NCHRP Research Report 908 presents guidelines for evaluating complete joint penetration (CJP) welds in steel bridges and proposes modifications to the American Association of State Highway and Transportation Officials (AASHTO)/American Welding Society (AWS) D1.5. The guidelines are based on comprehensive analytical and round robin testing programs that established the critical flaw size that would be considered rejectable for typical bridge CJP welds, and identifies best practices for improved flaw detection and flaw characterization. This report will be of immediate interest to steel bridge fabricators and engineers.
Inspection of welds in steel bridges is necessary to ensure the quality of workmanship during the fabrication and construction process and later on when the bridge is in service. There are two non-destructive evaluation (NDE) methods for evaluation of complete joint penetration (CJP) welds in steel bridges: radiographic (RT) and ultrasonic (UT). Recent advances in enhanced ultrasonic methods, including the development of phased-array ultrasonic technology (PAUT), allow for efficient detection and characterization of flaws with the option of automated data collection and imaging. Criteria for categorizing weld discontinuities as acceptable or unacceptable are codified in the AASHTO/AWS D1.5M/D1.5: Bridge Welding Code (BWC). However, these acceptance criteria do not reflect the full use of the capability of enhanced ultrasonic testing methods, and furthermore are not based on the effect of weld discontinuities on bridge performance (e.g., resistance to fatigue and fracture). In addition, some weld discontinuities that are not allowed according to BWC potentially not harmful and may not decrease service life. An updated acceptance criteria based on enhanced ultrasonic testing methods for evaluation of CJP welds in steel bridges was needed for fabricators and bridge owners.
The objectives of this research were to: (1) develop guidelines to evaluate complete joint penetration welds in steel bridges based on updated acceptance criteria and (2) develop proposed modifications to the BWC. The guidelines cover shop and field fabrication and in-service evaluation and include procedures for using enhance ultrasonic testing methods to evaluate CJP welds in steel bridges and pertinent acceptance criteria
Under NCHRP Project 14-35, Purdue University was asked to: (1) develop guidelines to evaluate complete joint penetration welds in steel bridges based on updated acceptance criteria and (2) develop proposed modifications to BWC. The guidelines addresses shop and field fabrication and in-service evaluation and include procedures for using enhanced ultrasonic testing methods to evaluate CJP welds in steel bridges and pertinent acceptance criteria.
A number of deliverables, provided as appendices, are not published in the report but are available here. These appendices are titled as follows: