
A surprising number of Roman aqueducts, houses, and public buildings built with Roman concrete are still in daily use after two millennia. Apparently some of the zeolite (aluminosilicate) mortars ancient Jericho was built with 7,000 years ago are still intact. Yet our “modern” concrete buildings fall down in as little as 40 years, our highly engineered bridges in 60 or 100. We’re doing something wrong.
That “something” is Portland cement. “OPC” was invented in England in 1824 by one Joseph Aspdin, and named for the—apparently ugly gray—Portland limestone quarried nearby, which it resembles. Its advantage is that it’s easy to use: the same recipe yields the same concrete wherever in the world you use it. Its disadvantages are that it is a horribly conductive, radiative heat sink; it is not waterproof; it grows mold and mildew; it spalls apart, or even explodes, in a fire; and it freezes and thaws and expands and contracts with temperature and humidity, so it inevitably cracks, letting water reach the steel with which we reinforce it. The steel rusts, expands, and breaks the concrete.
OPC sets when molecules of various calcium carbonates “hydrate,” surround themselves with water molecules. Somehow that turns mud into stone, but stone that is always full of water, and that water can move through. It is strongest when mixed with the least water needed to fully hydrate it, but then it is much too stiff to pour, and packing it in by hand costs more than capitalism wants to spend on labor. The excess water has to evaporate out; it never does in a thick pour, and can take a couple of years in one perhaps 8 inches thick. As OPC dries it shrinks, and cracks. It can freeze and thaw, and crack. It expands and contracts with changes in temperature and humidity, and cracks. It has almost no tensile strength, bending strength/flexibility, or shear strength; look at it cross-eyed, and it cracks. Even microcracks let water vapor reach the rebar, which rusts, expands three times, and breaks the concrete apart. It gets “concrete cancer” and begins to crumble.
OPC and steel poison each other.
The construction, OPC, and steel industries all love this: it is welfare and future business. Not so good when buildings fall on people, or bridges fall out from under drivers. We taxpayers have to pay to rebuild it all, and our grandkids will have to pay to rebuild it all again. Planned obsolescence with a little negligent homicide thrown in.
Manufacturing OPC requires huge quantities of dirty energy, and produces lots of nasty air pollution besides greenhouse gasses (GHGs), including nitrous oxides and sulfur dioxide (acid rain). We make about 4.6 billion tons of cement--not concrete, just cement, the binder--every year, and a ton of cement averages .86 ton of CO2. That's almost 4 gigatons of CO2 from that one industry. So manufacturing OPC already produces around 8 percent of anthropogenic GHGs, and if we rebuild, and China and India and the rest of the developing world “modernize” with OPC, its use will increase at least fourfold by 2050—China already uses 40 times as much as we do—and we can kiss a habitable climate and a couple million innocent species and perhaps our own goodbye.
There are better cements.
I talk about several alternative cements, useful for various purposes, in Pumping the Brakes on Climate Change, but those we’re going to want to rebuild/build new infrastructure with are geopolymer cements. “GPCs” use reactive aluminosilicates—coal fly ash, steel mill slag, metakaolin clay, ground glass, volcanic ash, crushed basalt, granite, serpentine. olivine, slate—activated with something alkaline that makes them gel, polymerize, and set. Sodium hydroxide (caustic soda, lye) is often used; sometimes calcium hydroxide, or sodium silicate, common “water glass.”
You use just enough water to activate the alkali, and the concrete expels the water from the middle out as it sets, so that it is dry inside. It doesn’t crack remotely as readily as OPC, sets and gains strength faster, is alkaline, which protects rebar from rust, and is compatible with cellulosic reinforcement--bonds with it and protects it from fire and rot--like bamboo and hemp: OPC can be persuaded, but it doesn’t like the sugars and acids that come with cellulose.
