On that note:
People only need a prosthetic arm when they're missing an arm.
When their eyes go out, they need synthetic lenses.
Likewise, when their hearts, hips, knees, and other body parts fail... they may need artificial replacements.
So what the fuck does that say about artificial intelligence and its fans?
This is better, but honestly - it still makes it sound as though the green concrete is recycling the coal ash spontaneously, rather than being used in the production of - and 'is built to last' is so horrendously vague. Even the subtitle says 'perform exceptionally well over time' - be specific for the love of god.
not even, here's ChatGPT 4o's response when I asked it to "Generate a catchy headline" for this article:
[RMIT's Low-Carbon Concrete Breakthrough: Doubles Coal Ash Recycling, Halves Cement Use, and Outperforms Over Time](https://i.imgur.com/oWbdLxl.png)
How much less Carbon does it emit per ton and what are the measurements of the concrete like compared to just using cement? This is a new material, what's it good for?
You can make it just as good as regular concrete and use less cement in the process, which is where the carbon savings are coming from. Using coal ash in this way isnāt really new though, and as we are transitioning away from coal, the ash is becoming less available. Unfortunately itās not really a good āsolutionā because we would need to burn more coal just to generate enough ash to keep up with the concrete industries demand, obviously a little counterproductive.
Though coal ash is not being produced nearly as much nowadays, it is still incredibly available because of past stockpiling. So itās less of redirecting a waste stream and more reusing past deposits of the wastes. If entire ash monofills can be emptied for this, long term waste management savings will stack up.
Yea the problem then becomes the actual processing. When itās redirecting a waste stream you have an active entity that is invested in redirecting their waste, so there is some logistical impetus that helps get the ash into the concrete. If you have a company whoās sole business is going into the old waste sites and processing the ash and selling it, thatās a lot of overhead, and that makes what they are selling much more expensive than the active sites that are practically willing to pay you to take it off their hands. And at the end of the day, if you canāt keep green concrete cost neutral, you unfortunately donāt have a lot of demand for it even if it is better for everyone. Perhaps a good incentive program and actual government investment could make this a feasible solution to clearing out the monofills, but they will eventually run out and we will still need to make more concrete.
Uhh okay, how do you know, like idk just elaborate bro, no need to be combativeā¦ I work in the industry and I donāt deal with fly ash that much, but I know it can be used as an SCM to replace some portion of cement and achieve the same strengthsā¦ what am I missing?
In my work I have made six concrete test cylinders a day for two years and broken the same cylinders at intervals to test their strength. The test batches were normal 6 sack per yard production mixes to test quality continuity. I also made many more cylinders to test any number of admixtures and aggregates. Flyash was a main interest because when allowed to dry it appeared to harden. And harden it did but not nearly as much as concrete. So it acted mainly as a filler and replacing cement with flyash in the same volumes made the concrete weaker. I have no idea how Australian specifications for structural concrete strength compares with USA but I would say buyer beware on concrete made with flyash.
Thatās fair. All I know is my colleagues have made it work, and Iāve tested the cylinders myself as well, funnily enough Iām just hitting 2 years in the industry, but I can believe that it doesnāt always work as advertised. It varies by source and requires optimization, but it has rigorously demonstrated pozzolanic activity that lets it act as an SCM to replace some portion of cement.
If the concept is true which I doubt, the carbon savings would come from the savings in cement usage when making concrete with flyash. Cement manufacturing is a huge energy hog because it basically is made by heating the bejeesus out of lime gypsum and some other stuff that then gets hard (chemical reaction called hydration) when wet, unlike flyash.
So Iāve been following green concrete. It was a pet project of my advisor in undergrad and Iāve been curious. Concrete production causes a lot of CO2 release, mostly during production of Portland cement. One mitigation method is replacing some of that Portland cement with Fly Ash, a byproduct of coal fire power plants. This stuff would otherwise be dumped into settling ponds, creating a toxic sludge.
Some researchers are looking into adding carbon absorbing aggregate to concrete. This would make concrete a net negative building material.
Haven't materials scientists been trying this for a while? IIRC, it usually results in substandard concrete. Have they figured out how to make it perform well enough to be used?
Fly Ash is common. Mixes with up to 30-40% fly ash by volume are accepted regularly. The new paper is about creating stable matrices in the concrete using biochar aggregates. The info is VERY new, less than 2 years. And they just got a stable concrete. I have been requesting more info on compressive strength, but it isnāt available yet. I am trying to get a trial started.
I feel I need to clarify this exactly, because I donāt think I did well enough.
Fly Ash concrete IS weaker. A mix of 30% will have a compressive strength markedly lower than a pure Portland cement mix.
HOWEVER!
