This document discusses various civil engineering applications of composite materials. It provides examples of composite materials being used for new bridge structures, enclosures, bonding steel plates, bonding carbon laminates and fiber fabrics, cables, ropes, tendons, rods, and anchors. It also discusses research and manufacturing related to composites. Specific projects where composites were used are described, such as footbridges in the UK, a bascule bridge, bridge soffit enclosures, and bridges where steel plates or carbon laminates were bonded for strengthening. Advantages of composites include high strength, low weight, versatility in design, durability, and reduced need for maintenance compared to steel.

1. COMPOSITE
MATERIALS
CIVIL ENGINEERING APPLICATIONS

2. PREVIEW
 New Bridge Structures
 Enclosures
 Bonded Steel Plates
 Bonded Carbon Laminates
 Bonded Carbon Fiber Fabric
 Cables
 Rope
 Tendons
 Rods
 Anchors
 Research
 Manufacturing

3. NEW BRIDGE STRUCTURES
Aberfeldy Footbridge- UK
 Built on a Golf Course
 World’s first cable-stayed footbridge
 Constructed in 1992
 113m long with 63m main span
 All composite materials used for construction of this bridge

4. Contd..
Bonds Mill Bridge - UK
 Bascule vehicular traffic bridge
 Constructed in 1994
 27ft long and 14ft wide by 2.8ft deep
 Maximum loading capacity of a 40-ton truck
 Six-cell box composite girder used for the construction

5. ENCLOSURES
Second Severn Enclosure System - UK
 Constructed in 1993
 Bridge bottom soffit enclosure system
 40 psf is the design load with a L/120 deflection

6. BONDED STEEL PLATES
Giezenen Bridge - Switzerland
 Made of reinforced concrete dual-tied arch
 Consists of concrete hangers and Orthotropic
beam & slab deck
 102 ft span
 Constructed in 1980
 Steel plates bonded to all
transverse & longitudinal deck beams

7. Contd..
Koblenz/ Waldshut Railway Bridge - Switzerland
 Historical railroad made of Wrought Iron
 Built in 1859
 Constructed to increase capacity for double-deck commuter trains
 Method employed was to bond steel plates to cross-girders

8. BONDED CARBON LAMINATES
Co-op City Departmental Store - Switzerland
 Reinforced concrete floor slab
 Constructed in 1996
 CFRP Laminates –To allow floor cutouts for elevator shafts and
escalator openings

9. Contd..
Ibach Bridge – Switzerland
 748 ft long bridge
 Construction 1991
 Coring external box damaged tendon in 128 ft span
 16.4 ft x 1.75 in x 6 in CFRP Laminate plates bonded to box to
rectify the damage

10. Contd..
Oberriet Rhein Bridge Rhein River Switzerland-Austria
 Rehabilitation & LL capacity upgrade & bottom soffit strengthening
 Construction 1996
 3-Span Steel Girder Bridge (35ft-45ft-35ft)
 CFRP Laminate strips bonded to bottom of deck between main
girders in positive moment region

11. Contd..
Furstenland Bridge - Switzerland
 Multi-Cell box arch bridge
 Extensive corrosion of box
 Carbon Laminates bonded to lower portion of webs inside box
during removal and replacement of bottom box slab areas

12. BONDED CARBON FIBER
FABRIC
Hanshin Expressway - Japan
 Construction 1996
 Carbon sheet column retrofitting

13. Contd..
Hiyoshigura Viaduct – Japan
 Bridge deck strengthening for increase from TL20 to TL25 trucks
 Tonen tow sheet & Sho-bond CFRP bonding method

14. CABLES
Storchenbrucke (Stork Bridge) - Switzerland
 First cable-stayed road bridge
 406 ft Length with Pylon Height of 125 ft
 Construction in 1994-96; 2 of 24 CFRP cable stays

15. ROPE
AKASHI-KAIKYO Bridge - Japan
 7.531ft main span / 283ft towers
 Pilot rope for main cables

16. TENDONS
SUMITOMO BRIDGES - Japan
 Oyama Works – Sumitomo Construction Co, Ltd.
 Pre/post-tensioned demonstration
 Internal post-tensioned box – 10 TecvhnoraR 6 mm strands
 External post-tensioning – 7 TecvhnoraR 6 mm strands
 8 mm AFRP Bars for stirrups and deck reinforcement

