This document discusses the seismic behavior of beam-column joints in reinforced concrete moment frames. It begins by introducing beam-column joints and their importance. It then explains that joints have limited strength and are vulnerable to damage during earthquakes. To prevent this, joints must be designed to resist earthquake effects. The document outlines how beams apply moments to joints during quakes and how this can cause diagonal cracking if the joint is not reinforced properly. It concludes that providing large column sizes or steel ties in the joint can prevent such cracking and damage.

1. SEISMIC BEHAVIOR OF
BEAM COLUMN JOINTS IN
REINFORCED CONCRETE
MOMENT RESISTING
FRAMES
PAVANKUMAR N
4BW13CSE08
2ND SEMESTER M.TECH
STRUCTURAL
ENGINEERING
GUIDE-
Mr. CHETHAN GOWDA R K

2.  Introduction to Beam-Column Joint
 Types & Importance of Beam-Column Joint
 Seismic Behaviour of Joints
 Reinforcing Beam-column Joints
 Provision for Horizontal ties in beams
 Anchorage of beam bars
 Exterior joint
 Interior Joints

3.  In RC buildings, portions of columns
that are common to beams at their
intersections are called beam-
column joints.

5.  Since their constituent materials have
limited strengths, the joints have limited
force carrying capacity.
 When forces larger than these are applied
during earthquakes, joints are severely
damaged.
 Repairing damaged joints is difficult, and so
damage must be avoided. Thus, beam-column
joints must be designed to resist
earthquake effects.

6. Under earthquake shaking, the beams adjoining
a joint are subjected to moments in the same
(clockwise or counter-clockwise) direction .
Under these moments, the top bars in the
beam-column joint are pulled in one direction
and the bottom ones in the opposite direction .

7. If the column is not wide enough or if the
strength of concrete in the joint is low,
there is insufficient grip of concrete on
the steel bars.
In such circumstances, the bar slips inside
the joint region, and beams loose their
capacity to carry load.

8. one diagonal length of the joint elongates and
the other compresses . If the column cross-
sectional size is insufficient, the concrete in
the joint develops diagonal cracks.

9.  Diagonal cracking & crushing of concrete can
be prevented in Joints.
Mostly, for this large column size is the most
effective.
 Another way is providing steel ties also
known as stirrups.
Reinforcing the beam column joint

15. Reference
Seismic Behavior of Beam Column Joints in
Reinforced Concrete Moment Resisting
Frames, Document No. :: IITK-GSDMA-EQ31-
V1.0 Final Report :: A - Earthquake Codes
IITK-GSDMA Project on Building Codes
How do beam-column joints in RC buildings
Resist Earthquakes? IITK-BMTPC Earthquake
tips20

16. Thank you