Seismic Retrofit of Bridge Joints in Central U.S. with Carbon Fiber-Reinforced Polymer Composites

摘要

The objectives of this study were 1) to investigate failure modes of reinforced concrete bridge beam-column subassemblies under seismic loads; and 2) to propose an economic and efficient retrofit scheme using composites. To fulfill these objectives, two test units, designated as Units 1 and 2, were retrofitted and tested. Unit 1 was retrofitted at different damage levels and Unit 2 was strengthened in its virgin condition according to nearly the same retrofit scheme. Test results indicate that the repair and retrofit schemes employed in the damaged or undamaged columns were equally efficient in preventing shear failure of the column. On the other hand, whereas repairing the damaged beam-column joint in Unit 1 was inefficient, retrofitting the undamaged joint of Unit 2 was successful. An analytical model was also developed to include the contribution of joint flexibility into the lateral response of the units. Test results along with the recommended procedures for seismic design and implementation of the retrofit schemes are presented and discussed in this paper.