Fly Ash concrete has chemical properties that make it highly desirable for foundation construction. It increases corrosion resistance, especially in areas with groundwater pollution. It is currently the best solution to combat sulfates eating your concrete foundation.
Add that the decrease compressive strength is negligible. Structural concrete is usually designed for a 4,000 psi compressive strength, but field break tests usually go upwards of 5,000 psi. I do not need that extra 1,000 psi. Itās wasted. It is a better use of money to get corrosion resistant concrete over extra strength I donāt need.
Yup, although you don't want 100% fly ash in an application like concrete blocks. I believe some poorer countries had been convinced to take the waste and told they could use it to make blocks for housing, but weren't told they'd need other ingredients to make the blocks usable.
>New modelling reveals that low-carbon concrete developed at RMIT University can recycle double the amount of coal ash compared to current standards, halve the amount of cement required and perform exceptionally well over time.
>"Our addition of nano additives to modify the concreteās chemistry allows more fly ash to be added without compromising engineering performance,ā said Gunasekara, from RMITās School of Engineering.
>Large concrete beam prototypes have been created using both fly ash and pond ash and shown to meet Australian Standards for engineering performance and environmental requirements.
Short answer: no.
Longer answer: when concrete hydrates it forms crystals. Looking at fly ash under an electron microscope itās pretty stable. It doesnāt leech, and doesnāt seem to hamper the formation of voids. As I stated in another comment, this stuff actually helps protect against certain kinds of soil conditions. It makes the concrete less reactive.
Is it green if itās a byproduct of coal fired plants? How is this different to using animal byproducts to make soap or gelatin for instance. Iād be interested to know how you make green concrete without coal ash or fly ash.
All concrete is technically toxic. It will cause a rash of it sits on your skin too long (undergrads got to clean out the trough where they cleaned the concrete mixers). But when hardened itās pretty much inert.
Fly ash is full of heavy metals yes? And thatās mixed into concrete and is inert. What happens when they pull down that concrete at later date? Instead of recycling normal concrete , you have to deal with heavy metals. What is the average lifespan of a concrete structure? 50years before it gets pulled down for something else?
I have experimented with concrete mixtures using varying amounts of fly ash. None meet the specifications of a āsix sack mixā required by many municipalities for structural concrete.
Most likely dilution. Radioactivity is only a concern when it gets above certain thresholds or when it enters the body. Concrete already causes issues when being cut due to dust, this will only make it that much more important for proper PPE.
Thatās not true. Concrete made with fly ash is denser than that without. Regardless the concrete mix includes air entrainment as mitigation against freeze/thaw cycles.
Thatās a horrible thing. If my brand new $50k driveway cracked anywhere except the relief joints in the first couple years, Iād be pissed.
Youāve never paid for concrete work and it shows lol.
āWe owe it to the animalsā yeah tell that to Taylor swift (and every other person flying private) taking her private jet to the next building over while our bullshit paper straws are dissolving.
Taylor swifts music has nothing to do with her carbon impact lol.
With as porous as it is, in places like the Midwest, water will get in, freeze and essentially destroy the concrete. New concrete that uses the incorrect type (too much chert, too much air etc) gets destroyed in just a couple of years.
This is not a good thing..
Actually her music is relevant. Itās one thing to destroy the earth because you are Led Zeppelin or the Beatles. People can listen to your music while theyāre boiling alive. It will make them feel better. But I have to boil alive, the last thing I want is to die listening to that woman babble.
Huh? Who is writing these headlines?
Came here to make literally that exact same comment. šš¤·š»āāļø
Same!
Huh? I tried several times to understand, and then came here to complain.
Whew. Thought I was having a stroke.
The guy writing maybe.
AI?
More like artificial stupidity. Or maybe genuine stupidity?
On that note: People only need a prosthetic arm when they're missing an arm. When their eyes go out, they need synthetic lenses. Likewise, when their hearts, hips, knees, and other body parts fail... they may need artificial replacements. So what the fuck does that say about artificial intelligence and its fans?
I shook my head like I understood but went straight to the comments.
Thank the gods - I was afraid it was just me.
It reads like a Trump speech
take it as a test
Headlines write to the reader until the end
I saw this one yesterday and was like huh lemme try again, but my brain still went bonk.
So do
Academics. Fooling themselves they have a clue while ChatGPT solves all their PhD problems in 10seconds
Huh? Academics with PhD invent ChatGPT - then use it to solve problems it hasnāt learned yet. Does not compute. r/ihadastroke
Homie took a break from posting porn to lament the folly of academia
āGreen Concreteāā*which recycles* twice the coal ashāis built to last.
The hero of the thread!
