advanced polymer composites in the civil infrastructure structural composites research unit,...

Advanced Polymer Composites in the Civil Infrastructure

Structural Composites Research Unit, Department of Civil Engineering - Univ. of Surrey

The Evolution of

Advanced Polymer Composites

in the

Civil Infrastructure

Professor Len HollawayDepartment of Civil Engineering

University of Surrey



•In the civil infrastructure the interest in compositescommenced during the second world war with the introduction of radomes.

•Between 1940 and the late 1960s composites had rathera chequered career with one-off fun systems being made.

•By the late 1960s and into the 1970s composites werebeing taken more seriously by the industry and systemsinvolving load bearing and infill units were being produced. These were used in conjunction with skeletal frameworks made from steel or reinforced concrete.



In 1974 the first all composite GFRP structure using the

building block method was a classroom structure

conceived and erected by Lancaster County Council.

The classroom system was made by hand lay-up using:

•Intumescent resins in the laminate external surface.

•An integral skin phenolic foam on the inside surface.

•CSM glass/polyester composite system.



GFRP Composite Class Room System 1974 conceived by Lancashire C.C.



In the mid 1980s and into the 1990s the development of the first automated building block was undertaken byMaunsell Structural Plastics.

Using this system the following All Polymer Composite

structures were manufactured: 1. Aberfeldy Bridge

2. Bonds Mill Bridge

3. Two storey building – used as offices at the 2nd Seven Crossing.



Maunsell Plank and Box Beam Cross-section



Aberfeldy Footbridge Bridge



Opening ceremony of the Bonds Mill Lift-bridge Gloucestershire



Composite Bridge Decks

To replace conventional degraded deck systems in minimum time the development of durable lightweight easy installation systems have been produced in advanced composites.

The system may be used in two forms:

•Replacement for existing but deteriorated decks

•Used as new structural components on conventional or new supporting structural elements



An all composite bridge deck being developed by a European consortium (ASSET) - Section of ASSET deck unit (By kind permission of Mouchel Consultants)



Wickwire Run Bridge - Taylor County, West Virginia, USA (By kind permission of Creative Pultrusions Inc Alum Bank, PA.)



Upgrading and retrofitting of structures and structural units.

Structures may require to be strengthened for a number of reasons.

•Design deficiencies

•Inferior materials

•Poor construction, workmanship/management



There is a choice between strengthening [or demolition]

Flexural strengthening •Bonding a plate onto the soffit of the beam

•Wrapping with a carbon fibre pultruded plate of prepreg wrap.

Shear strengthening

•Bonding a plate onto the vertical sides

•Wrapping prepreg around the sides and soffits and if possible around the whole beam



Thin layer of separated concrete

Exposed plate endInternal steel rebars

Typical mode of plate separation for a shear span/beam depth ratio of 4.0

CFRP Plate



Prestressed carbon fibre/epoxy plate bonded to soffit of cast iron beam (By kind permission of Mouchel Consulting)



General view of Hythe Bridge (By kind permission of Mouchel Consulting)



(a) (b) (c)

Various systems for wrapping FRP composite on to the sides of a Tee RC beam.

(a) FRP wrapped entirely around the beam.

(b) FRP wrap in the form of a U (either with or without pin fixings depending upon bond requirements).

(c) FRP wrap bonded to the two sides of the beam.

Pins



FRP jacket -fibre in horizontaldirection.

Reinforced concretecolumn

Main direction of fibres (in thehoop direction)

Wrapping of prepreg composite around concrete column



Systems that combine advanced polymer composites with conventional materials, in particular, concrete.

The objective is to use the two materials to their best advantage. For instance:-

•Concrete is poor in tension

•Advanced polymer composite have high tensile strengths

•Concrete has a high compressive strength value

•Advanced Polymer composites have low compressive reactions because of buckling of the unit, (assuming unit is a thin plate).



GFRP

CFRP

Concrete

GFRP Permanent shuttering

Hybrid GFRP/CFRP/concrete rectangularBeam (after Meier & Trantafillou)



CONCRETE

Two plies of +/- 45o GFRP manufactured from XLTM65U prepreg

4mm plywood plate

Eight plies of 0/90o CFRP from XLTM65U prepreg

30

31.08

1.08

3.44

116.02151.08

140

80

: Cross-section of Tee beam of composite/concrete construction



•Concrete core prevents buckling of the hollow FRP tube.

•FRP tube confines the concrete and increases strength and ductility.

•The best characteristics of the individual materials are utilised. The system was developed for two reasons

1. To produce non-corrosive columns and piles.

2. To enhance the ductility of the system.

Concrete filled filament wound composite tubes

The advantages of these systems are :-



Section of Carbon fibre shell girder showing girder to deck connection (By kind permission of V. Karbhari and F Seible)



Kings Stormwater Channel Bridge Salton Sea, California, USA (By kind permission of V. Karbhari and Seible UCSD)



I-5/Gilman advanced technology bridge to link separate areas of the Campus at University of California, San Diego, USA

(By kind permission of V. Karbhari and F. Seible UCSD)



Challenges of FRP material in the construction industry

•FRP materials have been successfully implemented into infrastructure projects – but their long-term durability (50+ years) required to be investigated.•Substantial amounts of useful information do existbut it is scattered and not easily accessible.•Effects of sustained stress need to be considered.

•Effects of environment on ambient cure systemsneed to be considered.



The end of

the

History Lesson

advanced polymer composites in the civil infrastructure structural composites research unit,...

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