GPCs are far more fire resistant than OPC—a fire can flash the water in OPC to steam and blow it apart--and are used as fireproofing. Fly ash and slag are toxic wastes: making cement with them sequesters those toxins (mostly metals). They’re called geopolymers because they polymerize like plastics, form covalent bonds each molecule with the next, and with most any aggregate or reinforcing, in all directions. That’s several times stronger, and far more flexible, than OPC. And GPCs should last far, far longer: you’re essentially making inert glass, not chemically-vulnerable limestone. Broken glass buried 4,000 years ago can still be sharp. Glass is forever. More or less.
Making GPCs produces 80 or 90 percent less GHGs than OPC. And some formulations draw lots of CO2 right out of the atmosphere, and bond with it, as they set; emphasizing those could help greatly to sequester atmospheric carbon. One carbon-sequestering GPC that's rather beautiful is called Ferrock. Once in production GPCs should cost less than OPC. They need far less energy to manufacture, can made from virtually any aluminosilicate rock, and the production plant is smaller and less expensive, so they’ll save us taxpayers money. GPCs might last centuries or even millennia—a gift to the grandkids, instead of ever more debt—and are an essential part of fixing the climate, and so leaving the kiddos a future.
I hope I don't have to read the whole Infrastructure Investment and Jobs Act, (HR 3684, Public Law 117-58, November 15, 2021), to learn if congress wrote the infrastructure bill with a care to the climate instead of pork for the Portland cement industry. The largest on the planet, they must have lots of lobbyists. Congress could have specified geopolymer or other non-OPC cements for future government-funded infrastructure and construction projects. Government could lend--not grant!—industry the money to build GPC manufacturing plants. There are some already up and running; lend those money to expand, if they wish. Even at the prime rate, the taxpayers would get something back to lend to the next clean start-up industry.
Depending upon your locally-available raw materials, you’ll need a different mix, and a different ratio of possibly a different activator, to make good GPC concrete, but once you have your local materials figured out it should be as simple as following a recipe, with due care for the caustic nature (before mixing) of alkaline activators; lots of industrial materials require a little care in handling.
We will need more cement chemists/engineers. It might be good to start training them now.
I can’t know until I get my hands on some, and it is not available yet. But if Blue Crete, formerly Blue World Crete, is everything developer Dr. Daniel Robert says it is, it has all of the properties of other geopolymer cements, has up to seven times the tensile strength of OPC, is amazingly flexible, does not crack, forms covalent bonds with almost anything, is hydrophobic and non-porous and needs no finish, resists algae/mold/mildew/barnacles/ bacteria/zebra mussels and corrosion, is utterly fireproof and refractory—doesn’t melt—to 2700 °F, —and, Panitz says, insulates to around R-17.5/inch depending upon what you use for aggregate. Three or four inches would be a passive house. Super-strong, millennia-durable, utterly fireproof concrete that superinsulates will hugely simplify construction.
If Panitz has what he says he has, I see a less-expensive way to make unreinforced masonry buildings earthquake resistant, and insulate, waterproof, and air seal them at the same time, with BC and perhaps bamboo. I see a solution to the affordable housing and homelessness crises in salvaging, reinforcing and remodeling such buildings into low-cost apartments.
The concrete walls of new commercial buildings are furred in with steel studs, and insulated, sheet rocked, taped, textured, caulked, and painted inside and out. You’d need none of those materials or labor: pour the tilt-up panel, stand it up and join it to the next panel, the floor and the roof membrane, caulk between and you're done. I see a way to build houses with BC, the shell of which might cost half as much, or less, than wood frame construction. Those homes would be super-insulated and utterly fireproof--your refuge instead of your pyre in a wildfire--and might last a thousand years. They would be extremely energy efficient, inexpensive to keep very comfortable, and need little maintenance.
BC should cost at least 20 percent less than OPC: for one thing, a portable = mass producible plant to make it should, Robert says, cost only 5 to 10 percent as much as a $200 million OPC plant. You don't have to burn energy calcining--cooking--anything, so Blue Crete’s carbon footprint is at least 90 percent less than OPC’s, and would be negative with cellulosic aggregates and reinforcing: “Blue Wood” is strong and tough, fireproof, takes and holds nails and screws, and cuts with woodworking tools.
