It is a part of retrofitting i.e. repair, renovation, strengthening. Retrofitting is the modification of existing structures to make them more resistant. Jacketing is the most popularly used method for strengthening of building columns. Jacketing consists of added concrete with longitudinal and transverse reinforcement around the existing column. It improves axial and shear strength of column and major strengthening of foundation may be avoided.

1. done
by
BALAMURALI.K
18TPCV006
Seismic Retrofitting of RC Building
with Jacketing and Shear Wall

2. Jacketing

3. INTRODUCTION
• It is a part of retrofitting i.e. repair, renovation,
strengthening.
• Retrofitting is the modification of existing structures to
make them more resistant.
• Jacketing is the most popularly used method for
strengthening of building columns.
• Jacketing consists of added concrete with longitudinal and
transverse reinforcement around the existing column.
• It improves axial and shear strength of column and major
strengthening of foundation may be avoided.

4. NECESSITY OF JACKETING
 The load carried by column is increased.
 When there is error in design.
 Deterioration of column due to weathering action.
 Dilapidation of column.
 Heavy damage due to other causes like
earthquake, fire etc.

5. ADVANTAGES OF JACKETING
 It increases the seismic capacity of column.
 Amount of work is less as foundation strengthening
does not required.
 It increases the shear strength of column.
 It also increases confinement of concrete in circular
columns.
 Steel jacketing does not increase significant weight of
column and also saves construction time (curing).

6. TYPES OF JACKETING
 Reinforced concrete jacketing
 Steel jacketing
 Fiber reinforced polymer composite jacket
 Jacket with high tension materials like carbon
fiber, glass fiber etc.

7. PROCEDURE OF RC
JACKETING
 It can be employed as a repair or strengthening
scheme.
 First prepare the surface of existing structural
member.
 Provide shear key and reinforcement around the
existing column.
 Bonding agent is applied over prepared surface
of existing column and concrete is casted.

8. SHEAR KEY
• Drill holes of specified
diameter and depth to
receive shear key.
• Clean the drilled holes by
blowing air.
• Inject epoxy bonding
paste in drilled holes to
fill it from ends to half of
the holes.
• Insert “L” shaped shear
key and allow epoxy to
cure.

9. FUNCTIONS OF SHEAR KEY
 Bond properly new concrete and old concrete
 It holds the main reinforcement in position
 Treat a monolithic column
 Whole section is effective
 Resist shear failure
 Improve shear resistance
 Reduce the sliding effect between new and
hollow column

10. REINFORCEMENT
• The longitudinal and
transverse
reinforcement as per
design are fixed around
the existing column.
• Reinforcement is
properly tied with shear
key using binding wire.

12. REINFORCEMENT

13. BONDING AGENT
 It is needed to properly bond new concrete with
old concrete.
 So a bonding agent should be applied to surface
of old concrete before casting of new concrete.
 Generally epoxy bonding paste is used as
bonding agent.
 FUNCTIONS:
I. Bond properly new concrete & old concrete
II. Treat a monolithic column
III. Whole section is effective

14. ADMIXTURE
 A hyper plasticizer admixture is used with new
concrete to increase the strength & workability.
 FUNCTIONS:
I. It creates the concrete flowable
II. Eliminates the difficulty of vibration
III. Increses the strength of new concrete

15. CASTING OF CONCRETE
• Formwork is
installed around the
existing column and
proper support is
provided to
withstand the newly
poured concrete.
• Finally concrete is
poured and curing is
done.

16. STEEL JACKETING
• Addition of steel often
applied in the form of
plates and jackets.
• Main advantage is it
does not add
significant weight to
structure in
comparison with
concrete and also it
saves curing time.
• Disadvantage is it
requires heavy
equipments to handle
and maintenance is

17. FRP JACKETING
 It is a fiber reinforced polymer composite jacket
used for strengthening.
 very effective for confinement & shear
strengthening
 FRP composites present advantages over a
traditional confinement technique.
 The cross section dimension of column does not
increase, which permits compliance with
architecture restraints.
 Due to light weight of FRP material, the
installation procedure is faster and easier.

18. FRP JACKETING

19. CASE STUDY 1: SEISMIC
RETROFITTING OF RC BUILDING
WITH JACKETING
 Source
The mexico Earthquake of September
19,1985_Typical cases of Repair and
Strengthening of concrete Buildings.
M. Jara, C. Hernanddez, R. Garcia, and F. Robles
Earthquake spectra, Vol. 5, No. 1, 1989.

