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Author | Topic: ACI versus EPA: What happens when you put non-scientists in charge of science issues | |||||||||||||||||||||||||||||||||||||||
Taz Member (Idle past 3321 days) Posts: 5069 From: Zerus Joined: |
crashfrog writes:
You'd be surprised to know how many people don't know it's a chemical reaction. They think it "dries" much the same way that bread dries and becomes hard bread.
It cures, that is, there's a chemical reaction where, um, calcium carbonate forms a hydrated crystal? Sorry, that's the best I can do from memory (and guessing.) All my chemistry knowledge is organic at this point. I have a question, I guess; my understanding is that the toxicity of fly ash is a function of the heavy metals present in coal that don't combust. I completely accept your claim that the fly ash particles become embedded and fused with the cement matrix. But concrete is permeable to water in many cases. What's the possibility of heavy metals in the fly ash component of concrete moving into a mobile water phase?
No need for complicated answers. Fly ash has been quietly used in concrete mixes since the 20s, and probably long before that. Nothing has happened. Again, there's a reason why the ACI and other engineers and scientists in the field have been working in a semi-quiet mode about flyash. We're fully aware that it's very harmful to people. That's why we want to lock it into concrete so that there's no chance of it seeping out to the environment. And we're also fully aware that to the general public it sounds scary. There's no escaping the fact that most of our energy comes from the burning of coal. We can either find something useful for flyash or we can dump all of it into land fills. In this particular case, labeling is extremely essential to whether we'll continue to recycle and use flyash or dump everything into landfills.
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Taz Member (Idle past 3321 days) Posts: 5069 From: Zerus Joined: |
Well, in that case I apologize for my previous response.
Once flyash is mixed into concrete, it is chemically locked into the concrete matrix. It's part of the concrete. Again, I must point out that fly ash has been used in concrete mixes since the 20's. No ill effect yet.
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Coragyps Member (Idle past 764 days) Posts: 5553 From: Snyder, Texas, USA Joined: |
But concrete is permeable to water in many cases. What's the possibility of heavy metals in the fly ash component of concrete moving into a mobile water phase? FWIW, one of the main things fly ash does to concrete/cement is to make it less permeable to water. And you're only talking about a millidarcy or so permeability to start with in normal construction cement anyway. Yes, heavy metals could leach out, but not near as quickly as they would from loose flyash in a landfill.
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crashfrog Member (Idle past 1496 days) Posts: 19762 From: Silver Spring, MD Joined:
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They think it "dries" much the same way that bread dries and becomes hard bread. I wouldn't be surprised that this is the common view, I guess, because hardly anybody knows anything about anything. But, people with expertise in fields are sensitive to the common misapprehensions about what they do. My wife is an entomologist (now for the Army!) and it drives her up the wall when people refer to spiders as insects.
We're fully aware that it's very harmful to people. That's why we want to lock it into concrete so that there's no chance of it seeping out to the environment. And we're also fully aware that to the general public it sounds scary. My guess would be that knowledge about what fly ash is, and why it is produced, is about as common as the knowledge that concrete cures instead of dries - that is, not very. I had only ever heard of fly ash because of that disaster in Tennessee I linked to. (A billion fucking gallons of fly ash slurry, right into the goddamn river! Unbelievable. If fly ash in concrete prevents shit like that, I'm all for it.)
In this particular case, labeling is extremely essential to whether we'll continue to recycle and use flyash or dump everything into landfills. You're not giving us much to go on but your word (and the word of a few other engineers) that the (accurate) labeling of fly ash as "hazardous waste" is an impediment to its widespread use in concrete. As you point out, it's been going into concrete for several decades. Is there a specific example of a case where engineers planned to use fly ash concrete, but were stopped because of mistaken concerns about its safety? That's the part I guess I'm skeptical about.
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Coragyps Member (Idle past 764 days) Posts: 5553 From: Snyder, Texas, USA Joined: |
Fly ash has been quietly used in concrete mixes since the 20s, and probably long before that. Natural pozzolan from volcanos is very similar to flyash (except that it probably has a different set of toxics in it) and was used by the Romans to make all those aqueducts two millenia ago.
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Taz Member (Idle past 3321 days) Posts: 5069 From: Zerus Joined: |
crashfrog writes:
There's a reason why the ACI and other concrete engineer organizations are stressed out over this issue. We're all aware of how gullible people are when it comes to soundbites to the regular folks. As you point out, it's been going into concrete for several decades. Is there a specific example of a case where engineers planned to use fly ash concrete, but were stopped because of mistaken concerns about its safety? Again, there's a reason why concrete engineers have been somewhat quietly using flyash in concrete mixes. We know how scary it sounds to the general public. But I guess you're right. Now that the cat is out of the bag, we'll just have to wait and see if the fallout is as bad as the ACI is thinks it will be. Personally, I'm with the ACI here. People are stupid morons. I honestly believe this. That's why the majority still don't believe in evolution. And that's why most of them still don't believe in climate change even though the issue has been settled years ago in the scientific community. In fact, people get elected by saying they don't believe in evolution or they don't believe in climate change. Think a couple years from now. THIS JUST IN, CONSPIRACY AMONG CONCRETE ENGINEERS TO HIDE TOXIC HAZARDOUS WASTE RIGHT UNDERNEATH YOUR FEET! THIS JUST IN, MOST PEOPLE ARE SWIMMING IN TOXIC HAZARDOUS WASTE WITHOUT KNOWING IT! CONSERVATIVE MORAL CHRISTIAN OBLIGATION TO RID SOCIETY OF TOXIC HAZARDOUS WASTE. You know how much tea partiers and conservatives love sensationalist language. Just wait and see.