17. Contd..
SCHIESSBERGSTRASSE Bridge - Germany
 174 ft Long by 32 ft Wide with 3.7 ft Depth
 Post-tensioned with 27 continuous parabolic HLV-Polystal tendons
 Comprised of 19 E-glass rods
 Continuously monitored-Optical Fiber Sensors

18. RODS
 Seismic Retrofit-Joint Restraint

19. ANCHORS

20. RESEARCH
 Structural rehabilitation with CFRP Laminates

21. Contd..
PWRI composite
Cable Stayed Bridge - Japan
 Demonstrate Feasibility of
Construction
 36 ft main span / 15 ft side
spans 6.5 ft wide
 4.4 tons total weight (22 psf)

22. COLUMN WRAPPING
RESEARCH
HIMEJI, Japan
 Seismic Column Retrofitting
 Carbon Fiber Jacketing – Hanshin Expressway
 Tarayca Cloth Sheets

26. Structural FRP Composite plate binding Comments
need/deficiency solution
Corrosion of reinforcement Replacement of lost Damaged concrete must
in reinforced concrete reinforcement by plates of be replaced without
equivalent effect impairing behavior of
plates
Inadequate flexural Design FRP composite plate Extent of strengthening
capacity in reinforced bonding solution to add tensile limited by capacity of
concrete elements concrete in compression
Safety net to cover Add plates, either stressed or Method appropriate with
uncertain durability of pre unstressed, to ensure safety segmental construction
stressed concrete
Lost pre stress due to Replace pre stress that has Need to ensure no
corrosion in pre stressed been lost with stressed overstress of concrete in
concrete composites the short term

27. Structural need/deficiency FRP Composite plate binding Comments
solution
Inadequate stiffness or Add external pre stress by means of a
serviceability of cracked stressed composite plate
reinforced concrete structure
Potential overstress due to Design composite reinforcement before
required structural alteration removing load bearing members
Avoidance of sudden failure Addition of either stressed or
by cracking of cast iron unstressed composite plate bonding to
the tensile face
Enhancement of shear External bonding of stressed plates or Web reinforcement
capacity by web reinforcement techniques little
researched

28. Overview of Hybrid Strengthening work

29. Detail of connection of the two beams

30. Advantages of epoxy resin over other
polymers
The advantages of epoxy resins over other polymers as adhesive
agents for civil engineering use can be summarized as follows:
 High surface activity and good wetting properties for a variety of
substrates.
 May be formulated to have a long open time (the time between
mixing and closing of the joint).
 High cured cohesive strength, so the joint failure may be dictated by
the adherent strength, particularly with concrete substrates.
 May be toughened by the inclusion of a dispersed rubbery phase.

31. Contd..
 Minimal shrinkage on curing, reducing bond line strain and allowing
the bonding of large areas with only contact pressure.
 Low creep and superior strength retention under sustained load.
 Can be thixotropic for application to vertical surfaces.
 Able to accommodate irregular or thick bond lines.
 Formulation can be readily modified by blending with a variety of
materials to achieve desirable properties.

32. Advantages of FRP Composite
Plate Bonding
Strength of plates: FRP composite plates may be designed with
components to meet a particular purpose and may comprise varying
proportions of different fibers. The ultimate strength of the plates can
thus be varied, but for strengthening schemes the ultimate strength of
the plates is likely to be at least three times the ultimate strength of
steel for the same cross-sectional area.
Weight of plates: The density of FRP composite plates is only 20% of
the density of steel. Thus composite plates may be less than 10% of
the weight of steel of the same ultimate strength. Apart from transport
costs, the biggest saving arising from this is during installation.
Composite plates do not require extensive jacking and support systems
to move and hold in place. The adhesives alone will support the plate
until curing has taken place. In contrast, fixing of steel plates
constitutes a significant proportion of the works costs.

33. Transport of plates: The weight of plates is so low that a 20 m long
composite plate may be carried on site by a single man. Some plates
may also be bent into a coil as small as 1.5 m diameter, and thus may
be transported in a car or van without the need for Lorries or
subsequent craneage facilities. The flexibility of plates enables
strengthening schemes to be completed within confined spaces.
Versatile design of systems: steel plates are limited in length by their
weight and handling difficulties. Welding in situ is not possible, because
of damage to adhesives, and expensive fixing of lap plates is therefore
required. In contrast, composite plates are of unlimited length, may be
fixed in layers to suit strengthening requirements, and are so thin that
fixing in two directions may be accommodated by varying the adhesive
thickness.

