Use of adhesives to retrofit out-of-plane distortion at connection plates

Before 1985, it was common practice to avoid welding floor beam and diaphragm connection plates to the tension flange of steel bridge girders. This practice often resulted in web-gap cracking due to out-of-plane distortion of the girder web. The most widely applicable and accepted retrofit method is to attach the connection plate rigidly to the flange. There was an investigation of a retrofit option that used a two-part epoxy cured at room temperature to join a small length of 3/4-in.-thick steel angle shape to the tension flange and the connection plate. Field tests conducted on two multiple-girder bridges indicated that significant out-of-plane stress ranges were typically reduced by at least 40% after retrofit. For details that have the potential for web-gap cracking but have not yet exhibited detectable cracks, the 40% reduction in stress range is likely enough to eliminate the possibility of future web-gap cracking effectively.