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Dr Adequate Member (Idle past 314 days) Posts: 16113 Joined: |
THIS JUST IN, CONSPIRACY AMONG CONCRETE ENGINEERS TO HIDE TOXIC HAZARDOUS WASTE RIGHT UNDERNEATH YOUR FEET! THIS JUST IN, MOST PEOPLE ARE SWIMMING IN TOXIC HAZARDOUS WASTE WITHOUT KNOWING IT! CONSERVATIVE MORAL CHRISTIAN OBLIGATION TO RID SOCIETY OF TOXIC HAZARDOUS WASTE. You know how much tea partiers and conservatives love sensationalist language. Just wait and see. Well, that depends on how you spin it. If you tell them that sequestering fly-ash in concrete will protect the environment and is a form of ecologically responsible recycling, they'll be against it. If you tell them that it will increase profits for big corporations while exposing ordinary Americans to carcinogens, they'll ask if there's any way they can help.
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crashfrog Member (Idle past 1496 days) Posts: 19762 From: Silver Spring, MD Joined: |
Think a couple years from now. Ok, but think a couple of years from now in the alternate universe where the EPA stops classifying fly ash as hazardous waste:
quote: I feel like there's a middle ground where fly ash can be used in concrete but free fly ash has to be stored in such a way as to recognize is as a threat to aquifers due to toxic levels of heavy metals which can leach into water. And I feel like that middle ground is where the EPA gives an exception to concrete manufacturers and builders to use fly ash in concrete, but classifies bulk fly ash as a "hazardous waste", since it's a waste product that is hazardous.
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Wounded King Member Posts: 4149 From: Cincinnati, Ohio, USA Joined: |
Previously Fly Ash hasn't been classified as hazardous waste.
The compromise you suggest is pretty much exactly what the EPA describes as its proposed position with fly ash intended for reuse if it become more tightly federally regulated. Fly Ash intended for a 'beneficial use' would be exempted from classification as hazardous waste. TTFN, WK
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Taz Member (Idle past 3321 days) Posts: 5069 From: Zerus Joined: |
I think I understand why you guys can't see how critical this issue is. You guys aren't working in this field and so you have trouble understanding what the big problem is.
Let's take a step closer to home for you guys. Remember the cobb county board of education sticker on every biology text book in their schools?
quote: After reading that statement several times, I still think every part of that disclaimer is true. But it's deceiving. It's telling the truth while painting a false picture. Labeling ash fly as hazardous toxic waste, while accurate, paints a wrong picture for the public. It incites irrational knee jerk reaction from joe and jane schmoes.
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Omnivorous Member Posts: 3991 From: Adirondackia Joined: Member Rating: 6.9 |
Taz writes: I think I understand why you guys can't see how critical this issue is. You guys aren't working in this field and so you have trouble understanding what the big problem is. The EPA was previously allowing fly ash to be used as fill for road embankments. The GOP just voted to let fly ash be treated as routine municipal trash. You think others are too far away from the issue. I think you are too close.
Labeling ash fly as hazardous toxic waste, while accurate, paints a wrong picture for the public. It incites irrational knee jerk reaction from joe and jane schmoes. I don't think we should lie, whether by omission or commission, in the name of a greater or more pragmatic truth. Ever. Edited by Omnivorous, : +,"If you can keep your head while those around you are losing theirs, you can collect a lot of heads."
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Taz Member (Idle past 3321 days) Posts: 5069 From: Zerus Joined: |
Then you approve of the disclaimer sticker in Kansas?
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Omnivorous Member Posts: 3991 From: Adirondackia Joined: Member Rating: 6.9 |
So you think the EPA categorization of fly ash as hazardous waste is an attempt to undermine the legitimacy of science?
"If you can keep your head while those around you are losing theirs, you can collect a lot of heads."
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Taz Member (Idle past 3321 days) Posts: 5069 From: Zerus Joined: |
Omni writes:
I asked the question first. So you think the EPA categorization of fly ash as hazardous waste is an attempt to undermine the legitimacy of science? Do you approve of the disclaimer sticker?
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Omnivorous Member Posts: 3991 From: Adirondackia Joined: Member Rating: 6.9
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Fine.
No, I don't approve of the sticker, because it singles out a specific set of scientific findings as requiring a caution label urging critical regard because of the sticker proponents' ideological interests. The content is accurate, but in the context of singling out evolution for the disclaimer, it is false. You, similarly, though inversely, are singling out a hazardous waste for not-labeling because of your own professional interests. It is you, not I, who is endorsing the disclaimer sticker by emulating it. Your example--the label--while true, is applied with the intent to subvert the truth through its prejudicial application, as though evolution required special scrutiny. The truthful labeling of fly ash, on the other hand, does not represent an inversion of the normal and accurate labeling of other hazardous waste. Now you answer my question."If you can keep your head while those around you are losing theirs, you can collect a lot of heads."
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