I'd really like to design a few passive houses (homes so well insulated and sealed that they keep themselves warm/cool with very little energy) around Blue Crete, maybe show Tornado Alley how to build affordable homes that are tornado shelters instead of death traps, with the stuff. That would need a paradigm shift; you gotta live in a Hobbit house. But if it would protect you and yours and everything you worked for all your life from the worst mother nature could throw at you, and you knew it would shelter many generations to come, if it needed little or no maintenance, if it kept you comfortable on very little energy/money, if its carbon footprint were a fraction that of a (firetrap, disposable) stick-built house, and particularly if it cost less, you might decide that Hobbit houses are cute and that living in Hobbiton or Underhill next door to the Bagginses could be way cool. Literally, and without air conditioning, which is already 5 percent of climate change and also growing exponentially.
I gather from talking to him a few times that Dr. Robert could use some help, getting Blue Crete to market. If BC is everything he says it is, it will be tragic if its use doesn't spread across the world, right now. Hopefully someone reading this, or the relevant parts of Pumping the Brakes on Climate Change, will see the potential of Blue Crete, and offer Panitz the help he needs. My idea, not his.
-----------
Rebuilding with Portland cement would condemn our grandkids to paying to rebuild it all again, in another 60 or 100 years or so; likely they will still be in debt for this rebuild. But they will be too busy trying to survive a climate gone haywire, and the floods fires heat drought famine and war that will bring, to bother with crumbling bridges, and without its bridges a nation falls apart. Geopolymer cements will save us money, last far longer, and leave the future a future. And if Blue Crete does everything Dr. Robert says it does, we can use it to solve the affordable housing crisis. I'd love to show you how.
And now would be good.
---------------------------------------
Endnotes from Ch. 11) Clean Building Materials: Concrete, Steel and Aluminum. P. 249 , PTBOCC. These are only the references to do with OPC and GPC.
---------------------------------------
358 “Alternative Cement,” Project Drawdown, accessed June 10, 2020,
https://www.drawdown.org/solutions/materials/alternative-cement
359 Stephanie Pappas, “Watch Concrete Explode As Scientists Probe Weird Phenomenon.” Live
Science, May 06, 2019, https://www.livescience.com/65398-concrete-explodes-in-weird-
video.html
“Watch Concrete Explode From High Heat.” CONCRETE CONSTRUCTION, May 6, 2019,
https://www.concreteconstruction.net/business/technology/watch-concrete-explode-from-high-
heat_c same video, different take.
360 John Gajda and Joe Nasvik ,“Why Thermal Cracking Happens & How to Control It,” For
Construction Pros.com, June 21, 2017.
https://www.forconstructionpros.com/concrete/article/20862452/why-thermal-cracking-happens-
how-to-control-thermal-
cracking#:~:text=Concrete%20temperatures%20which%20exceed%20air,35%C2%BAF%20can
%20cause%20thermal%20cracking
361 Dean McCartney, “The problem with reinforced concrete,” The Conversation, June 17, 2016,
https://theconversation.com/the-problem-with-reinforced-concrete-56078
362 Runit Dome on Enewetak Atoll. US Defense Special Weapons Agency, accessed Jan 26,
2022: http://sonicbomb.com/albums/album61/runit.jpg via
https://commons.wikimedia.org/wiki/File:Runit_Dome_001.jpg
363 Joseph Davidovits, “Properties of Geopolymer Cements.” Geopolymer Institute, Saint-
Quentin, France, 1994, https://www.geopolymer.org/wp-content/uploads/KIEV.pdf
364 Kelsey Simpkins, “Cities of the future may be built with algae-grown limestone.” CU Boulder
Today, University of Colorado Boulder, June 23, 2022,
https://www.colorado.edu/today/2022/06/23/cities-future-may-be-built-algae-grown-limestone
365 John Mathews, Professor of Strategic Management, Macquarie Graduate School of
