Tabitha G presents on retrofitting existing structures using fibre reinforced polymer (FRP) composites. FRP composites involve reinforcing fibres like carbon, glass or aramid embedded in a polymer resin matrix. Retrofitting techniques involve bonding the FRP composites to the exterior of structures to improve their strength. The process involves surface preparation, applying the FRP laminates, and curing. FRP retrofitting provides benefits like increased strength, corrosion resistance and durability. It can be used to reinforce structures in transportation, construction, marine and other fields, though specialized skills are required and it may not be suitable for all structures.

1. PRESENTATION BY:
Tabitha G (3NA11CV030)
NAVODAYA INSTITUTE OF TECHNOLOGY(NIT),
RAICHUR

2. CONTENTS
 Introduction
 Definition of Retrofitting and FRP
Composites
 Retrofitting by FRP
 Materials of FRP
 Retrofitting techniques and steps involved
 Properties and advantages retrofitting
 Field of application
 Limitations of retrofitting by FRP
 Conclusion
 Bibliography

3. INTRODUCTION
Structures
Design
Loads
Stressed members
Retrofitting process
Composite materials

4. RETROFITTING
 Retrofitting means the further
modification of anything after it has been
manufactured or constructed.
 Field of Structural Engg>Innovations>
PCC-RCC>Moisture>Idea>Retrofitting.
 By effectively doing retrofitting process
the strength of existing structures is
improved against adverse effects.

5. FIBRE REINFORCED
POLYMER (FRP)
 FRP is a composite material.
 A matrix of polymeric material that is
reinforced by fibres or other reinforcing
material.
 Composite material=(RESIN
MATRIX)+(REINFORCEMENT).
 Resin matrix = Polymer.
 Reinforcement = Fibres of either glass,
carbon & aramid.
 Fibers are the elements that carry load,
matrix distributes load & protects the fibres
from environmental conditions.

6. WHAT IS RETROFITTING
BY FRP?
 It is a technique of bonding external
FRP composites to the existing
structures of lower strength.
 Externally bonded FRP composites may
be laid on any RC structural member
like slab,beam,masonry wall or column it
can also be used for older relics.

7. MATERIALS OF FRP
 Basic constituent materials are:
 RESINS= EPOXY/
POLYSTER/VINYLESTER.
 REINFORCEMENT(FIBRES)=
CARBON/GLASS/ARAMID(KEVLAR).

8. VIEW OF FRP’S
EPOXYPOLYSTER VINYLESTER
RESINS
FIBRES
CARBONGLASS ARAMID

9. RETROFITTING TECHNIQUES
 Hand Lay-up/Spray-up.
 Resin Transfer Molding (RTM).
 Injection Molding.
 Reinforced Reaction Injection Molding
(RRIM).
 Pultrusion.
 Filament Winding Laminates.
 Centrifugal Casting.

10. STEPS INVOLVED IN
RETROFITTING
 Preparation of the Concrete Surface.
 Mixing Epoxy, Putty etc.
 Preparation of the FRP Composite
System.
 Application of the FRP Strengthening
System.
 Anchorage (if recommended).
 Ambient curing of the FRP Material.
 Application of Finish System.

11. VIEW OF RETROFITTING BY
FRP

12. PROPERTIES & ADVANTAGES
OF FRP RETROFITTING
 High strength/weight ratio.
 Design flexibility.
 Light weight.
 Corrosion resistance.
 Low maintenance/long term
durability.
 Tailored aesthetic appearance.
 Dimensional stability.
 Low thermal conductivity.
 Low installed costs.

13. FIELD OF APPLICATION
 TRANSPORTATION
 CONSTRUCTION
 MARINE
 CORROSION-RESISTANT
 CONSUMER
 ELECTRICAL/ELECTRONIC
 AIRCRAFT/DEFENSE

14. LIMITATIONS OF FRP
RETROFITTING
 Greater tooling design and
construction skills required.
 Higher tool cost.
 Reinforcement loading may be
difficult with complex parts.
 Inefficient for high rise buildings.
 Not suited for building rested on soft
soils.
 Handbook for design is done only for
earthquake rehabilitation but not for
other deteriorations.

15. CONCLUSION
 Retrofitting is the best way to strengthen the
existing structure than the entire replacement
of the structure.
 Retrofitting by available FRP materials works
cheaper in rehabilitation too.
 Retrofitting increases the life expectancy of the
structure.
 Retrofitting process will in mere future help in
saving our monumentary treasures.
 A large scope in this domain can help save
peoples lives in massive earthquakes were
harm to life is not because of earthquake but
because of collapse of structures.

16. BIBLIOGRAPHY
1. Strengthening and Rehabilitation of Civil Infrastructure Using Fibre
Reinforced Polymer (FRP) Composites by L C Hollaway, University of
Surrey, UK and J G Teng, The Hong Kong Polytechnic University, China.
2. Dumas, Pierre, M. Eng. Massachusetts Institute of Technology.
Rehabilitation of Civil Infrastructure (research paper).
3. Bull, D and Sivyer 2001, Z: Retrofit with FRP Composites- Holmes Culley
Technical Memorandum.
4. Wang Yung-Chih 2000; Retrofit of Reinforced Concrete Members Using
Advanced Composite Materials – Research Report 2000-3, Department of
Civil Engineering, University of Canterbury, ISSN0110-3326.
5. Priestley, M.J.N, Seible, F and Fyfe, E: 1992;Column Seismic Retrofit Using
Fiberglass/Epoxy Jackets – Proceedings 1st International Conference on
Advanced Composite Materials in Bridges and Structures, pp 287-298.
6. Handbook on retrofitting in sesmic effect by CENTRAL PUBLIC WELFARE
DEPARTMENT and INDIAN BUILDING CONGRESS in aid with INDIAN
INSTITUTE OF TECHNOLOGY MADRAS issue in 2007.
7. Structural design and drawing reinforced concrete and steel – N
KRISHNARAJU, University Press.