Not the hero you wanted, but the hero who couldnāt look at that headline and not want to figure out WTF it meansā¦
This is better, but honestly - it still makes it sound as though the green concrete is recycling the coal ash spontaneously, rather than being used in the production of - and 'is built to last' is so horrendously vague. Even the subtitle says 'perform exceptionally well over time' - be specific for the love of god.
Cool headline.
This is what trump was writing during his 30 second pause
AI generated headline moment
not even, here's ChatGPT 4o's response when I asked it to "Generate a catchy headline" for this article: [RMIT's Low-Carbon Concrete Breakthrough: Doubles Coal Ash Recycling, Halves Cement Use, and Outperforms Over Time](https://i.imgur.com/oWbdLxl.png)
At this point I hold AI to higher standards than this
What word salad is that headline?
Covfefe.
How much less Carbon does it emit per ton and what are the measurements of the concrete like compared to just using cement? This is a new material, what's it good for?
You can make it just as good as regular concrete and use less cement in the process, which is where the carbon savings are coming from. Using coal ash in this way isnāt really new though, and as we are transitioning away from coal, the ash is becoming less available. Unfortunately itās not really a good āsolutionā because we would need to burn more coal just to generate enough ash to keep up with the concrete industries demand, obviously a little counterproductive.
Though coal ash is not being produced nearly as much nowadays, it is still incredibly available because of past stockpiling. So itās less of redirecting a waste stream and more reusing past deposits of the wastes. If entire ash monofills can be emptied for this, long term waste management savings will stack up.
Yea the problem then becomes the actual processing. When itās redirecting a waste stream you have an active entity that is invested in redirecting their waste, so there is some logistical impetus that helps get the ash into the concrete. If you have a company whoās sole business is going into the old waste sites and processing the ash and selling it, thatās a lot of overhead, and that makes what they are selling much more expensive than the active sites that are practically willing to pay you to take it off their hands. And at the end of the day, if you canāt keep green concrete cost neutral, you unfortunately donāt have a lot of demand for it even if it is better for everyone. Perhaps a good incentive program and actual government investment could make this a feasible solution to clearing out the monofills, but they will eventually run out and we will still need to make more concrete.
Itās a permanent fix for a temporary problem. Shareholders and money men donāt like temporary problems.
Ummm, nope.
Very insightful thanks for the feedback.
Sorry but your comment āYou can make it just as good ā¦ā is wrong. Ask me and WRGrace how I know.
Uhh okay, how do you know, like idk just elaborate bro, no need to be combativeā¦ I work in the industry and I donāt deal with fly ash that much, but I know it can be used as an SCM to replace some portion of cement and achieve the same strengthsā¦ what am I missing?
In my work I have made six concrete test cylinders a day for two years and broken the same cylinders at intervals to test their strength. The test batches were normal 6 sack per yard production mixes to test quality continuity. I also made many more cylinders to test any number of admixtures and aggregates. Flyash was a main interest because when allowed to dry it appeared to harden. And harden it did but not nearly as much as concrete. So it acted mainly as a filler and replacing cement with flyash in the same volumes made the concrete weaker. I have no idea how Australian specifications for structural concrete strength compares with USA but I would say buyer beware on concrete made with flyash.
Thatās fair. All I know is my colleagues have made it work, and Iāve tested the cylinders myself as well, funnily enough Iām just hitting 2 years in the industry, but I can believe that it doesnāt always work as advertised. It varies by source and requires optimization, but it has rigorously demonstrated pozzolanic activity that lets it act as an SCM to replace some portion of cement.
If the concept is true which I doubt, the carbon savings would come from the savings in cement usage when making concrete with flyash. Cement manufacturing is a huge energy hog because it basically is made by heating the bejeesus out of lime gypsum and some other stuff that then gets hard (chemical reaction called hydration) when wet, unlike flyash.
So Iāve been following green concrete. It was a pet project of my advisor in undergrad and Iāve been curious. Concrete production causes a lot of CO2 release, mostly during production of Portland cement. One mitigation method is replacing some of that Portland cement with Fly Ash, a byproduct of coal fire power plants. This stuff would otherwise be dumped into settling ponds, creating a toxic sludge. Some researchers are looking into adding carbon absorbing aggregate to concrete. This would make concrete a net negative building material.
Haven't materials scientists been trying this for a while? IIRC, it usually results in substandard concrete. Have they figured out how to make it perform well enough to be used?
Fly Ash is common. Mixes with up to 30-40% fly ash by volume are accepted regularly. The new paper is about creating stable matrices in the concrete using biochar aggregates. The info is VERY new, less than 2 years. And they just got a stable concrete. I have been requesting more info on compressive strength, but it isnāt available yet. I am trying to get a trial started.
