Use of inaccurate methods of nondestructive evaluation and empirical acceptance criteria for bridge welds has resulted in unnecessary repair of welds and has permitted unsound welds to be incorporated in some bridges. Failure to apply accurate bridge weld quality acceptance criteria can significantly increase construction and maintenance costs or can lead to structural failures. Unnecessary weld repairs can generate harmful residual stresses and distortion and can often create new and more serious discontinuities.

Project 10-31 was initiated with the objective of developing needed improvements in bridge weld acceptance criteria. The research entailed collecting and evaluating existing literature and data, and performing analytical studies and laboratory tests to develop new data. During the course of the study, the technology for weld inspection and weld flaw quantification was also under development and was expected to play an important role in this research. However, the expected improvements in inspection and quantification technologies did not appear in time. Therefore, the acceptance criteria developed on the project was based on existing, knowingly inaccurate, inspection and quantification methods. The developed criteria are sufficiently flexible, however, so that they can be adjusted and improved as technology permits in the future.

The findings of the project and recommended acceptance criteria are included in NCHRP Report 335: Acceptance Criteria for Steel Bridge Welds.