"John's Bridge"



Bob's fave bridge...sorry, Bob, couldn't resist! :jd:

Date: 030121
From: http://ens-news.com/

Environment News Service, January 21, 2003

Wharton State Park - The first all plastic vehicular bridge using
unreinforced I-beams and other components made from recycled plastics
is now in place in New Jersey.

The 42 foot, single lane fire equipment access bridge over the
Mullica River in Wharton State Park is strong enough to support a
loaded fire truck weighing 36,000 pounds.

The bridge is made from a novel composite polymer material developed
at Rutgers University. Post consumer recycled polymers, such as high
density polyethylene and polystyrene from consumer packaging, were
used to make the tough, stiff, inexpensive structural materials,
keeping these plastics out of landfills.

Neither of the constituent polymers, found in polystyrene cups and
polyethylene milk jugs, would be suitable for structural use by
themselves. A patented processing technology developed at the Center
for Advanced Materials via Immiscible Polymer Processing (AMIPP) at
Rutgers University combines the polymers to create a blended composite
material with great strength.

The process melts two or more polymers together, then extrudes them
to form a fine microstructure. The special properties of the material
result from the development of an oriented microstructure that gives
the material unexpected mechanical properties and enables it to be
used for bridge I-beams, railroad ties, boardwalk substructures and
decking, and numerous other applications.

The Wharton project is the first demonstration of this new bridge
building technology. The bridge was designed by McLaren Engineering, a
civil engineering design and consulting firm, and consists of large I-
beams supported by posts with smaller I-beams spanning between the
larger structures. Three-inch thick tongue and groove decking material
provides the road surface.

All bridge members are fabricated from a special formulation of
polyethylene and polystyrene by the Polywood Corporation. Construction
was conducted by a special engineering team headed by Professors
Thomas Nosker and Richard Renfree at Rutgers University.

The new bridge, completed in November 2002, is impervious to water
and weathering effects, is almost indestructible, and never needs the
painting or other maintenance common to steel or wooden structures.
Sunlight and other natural elements help form a thin protective
coating on the surface of the polymer composite, and give it a finish
that blends well with the natural surroundings.

In addition to bridge I-beams, the AMIPP Center at Rutgers is working
on a variety of advanced materials using similar technologies to those
used on the bridge I-beams. Included are structural materials for
automotive and aerospace applications, specialized membranes and
catalyst supports for the chemical process industry, and biomedical
materials such as a synthetic bone material that imitates real bone
when implanted in the body by promoting tissue growth through a porous
polymer network.

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