I have a more recent map distributed this year. On that map the bridge is entitled..."Polystyrene carbonate plastisol bridge number 001."
Has a nice ring to it right? I am holding my breath for when they make the covered bridge walkway at Bamber Lake out of plastic.
Bob,
"Plastic Wood" is the building material of the future. We are not growing enough "high--quality" wood to satisfy our burgeoning needs. It is not sensible, either for economic, or for a wide variety of environmental reasons, to buy wood from abroad...
The boneheads who have the "clout" to make the appropriate policy are, as usual, caving--in to the pressures of the lobbyists for the "container industry." Oil that can be put to better use elsewhere is being used for one--use food packaging, and for those hard--to--open (without an "Arkansas Toothpick," that is) plastic bubbles that enclase consumer electronics, DIY tools and who knows what else
Yoghurt cups, Mickey D's styrofoam packaging, styrofoam coffee cups, packaging "peanuts" and inserts of all kinds used to wind--up in the landfill, because the local politically connected, "honchos," who are paid huge bucks to watch "holes in the ground," didn't want to recycle it. The reason is simple: The mass to volume rato was too small! For the same reason, it also occupies a large part of open landfills.
The bridge you reference was created from "plastic wood" made from recycled yoghurt and Mickey D's "Big Mac" containers: I do not recollect the exact number... However, the cost of the building materials was considerably less than if more traditional materials had been used. Also, if I remember correctly, the building process (construction) was eased somewhat, because of the materials that were used.
Polystyrene and polycarbonate are two of the FDA--approved, "food grade" plastics. As such, they should not impact the ecosystem in a negative manner. However, if left in the sun (and weather) long enough, plastic will gradually fail and disintegrate. The mean time to failure can be prolonged by the addition of any number of chemicals/fillers/colorants/pigments that protect against UV in several ways. Similarly, the plasticity of some types of plastics can be increased by adding plasticisers. Some of these chemicals may not be "environmentallty friendly."
It would, indeed, be interesting to know the exact composition of the materials that went into the construction of that bridge --- and how they may have been modified to attain a longer life than more traditional building materials.
"Plastic wood" is being used more and more in marine construction --- in making bulkheads, for example. Also, several shore towns with boardwalks have trial--tested "plastic wood" as an alternative to more traditional woods (that splinter, and are the source of innumerable lawsuits each year), and slow--growing, exotic hardwoods from tropical forests. To date, the usage of such materials, which are, admittedly, still quite expensive, seems to be limited to the odd, donated "park bench" here and there. The public, in general, does not seem to be "enthralled."
While I, myself, probably wouldn't choose this material for construction in closed living quarters, I certainly feel that the utilization of materials made from unrenewable resources that were once thought of as "trash" are being "recycled" in a manner that seems to benefit both the economy and the environment.
ebsi