It doesn't matter that there's not enough waste to replace all of the concrete use in the world. We just need to replace enough to make an environmental difference. If we use up all of the waste products available to make this stuff, we will not only drastically reduce concrete, we will have cleaned up all of those other messes! What's not to love?
What is the benefit of using hazardous materials for building living compartments? I don`t get that. The same goes for these plastic tiles which are produced in India. They are horrible for the environment, animals and for humans. We already have big issues with microplastics in the air, water and soil. Using a mixed plastic (because the melt different kinds of plastics together) for walking or street plaster, makes it even worse. The abraision will pollute the envirnoment much more than just burning the plastic using filteration for energy production. I don`t get the ignorance on human pollution and why we always make things worse, when we try to fix things we produced in the first palce
@@michaspringphul The idea, I think, is to sequester the waste. It's there already, so better it be sealed into a form that it can't escape. As for plastic tiles, they probably should only be used for low-abrasion surfaces, not floors. I can think of many possibilities there. You have a valid point on how we always make things worse. I think it's because of the conquest mentality. We mess up by conquering something, and then we try to solve it by conquering the problem, and that makes still more problems. We have to learn how to think cooperatively, find a use for everything the way nature does, fit everything into its ideal place and not try to impose what works in one situation on some different situation (like using plastic tiles for flooring.) The waste isn't going to vanish--we have to figure out what to do with it.
I work at a steel plant. The slag is heavy. So much so that we smoked a cement truck trying to use it to make some of this stuff. We had a hose spraying the radiator to try to keep it cool. Not an insurmountable problem just need more powerful better cooled equipment.
Or you have to make and transport less of it at a time which means it is going to be more expensive. Unless people need specific properties they don't want to pay more.
Great presentation. I have worked on Fly ash based geopolymers and found interesting results. Every advantage you discussed is observed in the geopolymer. Now I am working on waste glass geopolymer, where we don't need Sodium silicate and also a low concentration of NaOH is required. Once standards and rules are established, I think geopolymers will be the future of building materials
Would you consider doing a video on cost/benefits of historical preservation versus tear-down/new building construction? At what point is a building too far gone, or it’s purpose too inefficient to preserve? What are other ways of preserving buildings while also accommodating contemporary community needs? I remember a sky scraper on Sansome Street in San Francisco that preserved pieces of the street-level facade, while replacing the entire original building with a new skyscraper. Love your videos!
I would suspect that there are too many factors to come to a generalized conclusion comparing the two. How degraded is the plumbing system; how outdated is the electrical configuration; what type of foundation does the building have and what condition is that in; how efficient is the insulation of the building; is the building still structurally sound; what zoning regulations have changed since the building was first constructed; what is the intended use of a replacement building. The list goes on, and any one of those variables on its own could make or break a decision to retrofit vs rebuild.
@@DryBonz1 - there are also differences in "feel". Somethings about an older structures with their old growth wood, lime plaster, milk paint and Tung oil as opposed to laminates, partical board, synthetic stone, polyurethane and latex paint.
San Antonio tried to rebuild/replace 70 year-old dilapidated, crime-infested, low-rent neighborhoods. Police departments in nice neighborhoods fought the projects because they didn't want the displaced crime and drugs pushed into their areas.
There are almost no more available Fly ash or slag (GBFS) in the European market, as it is already in use in cement and concrete. In many ways we already have a semi-geopolymer concrete in the market. For instance, in the Norwegian market the standard cement has 20 % fly ash, and another has 70 % slag. Yes, Geopolymerconcrete will be more common, at least in some more specific applications, but it is still much more important to reduce environmental footprint from the ordinary portland cement production.
The fly ash isn't relevant. It is the polymer bond. Geopolymer is typically a OH hydroxide bond. Portland cement is a calcium bond. Two very different materials.
Greatly explained :), And also the scanty supply of source materials for Geopolymer concrete synthesis you talked about is a major Impediment to its large scale applications... Thats exactly what we addressed in our research here at National University of Sciences and Technology, Pakistan, We replaced fly ash with newer source materials i.e. agricultural waste ashes (they are also rich in alumina and silica and thus conducive to Geopolymer synthesis) We found that strength remained intact for upto 15-20% replacement level
Any thoughts on replacing steel rebar with lighter basalt rebar? With the reduction in weight, walls can be thinner, further reducing the amount of cement in a structure. Also, basalt would never rust.
I am going to start my masters thesis on geopolymer concrete. If they have made this material and has also been applied in the world, what do we need to research about?
@@maheendaud7615 well there's plenty of things yet to discover, like you can use some newer source materials instead of fly ash for example rock based geopolymers are very interesting Also you can explore synthesis of chemical activators from waste materials for example sodium silicate can be derived from biomass waste and used as an activator, So if you read the latest papers you will find the current research trends and a ressearch gap for your thesis as well
Looks like these waste products come from processes which also need to be heavily reduced or eliminated. 1. Burning coal is maniacally bad. 2. The process to get metakaolin are very energy intensive itself. 3. Slag has the same problem, though steel production seems unavoidable. One barrier is that it has many other useful applications. 4. The environmental problems of palm oil production are well documented. I also hope that we learned from biofuels that competing with food is not such a great idea.
As someone who had permanent eye damage from sodium hydroxide burns, yeah, the liquid component of geopolymers is nasty stuff. That the activator is a corrosive liquid that requires separate packaging is a logistical hassle, too. Caveats aside it's a useful engineering material that can be applied in certain niches. As a spray-on foam fire barrier it's hard to beat, and combined with construction methods like monolithic domes and non-metallic tensile reinforcement like basalt rebar, can make long-life low maintenance structures. A monolithic-geopolymer-basalt dome could probably last longer than the Pantheon.
I suspect a more significant barrier to replacing Portland cement than manufacturers is that architects and engineers want to work with proven materials.
Hey Belinda, Your videos are really informative. Yes Geopolymers are really versatile material. I am an architect doing research in the subject. I've been to the Geopolymer Institute in France to attend GP camp in 2018 and had interacted with Prof. Daviodovits. The potential in India is immense as we still have coal power plants, but I think suitable thermally activated Aluminous and Silicious materials can be found anywhere in the world. Some of my friends who attended the camp in 2018 are experimenting with bottom ash of incerinators. Portland cement has been, over the centuries, standardized. GPC is still very new in that respect. But I am sure that standardization will happen. I recently came across a paper from Arizona University which explored the total replacement of virgin aggregates in GPC. The developments happening all over the world in this field is really exciting. I think you should do a video on other uses of GP like LTGS for making stabilized soil blocks and high strength ceramics using GP - both lesser explored possibilities, especially the ceramics.
There is no question that humanity will have to manage their resources better if we expect to remain on this planet. What a nice summary and introduction in the pros and cons of geopolymer's. Last year I discovered Polymeric paver sand and just loved what you can do with it. By framing my paver patter, adding colored stone, brushing the sand between the gaps, sweeping off the surface and adding water, can create some artistic designs, such as walkways, that are not only lovely to look at but are waterproof and will last for years. Thank you Ms. Carr for your presentation and insights in this emerging technology. Nice job!
The long term durability of roman concrete apparently involves the use of volcanic ash which reacts with salt water creating a harder material. The fact that this sort of chemistry isn't used to reinforce the concrete that we use is kind of silly. Granted volcanic ash is hard to come by unless you're near a former volcano, the fact that simple and basic chemistry isn't used more often is interesting. Simply because we'll do stuff like taking steel rebar and dipping it in plastic in attempt to prevent galvanic corrosion, but ultimately end up exacerbating the issue even further by focusing all the corrosion in specific points.
Epoxy rebar is a non starter. That stuff is dreadful by trapping moisture against the steel. Phosphate solutions are gaining a lot of traction for bridges and highways.
Definitely sounds like it would be best used in the applications it most excels in, to the extent that the relevant waste streams can support, rather than as a general purpose concrete. Perhaps some of the businesses already in the industries that manage those waste streams could be given tax incentives to make partnering with the businesses that utilize those byproducts more lucrative and cost effective than just letting it sit there. Sometimes it just takes a little grease to get the wheels spinning in a new industry, especially when it encroaches a bit on the territory of an old industry. Great topic, editing, and presentation - really like your shirt, too!
