FHWA LTBP Summary—National Changes In Bridge Practices For Reinforcing Bars

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INTRODUCTION

This study was conducted as part of the Federal Highway Administration (FHWA) Long-Term Bridge Performance (LTBP) Program in conjunction with the National Concrete Bridge Council. The LTBP Program is a long-term research effort, authorized by the U.S. Congress under the Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users to collect high-quality bridge data from a representative sample of highway bridges nationwide that will help the bridge community better understand bridge performance.⁽¹⁾ The products from this program will be a collection of data-driven tools, including predictive and forecasting models that will enhance the abilities of bridge owners to optimize their management of bridges.

The LTBP Program is collecting field data from bridges constructed from 1960 to the present. Because the LTBP Program not only collects the data but also analyzes it, the data must be evaluated in its proper context. Nationally, bridge technologies have changed, and new innovations have arisen so that the state-of-the-art for bridge engineering has advanced. It is important to record when these innovations and changes in bridge technology occur in order to better interpret and understand why the performance data may differ for bridges built from 1960 to the present. For example, if a bridge built in 1965 is outperforming a bridge built in 1978 (or vice versa), it would be helpful to understand what innovations and changes in practice occurred between these two dates that could affect bridge performance.

This summary report discusses the changes in bridge practice—both technology changes and innovations—for reinforcing steel for concrete bridge members.