20. Typical Features of the Building
 Number of Stories – eight stories with basement
 Lateral load resisting system – reinforced
concrete frames
 Floor system – two way slab with beams
 Foundation – grid foundation with retaining walls
around the Perimeter.
Features of Damages in Mexico Earthquake,
1979
 Minor cracks in beams and columns Retrofitting
Techniques Employed after Mexico Earthquake,
1979
 Addition of concrete shear wall in axis 2 and A.

22. BEHAVIOUR OF RETROFITTED BUILDING IN
MEXICO EARTHQUAKE, 1985
 Spalling of the concrete cover and buckled bar at
the interface of the walls and beam‐column joints
 Main reinforcement in the columns located at the
ground floor buckled and crushing of the concrete
core occurred.
 Most damaged columns were the columns
adjacent to the added walls.

23. RETROFITTING TECHNIQUES EMPLOYED AFTER
MEXICO EARTHQUAKE, 1985
 Minor cracks – Repaired by injecting epoxy resins
 Buckled longitudinal reinforcement, broken ties
and crushed concrete – Replacement of new
reinforcement welded with the existing bars and new
closed ties were placed.
 Severely damaged columns adjacent to added
walls – Retrofitted with encasing in concrete with
longitudinal and transverse reinforcements. The
surface was cleaned and moistened before the new
concrete was placed.
 Other columns – Retrofitted with wire mesh
 Damaged concrete wall added – Demolished and
replaced with new concrete Walls with 200 mm in
thickness.

24.  Walls with slight damage –injecting epoxy
resins and by increasing their thickness to 200
mm Added new walls along the axis 2, 5, 6, E and
A
 Foundation – The foundation grid was encased
to permit the anchorage to the new longitudinal
reinforcement.

25.  Expected Performance
Static and dynamic analysis was performed on the
original undamaged building, match to the
distribution of the damage observed accordingly.
 Retrofitted building has been analyzed with the
assumption of monolithic behavior between old
and new material.
 Results indicate no additional piles to the
foundation.

26. REFERENCES
 Ravishankar.K., Krishnamoorthy.T.S, " Structural Health
Monitoring, Repair and Rehabilitation of Concrete Structures",
Allied Publishers, 2004
 CPWD and Indian Buildings Congress, Hand book on Seismic
Retrofit of Buildings, Narosa Publishers, 2008.
 https://theconstructor.org/practical-guide/jacketing-
collarsstructure-retrofit-repair-strengthening/5829/
 http://www.iitk.ac.in/nicee/wcee/article/11_504.PDF
 https://www.youtube.com/watch?v=B6Ubl5W9WVE

https://www.google.co.in/search?q=column+jacketing&dcr=0&so
u
rce=lnms&tbm=isch&sa=X&ved=0ahUKEwiPtuDig7vWAhVCRY
8KHYpo
AVYQ_AUICigB&biw=1280&bih=645#imgrc=NTZ47bWybVuUM
M
 https://www.youtube.com/watch?v=aXP4oNzi6YM
 http://www.iosrjournals.org/iosr-
jmce/papers/Conf15010/Vol1/7.%2040-46.pdf

27.  White, R. N., “Seismic Rehabilitation of Non-Ductile Reinforced
Concrete Frames – A Summary of Issues, Methods, and Needs”,
Proceedings, Workshop on the Seismic Rehabilitation of Lightly
Reinforced Concrete Frames, Gaithersburg, USA, June 12 – 13, 1995,
National Institute of Standards and Technology, USA, pp. 39 – 71.
 Sinha, R. and Shaw, R., “The Bhuj Earthquake of January 26, 2001 –
Consequences and Future Challenges”, Report, Indian Institute of
Technology Bombay and Earthquake Disaster Mitigation Research
Center, Japan, 2001, pp. 90–97.
 Murty, C. V. R., Goel, R. K. and Goyal, A., “Reinforced Concrete
Structures”, Earthquake Spectra, Earthquake Engineering Research
Institute, USA, July 2002, Supplement A to Vol. 18, pp. 145-185.
 Aboutaha, R. S., Englehart, M. D., Jirsa, J. O. and Kreger, M. E.,
“Rehabilitation of Shear Critical Concrete Columns by Use of
Rectangular Steel Jackets”, ACI Structural Journal, American Concrete
Institute, January-February 1991, Vol. 96, No. 1, pp. 68 – 78.
 Mukherjee, A. and Joshi, M. V., “Seismic Retrofitting Technique Using
Fibre Composites”, The Indian Concrete Journal, The Associated
Cement Companies Ltd., August 2001, pp. 496- 502.
 Swamy, R. N., Jones, R. and Bloxham, J. W., “Structural Behavior of
RC Beams Strengthened by Epoxy Bonded Steel Plates”, The
Structural. Engineer, The Institution of Structural. Engineers, UK, 1987,
pp. 59 – 68.
 Bonacci, J. F. and Maalej, M., “Externally Bonded Fiber Reinforced
Polymer for Rehabilitation of Corrosion Damaged Concrete Beams”,
ACI Structural Journal, American Concrete Institute, September –
October 2000, Vol. 97, No. 5, pp. 703 – 711.

28. Shear Wall

29. Fig. 1 A reinforced concrete wall

30. RC STRUCTURAL WALLS
Known as shear walls
Designed to resist lateral forces
Excellent structural system to resist earthquake
Provided throughout the entire height of wall
Practicing from 1960s for medium and high rise
buildings (4 to 35 stories high)

31. Importance of Shear wall
 When shear walls are designed and constructed
properly and they will have the strength and
stiffness to resist horizontal forces.
 Lateral forces caused by wind, earthquake and
uneven settlement loads.
 Shear walls prevents rotation at joints.
 Shear walls are especially important in high rise
building subjected to lateral wind and seismic
forces.
 Shear walls are constructed to counter the effects
of lateral load acting on a structure

32. ADVANTAGES OF SHEAR WALLS
Provide large strength and stiffness in the
direction of orientation
Significantly reduces lateral sway
Easy construction and implementation
Efficient in terms of construction cost and
effectiveness in minimizing earthquake damage

33. PLACEMENT OF SHEAR WALLS
Located symmetrically to reduce ill effects of
twist
Symmetry can be along one or both the
directions
Can be located at exterior or interior
More effective when located along exterior
perimeter of building

34. PLACEMENT OF SHEAR WALLS

35. Reinforced concrete shear wall

37. A simplified drawing of a building with
shear walls

38. Precast Shear Wall, New
Zealand

39. Precast Shear Wall, USA

40.  A simplified drawing of a dual frame-wall structure
running in one direction showing floor slabs
supported by beams

43. Important points to be considered while locating shear walls

47. Types
 Reinforced and unreinforced,
 Single story or multi-storey,
 Solid or perforated,
 Rectangular or flanged,
 Cantilever or coupled, etc.
 Most commonly used shear walls have rectangular
or flanged configuration. Several types of shear
walls are shown in Fig. 1.

49. Perforated SW
 Often openings are required in shear walls for
functional necessity (e.g., doors and windows);
such walls are referred to as perforated (i.e., wall
with openings). The portion of a shear wall
between two adjacent openings is called a pier,
whereas, the segment of shear wall above the
adjacent openings is called a spandrel or a beam.

50. Efficiency of shear walls
 Efficiency of shear walls is described in terms of
rigidity (or stiffness)
 Solid shear walls are most efficient so it is highly
desirable.

51. Flanged Shear Wall
 Shear walls meeting each other at right angles
result in flanged configurations and are referred
to as flanged walls.
 In such cases, a portion of the intersecting wall
can be treated as a flange of the shear wall (e.g.,
as an I-section or a T-section). Such walls are
normally required to resist earthquake forces in
both principal directions of the building. Several
flanged configurations are shown in Fig. 2 above.

52. Flanged Shear Wall

53. Simple Comparison between
Ordinary Building
 One way to limit the sway of buildings and
provide stability is to increase the section sizes of
the members to create a rigid, moment-resisting
frame. However, this method increases storey
heights, thus increasing the building cost. It is
rarely used for more than 7 or 8 storeys.
 Another way is to provide stiff, shear resisting
walls. These can be external walls or internal
walls around lift shafts and stair wells (a core) or
sometimes both are provided.

