Repair of slab-column connections using CFRP

Abstract

Repair, strengthening and retrofit of reinforced and prestressed concrete members have become increasingly important issues as the World's infrastructure deteriorates with time. In the United States, a tremendous amount of repair work is required on concrete bridges to avoid continued deterioration and the eventual need to replace the structures. Buildings and bridges are often in need of repair or strengthening to accommodate larger live loads as traffic and building occupancies change. In addition, inadequate design and detailing for seismic and other severe natural events has resulted in considerable structural damage and loss of life, particularly in reinforced concrete buildings. Numerous buildings and bridges suffer damage during such events and need to be repaired. The use of Carbon Fiber Reinforced Polymer (CFRP) composite fabric bonded to the surface of concrete members is comparatively simple, quick and virtually unnoticeable after installation. In the United States, the use of composites has become routine for increasing both the flexural and shear capacities of reinforced and prestressed concrete beams. Earthquake retrofit of bridge and building structures has relied heavily on composite wrapping of columns, beams and joints to provide confinement and increase ductility. This paper presents the results of cyclic testing of three reinforced concrete slab-column connections. Each of the specimens is a half-scale model of an interior slab-column connection common to flat-slab buildings. The specimens are reinforced according to current