The primary tasks of the current study are to: 1. Construct macro models using the pushover analysis procedure for a exterior beam-column joint able to predict the overall behavior, capacity and the modes of failure. 2. Studying the behavior of a CFRP retrofitted exterior beam-column joint constructing a macro model using the pushover analysis procedure in order to predict its overall behavior, capacity and the modes of failure. 3. construct a model of ten-multi-story structure using the pushover analysis procedure able predict its overall behavior. Safety of construction members against earthquake and its mode of failure 4. studying the need of using retrofitting withstand the equivalent static force calculated by response spectrum analysis for the building by retrofitting only the first story then, retrofitting two stories and so on, and predict the overall behavior for each case until the capacity of building reach the safe zone against the earthquake

1. Faculty of Engineering-Tanta University
Structural Engineering Department
Structure Project
Year 2017

3. What is beam-column joint?
 In RC buildings, portions of columns that are common
to beams at their intersections are called beam-column
joints.

4. Interior
Exterior
Corner

5. Joints transfer forces that are
present at the ends of the
members.
failure in a beam often occurs at
the beam-column joint making
the joint one of the most critical
sections of the structure.
Sudden change in geometry and
complexity of stress distribution
at joint are the reasons for their
critical behavior.

7. Objectives
 Construct macro models
using the pushover
analysis for a exterior
beam-column joint.
 predict the overall
behavior, capacity and
the modes of failure.
 Studying the behavior
of a CFRP retrofitted
exterior beam-column
joint
 construct a model of
tenmulti-story structure
using the pushover
analysis
 overall behavior. Safety
of construction members
against earthquake
 Studying two alternative
of retrofitting and chose
more economic
1
22 5
4
63

8.  During the past four decades, significant amount of research has been
conducted to investigate the behavior of RC beam-column joints.
Hwang and Lee (1999) had developed a new model for predicting the
shear strength of the exterior beam-column joints
under seismic loading; softened strut-and-tie
model (SST),
Ehsani and Wight, (1985) displayed the experimental results of six exterior
reinforced concrete beam-column joints
subjected to reversible cyclic loading. Studied
parameters at this research were the
flexural strength ratio
.

9. Chung and Shah
(1989)
investigated the effect of cyclic loading rate,
shear span-to-depth ratio, and stirrup spacing on
the bond performance of exterior steel
reinforced beam column joints
(Hakuto et al 2000) studied the influence of reinforcement detailing
on seismic behaviour of exterior and interior
beam-column joints. For the exterior beam-
column joints,
Ehsani and Wight (1985) studying the behaviour of exterior beam-column
joints taking into account the effect of transverse
beams and slabs.

10. Earthquake Behaviour of Joints
 under the action of the above pull-push forces at top and bottom ends
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.

12. 3O16
3O16
5O8 m
400x
400mm
2250mm
x
3000mm
2O8
2O12 2O12
5O8m
A
A
B B
250mm
250mm
4O12
sec B-B
3O16
3O16
400mm
250 mm
sec A- A
200 KN
P=??
Concrete dimensions,
Reinforcement details of
specimen
Joint model
P

13. Define hinges properites
Joint shear failure
Flexural failure of beam
Flexural failure of column
Shear failure of beam
shear failure of column

14. 0
2
4
6
8
10
12
14
16
18
20
0 5 10 15 20 25 30 35 40 45 50 55 60
Displacement (mm)
basereaction(KN)
Step 2
P=8.57 KN
D=2.57 mm
Step 3
P=16.97KN
D=4.9 mm
Step 4
P=17.67 KN
D=24.9 mm
Step 5
P=18.37 KN
D=44.9 mm
 Failure of connection occurred in column at load: P=18.6 KN
0
2
4
6
8
10
12
14
16
18
20
0 5 10 15 20 25 30 35 40 45 50 55 60
Displacement (mm)
basereaction(KN)
Step 6
P=18.6 KN
D=53.8 mm
results

15. 0
5
10
15
20
25
30
35
40
0 1 2 3 4 5 6 7 8 9 10 11 12
basereaction(KN)
By making retrofitting to column, the plastic hinge in column
is controlled
0
5
10
15
20
25
30
35
40
0 1 2 3 4 5 6 7 8 9 10 11 12
Displacement (mm)
Step 1
P=0
D=0.2 mm
Step 2
P=24.8 KN
D=7.14 mm
Step 3
P=35.9 KN
D=10.47 mm
 Failure of connection occurred in joint at load: P=35.9 KN

16. 920mm
1440mm
1700mm
Failure in column
capacity 23.2 KN
max D=45.7mm
Failure in column
capacity 30.4 KN
max D=38.5 mm
Failure in beam
capacity 39.6 KN
max D=82.8 mm
Retrofitting joint and column

17. 0
5
10
15
20
25
30
35
40
45
0 10 20 30 40 50 60 70 80 90
Displacement (mm)
basereaction(KN)
The result showed that :
 the failure occur in beam by retrofitting the joint and 25% from
column
 when failure occur in beam ,frame ductility and energy dissipation
increase
Without retrofitting P=18.6 KN
10% Column
P=30.4 KN
P=23.2 KN
20% Column
25% Column P=39.6 KN

18.  residential building (30m*6m) consists of 10
floor . there are 2 frames to resist earthquakes
forces with column cross section 300*700 mm
and beam cross section 300*700 mm
 fcu=25MPa
 fy=360MPa

19. 0
50
100
150
200
250
300
0 100 200 300 400 500 600
0
50
100
150
200
250
300
0 100 200 300 400 500 600
displacement (mm)
basereaction(KN)
step 1 2 3 4 9 12
p 73.3 103 162 176 248 256
D 50 65 115 130 397 510
Capacity = 256 KN
Seismic force = 309 KN

20. 1325 mm1060 mm530mm
Failure in beam
capacity 275.8 KN
Failure in beam
capacity 298.7 KN
Failure in beam
capacity 317.6 KN

21. case 1 case 2 case 3 case 4
Retrofitting without
joint +
530mm beam
joint +
1060mm beam
joint +
1325mm beam
Capacity
(KN)
256.8 275.8 298.7 317.6
Failure joint beam beam beam
Max
displacement
(mm)
547.2 486.6 485.4 484.9
0
50
100
150
200
250
300
350
0 50 100 150 200 250 300 350 400 450 500 550 600
Displacement (mm)
basereaction(KN)
Without retrofitting
10% beam
20% beam
25% beam

22. evaluating the previous cases by the performance
curves resulted from pushover analysis
Before retrofitting
After retrofitting

23. design
REPAIR AND STRENGTHENING TECHNIQUES FOR BEAM-COLUMN JOINTS
CFRP
Concrete jacketing

24. Costruction
3Ø16
3Ø16
REPAIR AND STRENGTHENING TECHNIQUES FOR BEAM-COLUMN JOINTS
CFRP
Concrete jacketing

25. REPAIR AND STRENGTHENING TECHNIQUES FOR BEAM-COLUMN JOINTS
CFRP
Concrete jacketing
Costruction

26. CFRP Concrete jacketing
Economy
Materal
cost
Time period
Construction
cost
Total cost
REPAIR AND STRENGTHENING TECHNIQUES FOR BEAM-COLUMN JOINTS
12600
5000
2400
60000
4 days
30 days
65000
15000

27.  Web-bonded CFRP-retrofitting technique can be used to
relocate the beam plastic hinging zone away from the
column face in RC ordinary moment resisting frames
 Use (CFRP) in repairing better than concrete
jacketing as it take short time and lower total cost .
 when failure occur in beam ,frame ductility and
energy dissipation increase

28. Thank you