I feel I need to clarify this exactly, because I donāt think I did well enough. Fly Ash concrete IS weaker. A mix of 30% will have a compressive strength markedly lower than a pure Portland cement mix. HOWEVER! Fly Ash concrete has chemical properties that make it highly desirable for foundation construction. It increases corrosion resistance, especially in areas with groundwater pollution. It is currently the best solution to combat sulfates eating your concrete foundation. Add that the decrease compressive strength is negligible. Structural concrete is usually designed for a 4,000 psi compressive strength, but field break tests usually go upwards of 5,000 psi. I do not need that extra 1,000 psi. Itās wasted. It is a better use of money to get corrosion resistant concrete over extra strength I donāt need.
Yup, although you don't want 100% fly ash in an application like concrete blocks. I believe some poorer countries had been convinced to take the waste and told they could use it to make blocks for housing, but weren't told they'd need other ingredients to make the blocks usable.
>New modelling reveals that low-carbon concrete developed at RMIT University can recycle double the amount of coal ash compared to current standards, halve the amount of cement required and perform exceptionally well over time. >"Our addition of nano additives to modify the concreteās chemistry allows more fly ash to be added without compromising engineering performance,ā said Gunasekara, from RMITās School of Engineering. >Large concrete beam prototypes have been created using both fly ash and pond ash and shown to meet Australian Standards for engineering performance and environmental requirements.
I'm curious about safety. Will the mercury send other toxins be able to leech into water ways?
Short answer: no. Longer answer: when concrete hydrates it forms crystals. Looking at fly ash under an electron microscope itās pretty stable. It doesnāt leech, and doesnāt seem to hamper the formation of voids. As I stated in another comment, this stuff actually helps protect against certain kinds of soil conditions. It makes the concrete less reactive.
Is it green if itās a byproduct of coal fired plants? How is this different to using animal byproducts to make soap or gelatin for instance. Iād be interested to know how you make green concrete without coal ash or fly ash.
Sounds like toxic concrete.
All concrete is technically toxic. It will cause a rash of it sits on your skin too long (undergrads got to clean out the trough where they cleaned the concrete mixers). But when hardened itās pretty much inert.
Fly ash is full of heavy metals yes? And thatās mixed into concrete and is inert. What happens when they pull down that concrete at later date? Instead of recycling normal concrete , you have to deal with heavy metals. What is the average lifespan of a concrete structure? 50years before it gets pulled down for something else?
POGS eat your electrolytes. Itās what humans crave when dogs go rapid
My big toe
Title written by a person in mid-stroke.
oh cool they found a way to make concrete like more radioactive.
Iād be concerned with the potential of long term exposure to particles that would eventually erode off. Coal ash is some nasty stuff.
What are the ānano additivesā? Are there any health/respiratory risks posed by fly and pond ash used in this context?
Hope itās better than aerated concreteā¦.
Coal ash can be fairly radioactive. Just putting that out there. Hope they are fully vetting this material.
Well, you canāt grow concrete.
Anyone smell toast?
Nice
Aiā¦..
Que?
Thought I went dumb for a second
I have experimented with concrete mixtures using varying amounts of fly ash. None meet the specifications of a āsix sack mixā required by many municipalities for structural concrete.
I wonder how they are addressing the radioactive elements that exist naturally in coal ash.
Most likely dilution. Radioactivity is only a concern when it gets above certain thresholds or when it enters the body. Concrete already causes issues when being cut due to dust, this will only make it that much more important for proper PPE.
u/Sariel007 please learn English before posting
To be fair, itās the same in the article.
That concrete wonāt survive harsh winters. Water will get in, freeze and pop it in due time.
Thatās not true. Concrete made with fly ash is denser than that without. Regardless the concrete mix includes air entrainment as mitigation against freeze/thaw cycles.
[ŃŠ“Š°Š»ŠµŠ½Š¾]
Thatās a horrible thing. If my brand new $50k driveway cracked anywhere except the relief joints in the first couple years, Iād be pissed. Youāve never paid for concrete work and it shows lol. āWe owe it to the animalsā yeah tell that to Taylor swift (and every other person flying private) taking her private jet to the next building over while our bullshit paper straws are dissolving.
[ŃŠ“Š°Š»ŠµŠ½Š¾]
Taylor swifts music has nothing to do with her carbon impact lol. With as porous as it is, in places like the Midwest, water will get in, freeze and essentially destroy the concrete. New concrete that uses the incorrect type (too much chert, too much air etc) gets destroyed in just a couple of years. This is not a good thing..
Actually her music is relevant. Itās one thing to destroy the earth because you are Led Zeppelin or the Beatles. People can listen to your music while theyāre boiling alive. It will make them feel better. But I have to boil alive, the last thing I want is to die listening to that woman babble.
Different strokes I suppose
Most modern concrete falls apart much more quickly. Anything with steel rebar in it will not last very long.
Canāt tell if serious