Management, “Eco-cement, the cheapest carbon sequestration on the planet,” The Conversation,
Dec. 17, 2012 https://theconversation.com/eco-cement-the-cheapest-carbon-sequestration-on-
the-planet-10978
366 Geopolymer Solutions, “Cure Time and Strength Design,” Geopolymertech website, accessed
March 21, 2021, https://www.geopolymertech.com/ . This website is a treasure trove of info on
geopolymer cements. (Conroe, Texas)
367 TechEco home web page https://www.tececo.com.au/
368 Eric Oh, “This New Brick by MIT-Researchers Uses Little Energy and Helps Deplete
Landfills.” Arch Daily, July 15, 2015, https://www.archdaily.com/770277/this-new-brick-by-mit-
researchers-uses-almost-no-energy-and-depletes-landfills
369 “UA Invention-Turned-Startup Offers Revolutionary Eco-friendly Substitute for Cement,”
Tech Launch Arizona, The University of Arizona, Nov. 4, 2014,
https://techlaunch.arizona.edu/news/ua-invention-turned-startup-offers-revolutionary-eco-
friendly-substitute-cement
370 PBS New Hour, “This cement alternative absorbs CO2 like a sponge,” YouTube, Apr. 13,
2015, 7:25. Excellent journalism. https://www.youtube.com/watch?v=yWPzERdNh50
371 Blue World Sciences website: http://science4solutions.net/ Lots of good information here.
372 Press Release, “Green Cement Company Emerges as Leader in New Sciences for Agriculture
and Energy Industries,” Newswire, Mar. 13, 2014; BWC joint venture with Navrattan Free
Power. https://www.newswire.com/green-cement-company-emerges-as/265795
Heads up: Navrattan stole Blue World Crete’s intellectual property. That’s part of the larger
story, too.
373 Lia Miller, “Smog-Eating Cement,” The New York Times Magazine, Dec. 9, 2007
https://www.nytimes.com/2007/12/09/magazine/09smogeatingcement.html
374 Kate Ryan, “This Pollution-Absorbing Cement Could Clean Up Smoggy Cities,” Good, Dec.
21, 2017. https://www.good.is/articles/pollution-absorbing-cement
That “something” is Portland cement. “OPC” was invented in England in 1824 by one Joseph Aspdin, and named for the—apparently ugly gray—Portland limestone quarried nearby, which it resembles. Its advantage is that it’s easy to use: the same recipe yields the same concrete wherever in the world you use it. Its disadvantages are that it is a horribly conductive, radiative heat sink; it is not waterproof; it grows mold and mildew; it spalls apart, or even explodes, in a fire; and it freezes and thaws and expands and contracts with temperature and humidity, so it inevitably cracks, letting water reach the steel with which we reinforce it. The steel rusts, expands, and breaks the concrete.
OPC sets when molecules of various calcium carbonates “hydrate,” surround themselves with water molecules. Somehow that turns mud into stone, but stone that is always full of water, and that water can move through. It is strongest when mixed with the least water needed to fully hydrate it, but then it is much too stiff to pour, and packing it in by hand costs more than capitalism wants to spend on labor. The excess water has to evaporate out; it never does in a thick pour, and can take a couple of years in one perhaps 8 inches thick. As OPC dries it shrinks, and cracks. It can freeze and thaw, and crack. It expands and contracts with changes in temperature and humidity, and cracks. It has almost no tensile strength, bending strength/flexibility, or shear strength; look at it cross-eyed, and it cracks. Even microcracks let water vapor reach the rebar, which rusts, expands three times, and breaks the concrete apart. It gets “concrete cancer” and begins to crumble.
OPC and steel poison each other.
The construction, OPC, and steel industries all love this: it is welfare and future business. Not so good when buildings fall on people, or bridges fall out from under drivers. We taxpayers have to pay to rebuild it all, and our grandkids will have to pay to rebuild it all again. Planned obsolescence with a little negligent homicide thrown in.
