EXPERIMENTAL STUDY OF RC BEAM-COLUMN JOINT RETROFITTED BY BFRP GRID WITH HIGH STRENGTH MORTAR

Abstract

The reinforced concrete (RC) beam-column joint is a critical member of the building. Its failure can make the structure collapse abruptly. The failure of joints mostly occurred in the structure built before the 1970s because of poor design and inadequate reinforcement detailing. To date, numerous research has been conducted to enhance the performance of the joint in terms of failure mode, strength, and ductility by externally retrofitting using bonded fiber-reinforced polymer (FRP) technique. Nonetheless, using bonded FRP technique encounters some drawbacks such as debonding and inadequate performance under moist and flammable environments. To overcome this, epoxy is replaced by a cementitious matrix. In this study, a RC beam-column joint is fabricated in 2/3 scale following an existing structure. The specimen is retrofitted using Basalt Fiber Reinforced Polymer (BFRP) grid with the combination of the cementitious matrix using high strength mortar. The dimension of the retrofitted specimen is intentionally kept the same by taking out the concrete cover where the cementitious matrix is employed. As the result, the overall performance of the specimen is improved. The specimen becomes stronger and can withstand longer applied displacement before it collapsed. © 2022 ISEC Press.