Emergency Repair of Damaged Bridge Columns using Fiber Reinforced Polymer (FRP) Materials

摘要

Recent large scale testing at the University of Nevada at Reno (UNR) has successfully demonstrated the emergency repair and complete rehabilitation of columns using carbon fiber reinforced polymer (CFRP) jackets. As part of a continuing emergency repair research program being funded by Caltrans, a two-span bridge meeting current seismic design guidelines was tested, repaired, and retested to failure. The columns of the most critical pier were first tested until the longitudinal steel showed clear signs of the onset of buckling. Loose concrete was removed and replaced with a fast set grout. In addition cracks were epoxy injected and the surface was prepared for CFRP wraps. The CFRP repair was completed and subjected to accelerated cure measures. The bridge was re-tested after only 2-days and 5-hours in order to demonstrate the speed at which the bridge could be put back into service following a major seismic event. After undergoing near fault ground motions, the specimen was subjected to a static push over test until a displacement ductility of approximately twelve (12) was reached. The normal curing time for CFRP is seven days. This paper will focus on the material aspects of CFRP repair, the Caltrans program, and will describe the results of UNR testing of the repaired model.