AN EXPERIMENTAL STUDY ON INFLUENCE OF BENDING RADIUS OF MAIN TENSILE BARS ON STRESS TRANSMISSION IN REINFORCED CONCRETE KNEE JOINT

Abstract

 In Japan, the stress transmission of RC beam-column joints is calculated differently depending on their type of joint. In interior joints, main bars are continued through the joint panel both vertically and horizontally. However, main bars in knee joints are not continued in general. Additionally, since there is slight vertical load on knee joints from above, sufficient bond between concrete and main bars cannot be expected and that makes the joint panel relatively easy to break under stress transmission. In the previous studies (Hotta and Nishizawa 2012), it was concluded that the sufficient inside radius of the main tensile bars continuously arranged through the panel from beam to column improved bearing strength between curved bars and concrete, and also improved shear strength of the panel as a result in the joint panel subjected to closing force. The objective of this following study is to show the influence of the inside radius of the main tensile bars which are separately arranged in the joint panel in line with a practical design under stress transmission by conducting closing and opening load.