34. Easy and reliable surface preparation: Steel plates require
preparation by grit blasting, followed by careful protection until shortly
before installation. In contrast, the ROBUST project has demonstrated
that composite plates may be produced with a peel-ply protective layer
that may be easily stripped off just before the adhesive is applied.
Reduced mechanical fixing: Composite plates are much thinner than
steel plates of equivalent capacity. This reduces peeling effects at the
Ends of the plates and thus reduces the likelihood of a need for end
fixing. The overall depth of the strengthening scheme is reduced,
Increasing head-room and improving appearance.

35. Durability of strengthening system: There is the possibility of
corrosion on the bonded face of steel plates, particularly if the concrete
to which they are fixed is cracked or chloride contaminated. This could
reduce the long term bond. Composite plates do not suffer from such
deterioration.
Improved fire resistance: Composite plates are a low conductor of
heat when compared with steel, thus reducing the effect fire has on the
underlying adhesives. The composite itself chars rather than burns and
the system thus remains effective for a much longer period than steel
plate bonding.

36. Reduced risk of freeze/thaw damage: There is theoretical risk of
water becoming trapped behind plate systems, although this should not
occur if they are properly installed. In practice, this has not been found
to be a problem. However, if water did become trapped in this way, the
Insulating properties of the composite materials would reduce the risk
of disruption of the concrete due to freeze/thaw. Loss of bond would
also be evident by tapping the composite, but would be more difficult to
detect with steel.
Maintenance of strengthening system: Steel plates will require
maintenance painting and may incur traffic disruption and access costs
as well as the works costs. Composite plates will not require such
maintenance, reducing the whole life cost of this system.

37. Reduced construction period: Many of the practical advantages
described above combine to enable composite plates to be installed in
greatly reduced time periods when compared with steel plates. As well
as lower contract costs, the traffic delay costs are minimized.
Installation from mobile platforms becomes possible and it may become
practicable to confine work within such restraints as limited railway
possessions or night-time working.
Ability to pre stress: The ability to prestress composites opens up a
whole new range of applications for plate bonding. The plate bonding
may be used to replace lost prestress and the shear capacity of
sections will be increased by the longitudinal stresses induced.
Formation of cracks will be inhibited and the serviceability of the
structure en-hanced. Strengthening of materials such as cast iron also
becomes more practicable.

38. Disadvantages of FRP Composite
Plate Bonding
Cost of plates: Fiber reinforced composite plates are more expensive
than steel plates of the equivalent load capacity. However, the
difference between the two materials is likely to be reduced as
production volumes and competition between manufacturer’s
increases. Comparison of total contract costs for alternative methods of
strengthening will be based on labor and access costs as well as
material costs. Open competition has already shown that FRP
composite plate bonding is the most economic solution in virtually all
tested cases, without taking into account additional advantages such as
durability.

39. Mechanical damage: FRP composite plates are more susceptible to
damage than steel plates and could be damaged by a determined
attack, such as with an axe. In vulnerable areas with public access,
the risk may be removed by covering the plate bonding with a render
coat. Fortunately, if damage should occur to exposed FRP composite
plate, such as by a high load, repairs can be undertaken much more
easily than with a steel plate. A steel plate may be dislodged, or bond
broken over a large area, which would damage bolt fixings and
necessitate complete removal and replacement.
However, with FRP composite plate bonding the damage is more likely
to be localized, as the plate is thinner and more flexible. With FRP
composite, the plate may be cut out over the damaged length, and
a new plate bonded over the top with an appropriate lap.

40. CONCLUSIONS
 Fiber reinforced composite plate bonding offers significant
advantages over steel plate bonding for the vast majority of
strengthening applications.
 No construction or repair method involving structural analysis and
deterioration mechanisms can be said to be completely understood,
including all of those currently in everyday use. However, FRP
composite plate bonding has been sufficiently researched to enable the
techniques to be applied confidently on site, providing care is taken.
 The method of FRP composite plate bonding is here to stay and is
already being actively marketed. The number of applications worldwide
is set to grow very fast. The challenge is to ensure that these
applications take full account of the current state of knowledge. The
benefits must not be put at risk by inappropriate or badly detailed
applications under-taken by the inexperienced.

41. Future Composite Applications
 Internal Structural Aircraft Components
 Human Body Structural Components
 Precision Dimensional Measurement Devices
 Concrete Reinforcement in Buildings
 Bridge Construction Components
 Automotive Body Components
 Components for Automotive Engines
 Utility Poles
 Production Tooling

42. THANK YOU