Fly Ash is usually used in northern climates instead of salt during the winter. Fly Ash was used in IL. in the 1970' & 1980's. Using Portland cement & aggregate ( sand & rock) can be poured in all the types of weather. I have poured concrete in the middle of winter in northern IL with no adverse effects. Concrete is a better way to pour highways, bridges, & over passes than asphalt.
What is worth to consider it that cement manufactureres such a CEMEX are incorporating more and more waste materials into their mixes, the concrete then still fits into standard regulations and behaves similarly. Meanwhile it still gains some of the advantages geopolymers have. The content of portland cement in cement is therefore sinking. I think in europe we have seen a supplementation of 25% in the last 15 years, at somepoint as Belinda mentioned the supply of flyash etc will be exhausted.
Great presentation. I have worked with Geopolymers and I know that material have many advantage versus Portland Cement, I think geopolymers will be the future of building materials
I firmly believe it's not the materials, it's how we've chosen to use them and our lack of adaptability or willingness to change. Your videos are fascinating and I always learn something. Thank you. :)
I wouldn't worry much about sodium hydroxide. Portland cement is plenty caustic as it is. While using SH to dissolve silica into sodium silicate happens at very high pH, the product is not. I definitely understand that as we (hopefully) move away from coal/palm oil and toward more sustainable renewables the raw materials for geopolymer will also decline. I'm not an engineer, so I never factor concrete for tensile strength. I'd be interested to know just how different geopolymer is in this regard. Fly ash is nasty stuff, but I can see it being used for applications you mentioned like sea walls and road beds. Thanks for bringing up the topic. 🙂
Any geopolymer seller would most likely already mix the SH with silica to the Best ratio that is not caustic. SiO2:Na2O ratio above 1.5 should not be caustic, from Wikipedia.
Thank you so much for the expertly crafted content! You're brilliant at conveying complex topics and I appreciate above all your commitment to earth-conscious engineering.
Hi, geopolymer fan here. I would like to add that one of the most common raw material for geopolymer is ferro-kaolin (an aluminosilicate source). They could be used to make ferro-sialate geopolymer. They basically exist everywhere. It's not the aluminosilicate that is rare, but the alkali metal that is crucial for the chemical reaction. There's only so much salt in the world and producing sodium hydroxide in the scale required to make geopolymer as common as ordinary Portland cement is just too expensive. But researches have shown calcium in ggbs form can substitute some of the sodium/potassium in the reaction, and 1 atom of calcium can replace 2 of them. So it IS possible for geopolymer to replace Portland cement. And sodium hydroxide is rarely used directly on site if you are talking about commercial products. Any geopolymer mix designer that is aware of the danger of NaOH should have design safe and ready to use solution of sodium silicate or potassium silicate
The biggest drawback is that fly ash is radioactive, you would be building structures that produced massive amounts of radon gas. My company looked at using fly ash back in 2007, we went with other geopolymer mixtures, steer clear of fly ash.
Would that still be an issue for structures like motorways or airport runways? Places that are well ventilated and where few people are walking around on them? Just trying to think of best-use scenarios. The more we can turn waste into useful products, the better.
@@WavegirlThinks I think if you do structures on that scale with a product like fly ash you have to control leaching into the ground water, air quality. I’m guessing heating it would cause it to off gas even more, places downwind of airports would have noticeably higher radon levels I’d wager, “might be EPA safe levels, I always question if their levels are applicable to newborns.” Some things really just need to be contained and not put back into the stream of use, I believe fly ash is one of those. Joseph Davidovits has many geopolymer recipes, My company’s been working with recipes based on his research for almost two decades, we incorporate aeration methods and more modern additives like silicon carbide whiskers. Geopolymers are the future, but we always have to look at everything we’re putting in.
