Cyclic behavior of exterior beam-column joints strengthened with precast slurry infiltrated fibrous concrete laminates

Abstract

Beam-column joint is an important component of a reinforced concrete (RC) moment resisting frame and should be designed and detailed properly, especially when the frame is subjected to seismic forces. Many of the existing structures located in the seismic prone zone were designed and built on the basics of earlier codes with inadequate ductile reinforcement detailing. At present, even though these structures are not deteriorated, they are structurally inadequate. Hence, it becomes necessary to upgrade these structures using most economical and reliable strengthening techniques. This paper presents the investigations carried out to study the cyclic behavior of exterior beam-column joints strengthened with precast slurry infiltrated fibrous concrete (SIFCON) laminates. A total of 12 specimens corresponding to four test series were cast and tested under cyclic loading to study the load-deformation behavior, ductility associated parameters, ultimate load carrying capacity and failure characteristics. 20 mm thick precast SIFCON laminates were used to strengthen the conventional RC and fiber RC beam-column joints. For laminates, the fiber volume fraction was 9%. The steel fibers used in the study were round crimpled fibers having 0.5 mm diameter with the aspect ratio 60.