Manufacturing OPC requires huge quantities of dirty energy, and produces lots of nasty air pollution besides greenhouse gasses (GHGs), including nitrous oxides and sulfur dioxide (acid rain). We make about 4.6 billion tons of cement--not concrete, just cement, the binder--every year, and a ton of cement averages .86 ton of CO2. That's almost 4 gigatons of CO2 from that one industry. So manufacturing OPC already produces around 8 percent of anthropogenic GHGs, and if we rebuild, and China and India and the rest of the developing world “modernize” with OPC, its use will increase at least fourfold by 2050—China already uses 40 times as much as we do—and we can kiss a habitable climate and a couple million innocent species and perhaps our own goodbye.
There are better cements.
I talk about several alternative cements, useful for various purposes, in Pumping the Brakes on Climate Change, but those we’re going to want to rebuild/build new infrastructure with are geopolymer cements. “GPCs” use reactive aluminosilicates—coal fly ash, steel mill slag, metakaolin clay, ground glass, volcanic ash, crushed basalt, granite, serpentine. olivine, slate—activated with something alkaline that makes them gel, polymerize, and set. Sodium hydroxide (caustic soda, lye) is often used; sometimes calcium hydroxide, or sodium silicate, common “water glass.”
You use just enough water to activate the alkali, and the concrete expels the water from the middle out as it sets, so that it is dry inside. It doesn’t crack remotely as readily as OPC, sets and gains strength faster, is alkaline, which protects rebar from rust, and is compatible with cellulosic reinforcement--bonds with it and protects it from fire and rot--like bamboo and hemp: OPC can be persuaded, but it doesn’t like the sugars and acids that come with cellulose.
GPCs are far more fire resistant than OPC—a fire can flash the water in OPC to steam and blow it apart--and are used as fireproofing. Fly ash and slag are toxic wastes: making cement with them sequesters those toxins (mostly metals). They’re called geopolymers because they polymerize like plastics, form covalent bonds each molecule with the next, and with most any aggregate or reinforcing, in all directions. That’s several times stronger, and far more flexible, than OPC. And GPCs should last far, far longer: you’re essentially making inert glass, not chemically-vulnerable limestone. Broken glass buried 4,000 years ago can still be sharp. Glass is forever. More or less.
Making GPCs produces 80 or 90 percent less GHGs than OPC. And some formulations draw lots of CO2 right out of the atmosphere, and bond with it, as they set; emphasizing those could help greatly to sequester atmospheric carbon. One carbon-sequestering GPC that's rather beautiful is called Ferrock. Once in production GPCs should cost less than OPC. They need far less energy to manufacture, can made from virtually any aluminosilicate rock, and the production plant is smaller and less expensive, so they’ll save us taxpayers money. GPCs might last centuries or even millennia—a gift to the grandkids, instead of ever more debt—and are an essential part of fixing the climate, and so leaving the kiddos a future.
I hope I don't have to read the whole Infrastructure Investment and Jobs Act, (HR 3684, Public Law 117-58, November 15, 2021), to learn if congress wrote the infrastructure bill with a care to the climate instead of pork for the Portland cement industry. The largest on the planet, they must have lots of lobbyists. Congress could have specified geopolymer or other non-OPC cements for future government-funded infrastructure and construction projects. Government could lend--not grant!—industry the money to build GPC manufacturing plants. There are some already up and running; lend those money to expand, if they wish. Even at the prime rate, the taxpayers would get something back to lend to the next clean start-up industry.
Depending upon your locally-available raw materials, you’ll need a different mix, and a different ratio of possibly a different activator, to make good GPC concrete, but once you have your local materials figured out it should be as simple as following a recipe, with due care for the caustic nature (before mixing) of alkaline activators; lots of industrial materials require a little care in handling.
We will need more cement chemists/engineers. It might be good to start training them now.