54.  Monolithic shear walls are classified as short, squat or
cantilever according to their height to depth ratio.

55.  Generally shear walls are either plane or flanged in
section, while core walls consists of channel
sections.

56. CASE STUDY 2: SEISMIC RETROFITTING OF RC
BUILDING WITH SHEAR WALL
 Source
Seismic Retrofit an RC Building
Enrique Del VALLE CALDERON, Douglas A.
FOUTCH, Keith D.HJELMSTAD, Eduardo
FIGUEROA-GUTIERREZ and Arturo TENA-
COLUNGA
Proceeding of Ninth World Conference on
Earthquake Engineering, Tokoyo-Kyoto, Japan
(Vol.VII),1988

57. Typical Features of the Building
 Number of stories – twelve
 Lateral load resisting systems – non‐ductile reinforced
concrete frames
 Floor system – cast ‐in‐ place concrete joist beam
construction with 2.5‐inch slab
 Foundation system – mat foundation (2.4 m thick) on
concrete friction piles
Features of Damages in Mexico Earthquake, 1979
 Extensive damage to first four stories in transverse
direction
 The spandrel beams and columns in Frame 1 and 5
experienced diagonal cracking over much of their
length in the first floor.
 The medium column in the fourth storey of Frame 3
suffered cracking and crushing
 The foundation performed well

58. Retrofitting Techniques Employed:
 Cracked beams and columns – Repaired with
epoxy injection.
 The columns of Frames 1 and 5 – Encased in
steel through the forth storey level.
 Frame 1 and 5 – Braced steel frames were
attached on the outside of the building in E ‐W
direction.
Expected Performance
 Results indicate that the steel braced frames
attached to the building strengthened and they
stiffened the structure, moving its natural period
away from the predominant ground period of 2.0
sec.

60. CASE STUDY 3: SEISMIC RETROFITTING OF RC
BUILDING WITH SHEAR WALLS AND JACKETING
Typical Features of the Building
 Number of stories – Eight ‐storey reinforced
concrete apartment building
 Building dimension – floor area 245 m² and storey
height is 3.0 m above the foundation level,
including penthouse
 Design and construction – 1984
 Lateral load resisting systems – moment resisting
RC frames. A structural wall around the elevator
 Floor system – concrete slabs in the stories.
 Foundation system – strip foundation in both the
direction

61. Features of Damages in Adana – Ceyhan
(Turkey) Earthquake, 1998
 Building under moderate damage category.
 Extensive damage was observed in beams
especially between the first and fifth floors.
Retrofitting Techniques Employed:
 Damaged columns or columns lacking required
vertical load carrying capacity are jacketed.
 Where feasible, use of composite reinforced
polymer fabric is recommended.
 Infilling of appropriate frame bays by in situ
reinforced concrete Shear walls with proper
anchorage to the existing frame.

62. Expected Performance
 After adding the shear walls, vibration periods
have reduced.
 Naturally, the reduction in natural vibration
periods after seismic retrofit is due to increase in
the stiffness of buildings.

64. Reference
 Egyptian Society for Earthquake Engineering (ESEE) ,Regulations for
Earthquake-Resistance Design of Buildings in Egypt.,Cairo
,Egypt.,(1988).
 Hassaballa, A. E , Sobaih, M. E & A. R. A. Mohamed ,Sensitivity
Analysis in Estimating Seismic Hazard for Sudan., Proc., 14th European
Conference on Earthquake Engineering, 30 Aug.-3 Sept., 2010, Ohrid,
Republic of Macedonia.
 Jong-Wha Bai, Seismic Retrofit for Reinforced Concrete Building
Structures , Final Report ,. Consequence-Based Engineering (CBE)
Institute,. Texas ,2003.
 Murty .C. V. R . , The Seismic Performance of Reinforced Concrete
Frame Buildings with Masonry Infill Walls ,A Tutorial Developed by a
Committee of the World Housing Encyclopedia,(First Edition ,Publication
Number WHE,2006).
 Sobaih, M. E ;Hassaballa, A. E , & Ismaeil, M. A. ,Assessment of
Seismic Performance and Strengthening of Existing School Buildings in
the Sudan, International Journal of Engineering Research &Technology
(IJERT),ISSN:2278-0181, 2(6), 2013.
 Ismaeil, M. A., and Sobaih, M.E, A Proposed Methodology for Seismic
Evaluation and Strengthening

65. Thank you