EXPERIMENTAL STUDY ON SEISMIC PERFORMANCE OF BEAM-COLUMN JOINTS WITH FIBER-REINFORCED CONCRETE IN JOINT CORE AND PLASTIC HINGE ZONE OF BEAM AND COLUMN END

Fiber-reinforced concrete (FRC) was used in this study to replace normal reinforced concrete (RC) for beam-column joints to improve the shear strength, deformability and energy dissipation capacity of beam-column joints. This was also to avoid severe reinforcement congestion and construction difficulties. Quasi-static tests of seven FRC beam-column joints and one RC beam-column joint were conducted with varying axial load ratio and stirrup ratio in joint cores, to analyse the failure modes, shear strength, deformability, energy dissipation capacity, shear stress-strain curves in joint cores and moment versus rotation curves in plastic hinge zones at beam ends. Experimental results indicated that FRC joints exhibited high shear strength and deformability before the main diagonal crack occurred at the joint core. As the test axial load ratio increased from 0.07 to 0.28, shear strength, energy dissipation capacity, shear strength and deformability of the joint core increased. As the stirrup ratio of joint core increased, shear capacity degraded slowly. The plastic hinge rotation capacity of beam ends was improved considerably.