I can’t know until I get my hands on some, and it is not available yet. But if Blue Crete, formerly Blue World Crete, is everything developer Dr. Daniel Robert says it is, it has all of the properties of other geopolymer cements, has up to seven times the tensile strength of OPC, is amazingly flexible, does not crack, forms covalent bonds with almost anything, is hydrophobic and non-porous and needs no finish, resists algae/mold/mildew/barnacles/ bacteria/zebra mussels and corrosion, is utterly fireproof and refractory—doesn’t melt—to 2700 °F, —and, Panitz says, insulates to around R-17.5/inch depending upon what you use for aggregate. Three or four inches would be a passive house. Super-strong, millennia-durable, utterly fireproof concrete that superinsulates will hugely simplify construction.
If Panitz has what he says he has, I see a less-expensive way to make unreinforced masonry buildings earthquake resistant, and insulate, waterproof, and air seal them at the same time, with BC and perhaps bamboo. I see a solution to the affordable housing and homelessness crises in salvaging, reinforcing and remodeling such buildings into low-cost apartments.
The concrete walls of new commercial buildings are furred in with steel studs, and insulated, sheet rocked, taped, textured, caulked, and painted inside and out. You’d need none of those materials or labor: pour the tilt-up panel, stand it up and join it to the next panel, the floor and the roof membrane, caulk between and you're done. I see a way to build houses with BC, the shell of which might cost half as much, or less, than wood frame construction. Those homes would be super-insulated and utterly fireproof--your refuge instead of your pyre in a wildfire--and might last a thousand years. They would be extremely energy efficient, inexpensive to keep very comfortable, and need little maintenance.
BC should cost at least 20 percent less than OPC: for one thing, a portable = mass producible plant to make it should, Robert says, cost only 5 to 10 percent as much as a $200 million OPC plant. You don't have to burn energy calcining--cooking--anything, so Blue Crete’s carbon footprint is at least 90 percent less than OPC’s, and would be negative with cellulosic aggregates and reinforcing: “Blue Wood” is strong and tough, fireproof, takes and holds nails and screws, and cuts with woodworking tools.
I'd really like to design a few passive houses (homes so well insulated and sealed that they keep themselves warm/cool with very little energy) around Blue Crete, maybe show Tornado Alley how to build affordable homes that are tornado shelters instead of death traps, with the stuff. That would need a paradigm shift; you gotta live in a Hobbit house. But if it would protect you and yours and everything you worked for all your life from the worst mother nature could throw at you, and you knew it would shelter many generations to come, if it needed little or no maintenance, if it kept you comfortable on very little energy/money, if its carbon footprint were a fraction that of a (firetrap, disposable) stick-built house, and particularly if it cost less, you might decide that Hobbit houses are cute and that living in Hobbiton or Underhill next door to the Bagginses could be way cool. Literally, and without air conditioning, which is already 5 percent of climate change and also growing exponentially.
I gather from talking to him a few times that Dr. Robert could use some help, getting Blue Crete to market. If BC is everything he says it is, it will be tragic if its use doesn't spread across the world, right now. Hopefully someone reading this, or the relevant parts of Pumping the Brakes on Climate Change, will see the potential of Blue Crete, and offer Panitz the help he needs. My idea, not his.
-----------
Rebuilding with Portland cement would condemn our grandkids to paying to rebuild it all again, in another 60 or 100 years or so; likely they will still be in debt for this rebuild. But they will be too busy trying to survive a climate gone haywire, and the floods fires heat drought famine and war that will bring, to bother with crumbling bridges, and without its bridges a nation falls apart. Geopolymer cements will save us money, last far longer, and leave the future a future. And if Blue Crete does everything Dr. Robert says it does, we can use it to solve the affordable housing crisis. I'd love to show you how.
And now would be good.
---------------------------------------
Endnotes from Ch. 11) Clean Building Materials: Concrete, Steel and Aluminum. P. 249 , PTBOCC. These are only the references to do with OPC and GPC.
