Trrl Lr 629

After four years of normal trafficking, cracking occured in welded connections on an experimental orthotropic bridge deck panel. These connections were fillet welds between the trapezoidal stiffeners and the cross-beam, the stiffeners being fitted between cross-beams. Initial investigations showed that the cracking was due to fatigue of the weld metal accelerated by factors attrributed to the poor standard of fabrication of the deck panel. Further investigation was required to establish the performance under traffic loading because this stiffener design is typical of that used in bridge deck construction. Laboratory fatigue tests were carried out on spicemens containing a single stiffener and on a full size deck panel. These were made to good commercial standards and careful attention was paid to the measurement of fit-up between the parts of the test specimens and to the residual strains caused by welding. The tests confirmed that the design of this type of stiffener to cross-beam connection bust be assessed for fatigue under traffic loading