Posted September 25, 200816 yr County touts new plastic bridge http://www.norwalkreflector.com/articles/2008/09/25/front/iq_623614.txt By MARY LISA BOOSE - Reflector Staff Writer | Thursday September 25 2008, 11:25am ----------------------------------------------------------------------------- Interesting article, to say the least. The Huron County Engineer is one of the more progressive, forward-thinking elected individuals in the area... ----------------------------------------------------------------------------- Huron County Engineer Joe Kovach will officially open a new era for bridge construction in the state at 10 a.m. Friday at a ribbon cutting for a Fairfield Township bridge made of plastic. There are no steel reinforcing rods, no prestressed concrete box beams; instead, fiber reinforced polymers (FRPs) make up the 17-foot long, 24-foot wide span on Ridge Road south of Ohio 162. The FRPs are made up of polyester resins, vinyl ester resins and glass fibers.
September 25, 200816 yr Polymer engineers represent! :-D (I'm in the polymer dept at Case for those of you who don't know)
September 29, 200816 yr Good luck recycling those materials. Plus, it probably leeches harmful chemicals (BPA, perhaps?) into the water or elsewhere. I don't like the idea at all. Not one bit. It would have been perfect for the 20th century, when we weren't so concerned with the environmental and health impacts. Some people might not be concerned even now (or are completely oblivious), but we should be.
September 29, 200816 yr Kovach and his staff have spent almost two years in planning, researching and developing this "bridge for the next century." Bridge for the next century? Polymers and resins are oil-based. As this century progresses, we're going to have less and less of the stuff...
September 29, 200816 yr It would be interesting to see a life-cycle analysis comparing the experimental bridge-decking material with conventional steel and concrete. The production of both steel and concrete requires a lot of energy input and produces a lot of emissions.
September 30, 200816 yr Okay, allow me to have a second of nerddom :-D. Polyester and vinyl ester resins don't rely as heavily upon oil as other polymers like polyethylene do. Also, they don't contain BPA. That's primarily found in BPA-based polycarbonate. And it's really not that big of an issue - chemistry gets such a bad rap from people who don't know anything about it but what the news media says. Badmouthing it based on media is like me saying that this country will collapse if the bailout plan doesn't pass (when in reality, I know not much at all about banking and the stock market). Okay, rant over.
September 30, 200816 yr Kovach and his staff have spent almost two years in planning, researching and developing this "bridge for the next century." Bridge for the next century? Polymers and resins are oil-based. As this century progresses, we're going to have less and less of the stuff... That too.
September 30, 200816 yr Okay, allow me to have a second of nerddom :-D. Polyester and vinyl ester resins don't rely as heavily upon oil as other polymers like polyethylene do. Also, they don't contain BPA. That's primarily found in BPA-based polycarbonate. And it's really not that big of an issue - chemistry gets such a bad rap from people who don't know anything about it but what the news media says. Badmouthing it based on media is like me saying that this country will collapse if the bailout plan doesn't pass (when in reality, I know not much at all about banking and the stock market). Okay, rant over. I wasn't claiming that it *does* contain BPA. That's why I said *perhaps*. My main concern is how such construction will NEVER break down and NEVER be recycled.
September 30, 200816 yr Okay, allow me to have a second of nerddom :-D. Polyester and vinyl ester resins don't rely as heavily upon oil as other polymers like polyethylene do. Also, they don't contain BPA. That's primarily found in BPA-based polycarbonate. And it's really not that big of an issue - chemistry gets such a bad rap from people who don't know anything about it but what the news media says. Badmouthing it based on media is like me saying that this country will collapse if the bailout plan doesn't pass (when in reality, I know not much at all about banking and the stock market). Okay, rant over. I wasn't claiming that it *does* contain BPA. That's why I said *perhaps*. My main concern is how such construction will NEVER break down and NEVER be recycled. Esters are one of the easiest polymers to decompose. That's why a lot of biodegradable biomaterials are made from polyesters - the ester linkage is readily hydrolyzed in the body. However, given that this is a thermoset resin, it will probably degrade more slowly - never, however, is a rather strong suggestion that is most likely incorrect. How much steel and concrete from typical bridges is usually recycled? I'm just curious.
September 30, 200816 yr Esters are one of the easiest polymers to decompose. That's why a lot of biodegradable biomaterials are made from polyesters - the ester linkage is readily hydrolyzed in the body. However, given that this is a thermoset resin, it will probably degrade more slowly - never, however, is a rather strong suggestion that is most likely incorrect. How much steel and concrete from typical bridges is usually recycled? I'm just curious. Steel at construction and demolition sites: 95% Rebar: 50% Steel: 68% (2001) | 57% (2000) Newspaper: 80% Cardboard: 70%
September 30, 200816 yr Esters are one of the easiest polymers to decompose. That's why a lot of biodegradable biomaterials are made from polyesters - the ester linkage is readily hydrolyzed in the body. However, given that this is a thermoset resin, it will probably degrade more slowly - never, however, is a rather strong suggestion that is most likely incorrect. How much steel and concrete from typical bridges is usually recycled? I'm just curious. Actually, 99%. Pretty good! We shall see - this is a rather new technology after all, so I'm sure if it gathers enough use that someone will find a way to re-use these materials. All part of the scientific evolution process :).
