NCHRP Research Report 1128: Load Rating of Segmental Bridges presents procedures for load rating of segmental bridges. The proposed recommendations were developed based on extensive review of the state of practice of the evaluation of segmental bridges and comprehensive analytical programs. The research findings will be used by bridge load rating professionals at state departments of transportation.

A segmental bridge is constructed in short sections or segments that are either precast or cast-in-place concrete. Segmental bridges were first built in the United States in the 1970s and have proven to be an efficient design for long-span bridges. The earliest segmental bridges were designed, constructed, and load rated using methods that were not codified by the American Association of State Highway and Transportation Officials (AASHTO) and differ significantly from the current AASHTO load and resistance factor design (LRFD), load factor rating (LFR), and load and resistance factor rating (LRFR) methodologies. As a result, the use of current AASHTO LFR and LRFR methodologies to load rate existing segmental bridges has resulted in a significant capacity reduction in comparison to the old load rating procedures. In addition, there are limited resources for owners and consultants to accurately load rate segmental bridges. There was a need to develop load rating procedures to accurately determine the load rating capacity of segmental bridges to ensure safety and mobility.

Under NCHRP Project 12-123, “Proposed AASHTO Guideline for Load Rating of Segmental Bridges,” Auburn University was asked to (1) develop procedures for load rating of segmental bridges, (2) propose revisions to the current segmental bridge evaluation and design requirements, and (3) develop rating examples with supporting training materials to demonstrate the proposed procedures and revisions. In addition to the proposed Guideline, the research team proposed draft language for consideration by AASHTO in the next update of The Manual for Bridge Evaluation and the LRFD Bridge Design Specifications for the rating of segmental bridges.

NCHRP Research Report 1128 is available at this link.