for different levels of reliability and tolerance.