@@nedisawegoyogya There are dozens of geopolymer recipes in Davidovits book, and many old Roman concrete recipes that do the job. I just wanted to warn folks about fly ash products, there have been companies slinging that toxic trash at people for decades now, it’s a crime that our children will pay for, radiological decay rates shouldn’t be a factor in your homes construction.
There might actually be cause for some concern with geopolymer cement, the long life span might mean the particulate formed from the natural erosion gpc might become a breathing hazard and impossible to clean up if adoption reach the level of Portland cemen. Just a conjecture on my end though
When adding waste materials to concrete mix, is there any concern about volatile chemical off gassing that would endanger inhabitants? And how much of these specific waste materials do we actually produce in the associated industries? How much concrete could we make with our existing production, as compared to avail cement?
With fly ash and slag, both are created at high enough temperatures that any volatile compounds that may have existed in the raw materials are completely burned off.
YES ! Egypt pyramids for sure , a worthy subject and an interesting one too ! ---- a big THANK YOU for all your quality work , KEEP SHINING , KEEP SMILING & KEEP SHARING THE KNOWLEDGE --- from Canada J.
This is the single most important topic on the table today, with relevancy to every human on earth. Thank you for posing such a concise explanation, of the technical aspects. So I must interject, that while Potassium (K) is usable in these equations, this is not a wise use of Potassium. Sodium based Geopolymer is just as good as Potassium laced GP, and conserves potassium for use in Agriculture. The use of Geopolymers is predicted to grow exponentially over the next decade. If we do not, there are going to be some serious short term and long term health issues for all humans. Over the last two decades, the worldwide average Oxygenation level (expressed as an overall percentage) has dipped over 1%. This is due in large part to the release of CO2 during the creation of Portland Cement. I propose a mandatory moratorium on construction projects which require Concrete. if we take a break, and then limit the total amount of Concrete which can lawfully be produced worldwide, we will have a solution. This requires a massive international effort, drastic steps, and severe economic and legal consequences for individuals and organizations whom will inevitably skirt the laws. Personally I can tell you without batting an eye that China is out. They will likely never fully modernize, until long after it is too late. But the rest of us can use this GP as an intended Gift from above. People need to begin to think in more sustainable context. The widespread new construction wave that has spread worldwide is choking the air, polluting the water, and causing material shortages in every market. Next year over 20 Million people will die prematurely due to chronic lung conditions caused and exacerbated by poor air quality, smoke, contaminants, and low Oxygenation levels. This could have been prevented if Davidowitz's theories had been properly pursued in 1979. It is a truly shameful state of affair, that corporations are permitted to shape the course of humanity. Even worse that they choose to ignore their responsibility and pursue deadly policies of using toxic garbage to manufacture the fake reality we have become trapped by. As a Construction Inspector and Energy Consultant in Southern California, I spend half my workday on construction sites. This week alone I have been out to over 40 sites. I am witnessing the use of GP in decorative and non weight bearing applications already. In fact many builders are using "GP mix kits" purchased online to make Fake Granite, Faux Marble, even Synthetic Diorite. My suggestion is that Builders mix fly ash, slag and waste ash together to make a contiguous mixture which may be easily replicated in the field. Fly ash can be added to conventional Portland cement to stretch the recipe. This was common practice until more research was done. So, it turns out Fly Ash and slag benefits the overall mixture considerably. The addition of ash to cement increases strength while also adding moisture resistance, it lowers the heat of set, increases plasticity and decreases the water need. The result is a concrete that is harder, stronger, more water tight, and requires less to create. In Southern California we use 13% Fly Ash by weight. This mixture is a level which was agreed to by many parties, regarding many factors including cost, time, and usability. However this is just a drop in the bucket. Lowering demand is the long term solution to the concrete problems. No matter what certain products will have to be made from scratch, even with GP. So we have to change our thinking about what is and is not necessary to build. If we do absolutely have to build something, maybe we can scale it down a bit. DO we really need more lanes on the freeway? How about going to work from 10 to 7 instead of 8 to 5? Little things add up...
