Fatigue Behavior of Beam Diaphragm Connections With Intermittent Fillet Welds, Part I, Volume 2, Laboratory Fatigue Evaluation

This report is the second of a two-part, three volume final report presenting the findings of the research work that was undertaken to evaluate the behavior of Indiana highway bridges with diaphragm members welded directly to the web of the primary beams and girders. Fatigue cracks have been observed at several bridges that utilize the welded diaphragm connection. The seriousness of the cracking and the corresponding potential risk on the integrity of the bridge superstructure were assessed. Inspection and repair guidelines for bridges with the welded diaphragm connections were also developed as part of the research effort. This volume presents the results of laboratory fatigue tests that were conducted to evaluate the cyclic life of staggered and non-staggered diaphragm connections. The performance of three different repair and retrofit procedures on the cyclic life of the welded diaphragm connection was also studied. Analytical models of the cracked diaphragm connection were developed to study the expected response under field loading conditions. Recommendation for implementation of inspection, repair, and retrofit procedures are presented. The titles of the three volumes (Report Number in parentheses) are listed: Part I, Volume 1: Field Evaluation (FHWA/IN/JTRP-2001/10-I-1) Part I, Volume 2: Laboratory Fatigue Evaluation (FHWA/IN/JTRP-2001/10-I-2) Part II: Brittle Fracture Examination of the I-64 Blue River (FHWA/IN/JTRP-2001/10-II