ACI 342R-16

This report provides a synthesis of the topic of flexural live load distribution and its applicability to concrete bridges. Flexural live load distribution is critical to describing how loads are transmitted through a bridge system. This report is intended to provide engineers, including load rating engineers, with basic guidance on the methods and tools available for determining live load distribution behavior of in-service bridges. Included in the report are descriptions, a brief history, and background of the flexural load distribution phenomena and a summary of design and analysis methods used to describe the phenomena in practice. A series of case studies are presented in the latter part of the report to serve as a comparison summary of commonly used live load distribution methods and their performance in describing the behavior of in-service structures. The report also provides performing bridge load ratings with a practical synopsis of the various methods available for determining the live load distribution factor. While this report is limited to flexural live load distribution, it provides the foundation for a future committee guide on the in-service evaluation of concrete bridges.