The Minnesota Department of Transportation (Mn/DOT) documented the appearance of excessive cracks in the reinforced concrete pier cap overhangs of State Highway Bridges 19855 and 19856. As a part of this study, the ultimate capacity of the pier cap overhangs was estimated by comparing predicted capacities calculated using standard design specifications to experimental results published in the worldwide literature. It was determined that the ultimate capacity of the pier cap overhangs was more than sufficient to assure that a cracked, but undeteriorated, pier cap is not prone to structural failure. An estimate of the initial cracking load of the pier cap overhangs was also created to determine what changes to pier cap design would be required to prevent future overhangs from cracking. It was determined that the depth of the overhangs would have to be increased by approximately 20% to prevent them from cracking. The changes to pier cap overhang design required to prevent cracking or meet recommendations to reduce crack widths may not be economically feasible. Therefore, other methods for controlling crack widths must were examined. An experimental study was conducted to investigate the use of externally bonded (EB) FRP sheets and near surface mounted (NSM) FRP tape for shear strengthening of reinforced concrete beams. This report describes the experimental program, presents the results of the study, and discusses the outcome of that investigation.
