Experimental investigation of retrofitting techniques for steel bridge girders subject to fatigue failure

Fatigue failure is major concern for infrastructure due to the increasing number of steel structures reaching the end of their design life each year. Increased loadings, deterioration due to weathering, climate change and human error also negatively impact the design life. Rehabilitating steel bridge girders rather than replacing the existing structure can provide an option for an economical and sustainable future. This paper presents the results of an experimental study which implements a simple retrofitting technique to combat fatigue failure. The retrofitting technique is applied to girders which have incurred fatigue cracking within the bottom flange. Experimental tests are performed on a riveted tapered 120-year-old girder and a new prefabricated hot rolled girder. The results from the experimental tests showed that fatigue cracking within the bottom flange of girders can be easily rehabilitated to increase the girder’s capacity to that of their original design. By utilising this simple designed retrofitting technique, existing structures do not need to be replaced. The technique shown herein is a viable method for increasing the service life of steel girders providing for a sustainable future