Analytical Investigation on Behaviour of RC Framed Corner Joints

Abstract

Beam-Column joints in a reinforced concrete moment resisting frame are crucial zones for transfer of loads
effectively between the connecting elements in the structure. It has been observed that during earthquakes, Corner Joints
are under heavy distress due to shear in the joints which results in the collapse of the structure. The previous studies
have confirmed that corner joints subjected to opening moments are more critically influenced by the detailing of
reinforcement than those subjected to closing moments. In the first part of the study four frames with different
reinforcement detailing arrangement i.e. conventional L-type detailing arrangement (SP1), inverted U-type detailing
with diagonal steel at corner (SP2), inverted L-type detailing with splay steel (SP3) and overlapping U-stirrups type
detailing (SP4) were analyzed using ATENA 2D software. Based on the results from ATENA software in terms of
ultimate load, first crack load, crack initiation width and crack width at ultimate load, specimen SP3 was selected for
further investigations as this specimen performed better structurally. In the second part of study, the effect of different
sizes of chamfer at reentrant corner; the effect of different percentage of tension steel; effect of different percentage of
compression steel; effect of different spacing of shear reinforcement; effect of different percentage of splay steel; effect of
different grades of concrete; and effect of different percentage of grade of steel were observed on specimen SP3.