I have done my research in MUET, Jamshoro Pakistan on geopolymer concrete by using local NaOH as alkali activator instead of using laboratory grade NaOH since it is very costly and less market supply as you discussed in this video. The results i got from this research were seem very good as compared to conventional concrete.
It is an intriguing concept, and does seem like an opportunity to mitigate the environmental impact of concrete somewhat, but the availability problem definitely limits how much we could invest in it as the future of concrete, particularly since one of the sources of waste material are coal power plants, which are just another environmental issue that we want to scale down rather than up.
You are absolutely right collin, the scanty amounts of source materials is a major issue, and recent trends of shutting down coal power plant has further exacerbated the issue... We at National University of Sciences Technology Pakistan conducted a research on newer source matrials of late, And found that agricultural waste ashes are conducive to Geopolymer concrete synthesis as well, principally due to high amount of amorphous alumina and silica
Excellent presentation! I always learn so much from watching Belinda Carr's videos. I think the Canadian company Plaex is using this type of product in their composite block system.
2:20 fly ash use is forbidden as a concrete filler in german... for the same reasons you made up for it's use. We thought asbestos was a good material, I don't want to know how bad these waists could be in our walls...
I find the subjets and the manner in which you present them to be very interesting and pleasant to watch. All the best to you and thank you. Dave & The Girls
For bridges geopolymers are bad choice where ever winters are below freezing temperatures. The geopolymers I have tested at work do dot endure freeze cycles when there are any salt present.
Thank you for sparing us from the surprisingly complex chemical details and using a quick summary instead. I’m particularly interested in the fire resistance and insulating qualities of the air containing formulations. We really need non-flammable alternatives to traditional construction materials like wood and pvc lumber. Fire danger is increasing ever year and it’s become a surburban issue, not just a wildland-urban interface problem. Blowing embers can go anywhere.
Coal ash? So the idea is to take a toxic waste product that nobody wants, sitting in special landfills around the country, loaded with radio active elements, heavy metals, and add that to my foundation or slab? Why don't we insulate with some asbestos residues for good measure, can't wait to invite the grandkids over. PS: I do like your videos.
I've also thought about the blocks on the pyramids being poured-in-place as opposed to mined from a quarry. It makes sense, considering the weight of each block.
There really are several big problems with the idea that the blocks were formed in place. 1. The quarries from which the stones came have been identified. In at least some cases there was writing documenting the pharaoh of the time. 2. There are Egyptian depictions of blocks being transported on sleds (with a man at the front pouring a liquid onto the sand). 3. Then there is the documentation from Merer. The oldest known papyrus (dating back to the time of Khufu) is a sort of diary/accounting for the activities of his crew and how they transported casing stones from a quarry to the area of the Great Pyramid. Interestingly, his notes were found far from where his casing stone activities occurred - it seems likely that he had transported his boat to a different location to support copper mining/processing. There area lots of things we don't really know about the pyramid construction (heck, there is a void in the Great Pyramid which we don't know how to access). But we do know that the stones were quarried. It is also quite clear that a good portion of the construction was not of precisely fitted stones - and there is (IMHO) good reason to believe that a whole lot of the more central volume of the Great Pyramid is debris from the quarrying. The idea of stones formed/poured in place is attractive but it is inconsistent with what has been learned over the years.
@@oldguy1030the great Pyramids are over 10 thousand years old ..the real people who built them where long dead before those depictions existed ..they discovered them not built them..to put it short there is no way those blocks can be pulled ..they where built on site
@@ProblematicT9k pyramids are not 10000 years old. this is just a fantasy that you've seen on some clickbait documentary made for gullible people. oldguy1030 is citing actual science, which rejected the cast block hypothesis decades ago. you should learn how to cite real research yourself
Excellent video. Up here in Canada, our team is working on developing a locally sourced geopolymer cement formula for use in 3D printed concrete houses!
How do you guys ensure that proper adhesion happens on stacked layers especially with no rebar. No offense as I don't know your company, but a lot of companies in the game seem like their teams have 0 experience in the construction world and are trying to solve problems that don't exist.
