Improvement Of Seismic Capacity Of External Beam-column Joints Using Rectangular Spiral Shear Reinforcement
Free (open access)
C. Karayannis, G. Sirkelis & P. Mavroeidis
In this study the behavior of the external RC beam – column joints with continuous rectangular spiral reinforcement as shear reinforcement in the joint body is experimentally examined. The results of eight specimens are presented. The specimens are sorted into two groups based on the size of the column. The first group (Group A) comprises five specimens with a column cross-section equal to 20/20 cm; one specimen without shear reinforcement in the joint body, two with stirrups and two with rectangular spiral reinforcement as shear reinforcement of the joint. The second group (Group B) comprises three specimens; one without shear reinforcement in the joint body, one with one stirrup in the joint body and one with rectangular spiral reinforcement in the joint body. All specimens have suffered the same loading with increasing deformation and two full cycles at every step. Maximum displacements of the beam's free end in the loading cycles were ±6mm, ±20mm, ±40mm, ±60mm and ±80 mm for the 1st, 2nd, 3rd, 4th and 5th loading step, respectively. The results from the specimens reinforced with rectangular spiral reinforcement are compared with the results from the specimens reinforced with stirrups, in terms of maximum loading and energy absorption per step, and ductility capacity. From the observed responses of the tested specimens it can be deduced that the use of rectangular spiral reinforcement in the joint body significantly improved the seismic capacity of the examined external beam-column connections. Keywords: beam-column joints, spiral shear reinforcement.
beam-column joints, spiral shear reinforcement.