Structural Concrete - Hassoun

840 Chapter 20 Seismic Design of Reinforced Concrete Structures
Effective joint
area, Aj
Joint depth = h
in plane of
reinforcement
generating shear
Effective
joint width = b + h
≤ b = 2x
x
Reinforcement
generating shear
b
Direction of
forces generating
shear
h
x
Note:
Effective area of joint for
forces in each direction
of framing is to be
considered separately.
Joint illustrated does not
meet conditions of
18.8.3.2 and 18.8.4.1
necessary to be
considered confined
because the beams
do not cover at least ¾
of the width of each of the
faces of the joint.
Figure 20.24
Effective joint area (A j
). Courtesy of American Concrete Institute
beam depth h beyond the joint face are permitted to be considered adequate for confirming that
joint face.
A j = joint depth × Effective depth
Joint depth = h (overall depth of column)
Effective joint width = overall width of column except where a beam frames into a wider
column.
{ }
(a) Beam width + joint depth
Effective joint width ≤ (b)Twice the smaller perpendicular distance
from longitudianl axis of beamtocolumn side
Column–girder connection (joint).Courtesy of Murat Saatcioglu and John Gardner