---------------------------------------
358 “Alternative Cement,” Project Drawdown, accessed June 10, 2020,
https://www.drawdown.org/solutions/materials/alternative-cement
359 Stephanie Pappas, “Watch Concrete Explode As Scientists Probe Weird Phenomenon.” Live
Science, May 06, 2019, https://www.livescience.com/65398-concrete-explodes-in-weird-
video.html
“Watch Concrete Explode From High Heat.” CONCRETE CONSTRUCTION, May 6, 2019,
https://www.concreteconstruction.net/business/technology/watch-concrete-explode-from-high-
heat_c same video, different take.
360 John Gajda and Joe Nasvik ,“Why Thermal Cracking Happens & How to Control It,” For
Construction Pros.com, June 21, 2017.
https://www.forconstructionpros.com/concrete/article/20862452/why-thermal-cracking-happens-
how-to-control-thermal-
cracking#:~:text=Concrete%20temperatures%20which%20exceed%20air,35%C2%BAF%20can
%20cause%20thermal%20cracking
361 Dean McCartney, “The problem with reinforced concrete,” The Conversation, June 17, 2016,
https://theconversation.com/the-problem-with-reinforced-concrete-56078
362 Runit Dome on Enewetak Atoll. US Defense Special Weapons Agency, accessed Jan 26,
2022: http://sonicbomb.com/albums/album61/runit.jpg via
https://commons.wikimedia.org/wiki/File:Runit_Dome_001.jpg
363 Joseph Davidovits, “Properties of Geopolymer Cements.” Geopolymer Institute, Saint-
Quentin, France, 1994, https://www.geopolymer.org/wp-content/uploads/KIEV.pdf
364 Kelsey Simpkins, “Cities of the future may be built with algae-grown limestone.” CU Boulder
Today, University of Colorado Boulder, June 23, 2022,
https://www.colorado.edu/today/2022/06/23/cities-future-may-be-built-algae-grown-limestone
365 John Mathews, Professor of Strategic Management, Macquarie Graduate School of
Management, “Eco-cement, the cheapest carbon sequestration on the planet,” The Conversation,
Dec. 17, 2012 https://theconversation.com/eco-cement-the-cheapest-carbon-sequestration-on-
the-planet-10978
366 Geopolymer Solutions, “Cure Time and Strength Design,” Geopolymertech website, accessed
March 21, 2021, https://www.geopolymertech.com/ . This website is a treasure trove of info on
geopolymer cements. (Conroe, Texas)
367 TechEco home web page https://www.tececo.com.au/
368 Eric Oh, “This New Brick by MIT-Researchers Uses Little Energy and Helps Deplete
Landfills.” Arch Daily, July 15, 2015, https://www.archdaily.com/770277/this-new-brick-by-mit-
researchers-uses-almost-no-energy-and-depletes-landfills
369 “UA Invention-Turned-Startup Offers Revolutionary Eco-friendly Substitute for Cement,”
Tech Launch Arizona, The University of Arizona, Nov. 4, 2014,
https://techlaunch.arizona.edu/news/ua-invention-turned-startup-offers-revolutionary-eco-
friendly-substitute-cement
370 PBS New Hour, “This cement alternative absorbs CO2 like a sponge,” YouTube, Apr. 13,
2015, 7:25. Excellent journalism. https://www.youtube.com/watch?v=yWPzERdNh50
371 Blue World Sciences website: http://science4solutions.net/ Lots of good information here.
372 Press Release, “Green Cement Company Emerges as Leader in New Sciences for Agriculture
and Energy Industries,” Newswire, Mar. 13, 2014; BWC joint venture with Navrattan Free
Power. https://www.newswire.com/green-cement-company-emerges-as/265795
Heads up: Navrattan stole Blue World Crete’s intellectual property. That’s part of the larger
story, too.
373 Lia Miller, “Smog-Eating Cement,” The New York Times Magazine, Dec. 9, 2007
https://www.nytimes.com/2007/12/09/magazine/09smogeatingcement.html
374 Kate Ryan, “This Pollution-Absorbing Cement Could Clean Up Smoggy Cities,” Good, Dec.
21, 2017. https://www.good.is/articles/pollution-absorbing-cement
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