September 30, 200816 yr Okay, allow me to have a second of nerddom :-D. Polyester and vinyl ester resins don't rely as heavily upon oil as other polymers like polyethylene do. Also, they don't contain BPA. That's primarily found in BPA-based polycarbonate. And it's really not that big of an issue - chemistry gets such a bad rap from people who don't know anything about it but what the news media says. Badmouthing it based on media is like me saying that this country will collapse if the bailout plan doesn't pass (when in reality, I know not much at all about banking and the stock market). Okay, rant over. I wasn't claiming that it *does* contain BPA. That's why I said *perhaps*. My main concern is how such construction will NEVER break down and NEVER be recycled. Esters are one of the easiest polymers to decompose. That's why a lot of biodegradable biomaterials are made from polyesters - the ester linkage is readily hydrolyzed in the body. However, given that this is a thermoset resin, it will probably degrade more slowly - never, however, is a rather strong suggestion that is most likely incorrect. How much steel and concrete from typical bridges is usually recycled? I'm just curious. Through a web search, from a high school chemistry book: "Thermosetting plastics differ from thermoplastics because once they have been formed, they cannot be remelted or remoulded. Examples include bakelite, vulcanised rubber, melanine (used to make furniture), and many glues. Thermosetting plastics are generally stronger than thermoplastics and are better suited to being used in situations where there are high temperatures. They are not able to be recycled. Thermosetting plastics have strong covalent bonds between chains and this makes them very strong." There should also be concern as to the pollution created when these materials are refined. Discussing and determining point source pollution would be never ending though. All I am saying is that this plastic bridge makes it nearly impossible to reuse for other purposes. Plus, the breakdown of plastics (not to be confused with decomposition) emits toxins into the air and into the water.
September 30, 200816 yr I know that thermosets cannot be melted or dissolved, hence the term thermoset. Additionally, you can engineer molecules such that the decomposition products may not be as harmful to the environment. If this technology catches on and gathers widespread use (and that's a big if), at some point, adaptave re-use and environmentally-safe decomposition products will be addressed by someone. Just because the material can't be melted or dissolved, doesn't mean it won't find use. One application I can immediately think of is for packing materials. Grind it up into pellets! There are a lot of creative minds out there.
September 30, 200816 yr I know that thermosets cannot be melted or dissolved, hence the term thermoset. Additionally, you can engineer molecules such that the decomposition products may not be as harmful to the environment. If this technology catches on and gathers widespread use (and that's a big if), at some point, adaptave re-use and environmentally-safe decomposition products will be addressed by someone. Just because the material can't be melted or dissolved, doesn't mean it won't find use. One application I can immediately think of is for packing materials. Grind it up into pellets! There are a lot of creative minds out there. Sorry to keep beating a dead horse (that quote was more for my reference), but if you grind it up into pellets, they're still going to impact the environment. We already use styrofoam and other plastics as for packing materials, which are also harmful. There's already a problem with the breakdown of weaker plastics in the products we buy. They're currently floating around in the ocean as pellets, posing a threat to many ecosystems. It sure has the same effect on land ecosystems as well. I agree with you on the "creative minds" thing though. I'm all for the production of plant-based plastics, but alas, they're very expensive. Hopefully we can make some headway on that front. I don't know enough about them to know their capabilities for more durable applications though. Let's get back to the hurrah for the plastic bridge. I'm sure some people are happy about it.
September 30, 200816 yr County touts new plastic bridge http://www.norwalkreflector.com/articles/2008/09/25/front/iq_623614.txt By MARY LISA BOOSE - Reflector Staff Writer | Thursday September 25 2008, 11:25am He said the main advantage of the new bridge is it will not corrode, a key consideration in a state where roads and bridges take a beating every winter from ice, snow and road salt. I've heard that the lifespan of the deck is 75 years, and could be as long as 100 years. The deck's wearing surface is asphalt and can be surfaced along with the rest of the road every 10-20 years. Compare to normal concrete decked bridges, which would have to be re-decked twice during that 100 year time frame, and most likely jackhammered and repaired (concrete overlaid in addition to the asphalt overlay), more often than that, maybe every 20 years. That much less concrete and steel has to be produced to repair the traditional bridge, and as Rod pointed out, is environmentally damaging. Not to mention the transportation of the heavier concrete and steel to the site vs. the lighter bridge. I'm sure you heard that a vast majority of bridges need replacement and there is no money. the vast majority of bridges are small ones like this; now imagine the vast majority of these small bridges of this 'build it and forget' type. Imagine all that money we do not need to invest in these small bridges on their upkeep.
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