Advanced Polymer Composites in the Civil Infrastructure The Evolution of Advanced Polymer Composites in the Civil Infrastructure Professor Len Hollaway Department of Civil Engineering University of Surrey

In the civil infrastructure the interest in composites commenced during the second world war with the introduction of radomes. Between 1940 and the late 1960s composites had rather a chequered career with one-off fun systems being made. By the late 1960s and into the 1970s composites were being taken more seriously by the industry and systems involving 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 by Maunsell 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

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)

Pins (b) (a) (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.

Reinforced concrete column FRP jacket - fibre in horizontal direction. Main direction of fibres (in the hoop 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).

Hybrid GFRP/CFRP/concrete rectangular GFRP Permanent shuttering Concrete GFRP CFRP Hybrid GFRP/CFRP/concrete rectangular Beam (after Meier & Trantafillou)

: Cross-section of Tee beam of composite/concrete construction 30 31.08 1.08 3.44 116.02 151.08 140 80 Two plies of +/- 45o GFRP manufactured from XLTM65U prepreg CONCRETE 4mm plywood plate Eight plies of 0/90o CFRP from XLTM65U prepreg   : Cross-section of Tee beam of composite/concrete construction

Concrete filled filament wound composite tubes The advantages of these systems are :- 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 To produce non-corrosive columns and piles. To enhance the ductility of the system.

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)

FRP materials have been successfully implemented 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 exist but it is scattered and not easily accessible. Effects of sustained stress need to be considered. Effects of environment on ambient cure systems need to be considered.

The end of the History Lesson