You know that story about British colonists putting a bounty on snakes to reduce the snake population which led to people breeding more snakes for the money? What if this gets super popular and the ingredients stop being byproducts?
One of the interesting ideas Bucky Fuller came up with was prestressed concrete for highways. Bolted together on substrate. It provided better performance and easier repair/replacement. I’m wondering how geopolymers would work in this environment?
Perhaps Govt incentivised initiatives under waste reduction/recycling could require that this material be exclusively used in Govt only projects where tax breaks can also be given to raw material producers within reasonable proximity to projects. That way, the Govt is playing the role that it should really play; doing the right thing in the interest of the future and its people.
Wagner's - developers of Wellcamp - have been in polymer cement for years. They also manufacture fibre reinforced plastic cross arms for power networks.
Production of the waste materials currently used for making Geopolymer cement is in rapid decline for good reasons. Has any work been done on finding an alternative primary source of silicates and a process that is scalable and environmentally sound?
Rice husks are high in silica. I can also see bagasse supplementing the rather more onerous palm shells for some of that high carbon ash Belinda mentioned.
Belinda should do one on hemp crete. Very sustainable and can reduce not only water consumption but has a net zero carbon emissions. I would love to here your pros and cons on the matter.
Recently there is also Ferrock a mix of Steel Slag & Crushed Glass powder what I like about ferrock is it doesn't look like gray concrete it comes out many shades of iron reds and also sometimes layers turn out to be black
Just like Belinda mentioned, it does sound good, but it's made of ingredients which all come from industrial waste, which means the suppy of it is limited by how much can you get. However you can get cement anywhere, just do a little digging, do a little burning, and a little mixing! I can't imagine my country getting Metakaolin, and we don't have coal power plants here to get the fly ash.
Well you can also synthesize geopolymers using geological resources like calcined clay and laterite, these are prepared at temperature 3 times lesser than that used for making cement
In terms of things like fly ash, there are significant inclusions of radioactive and other problematic materials such as high arsenic and mercury compounds. What's the purification process for this (e.g. do they remove the toxic materials)? As well, has anyone done a material degradation test in terms of use in roads and other high-abrasion situations where geopolymers are ground down from their original construction and leach into the environment?
Sounds like similar materials to glass- this would pair well with basalt rebar. Since basalt is essentially a glass fiber stronger than steel rebar per weight (basalt is much lighter), constructed wall and deck thicknesses could be much thinner. This in turn would mean every 3 tons of cement could be displaced by just 1 ton of geopolymer. Skyscrapers, bridges, dams, large public works, should all be the ideal target projects. How about desalination domes in the middle of the Sahara, and giant aquaducts linking Mauritania to Egypt. Such a project to green the Sahara could end poverty in northern Africa, providing a backbone for a linear city and ending world hunger with adjacent agriculture land watered with solar distilled seawater, despite global warming. Any potential for a translucent geopolymer?
Definitely would like to have a better understanding of costs (knowing that economies of scale would control or reduce cost eventually). Seems like there are enough current applications where it could continue to prove itself as a great way to use waste materials. Thanks.
Fly ash has long been added to concrete. When Jeffrey Energy Center was build unit #1 was in service when concrete was being poured for unit #3. They mixed fly ash from #1 into the concrete for #3.
Thank you! I considered make another silly thumbnail pointing to the geopolymer print, but decided against it. I really don't know what the magic formula for a thumbnail and title on YT is.
Fly ash is infamously very toxic, mostly bc of all the heavy metals. It feels strange to not comment on the safety of using it as a material in close proximity to humans even if it is encapsulated? Steel slag is also pretty shit afaik. Has there been any long term studies on this?
I like the idea of light-weight concrete for a residential roofing alternative rather than asphalt/petroleum, as asphalt roofing has a limited 15-25 year life-span before it needs replacement. I know there is metal and ceramic roofing but I like to know we have other options.
Waste salt for waterproof building materials by Israeili University is being worked on. Plus Eric Geboers and The Salt Project needs waterproof coating material that should be available made from algae or existing chemicals.
It's great to learn more about this polymer concrete. In colder regions, we are unable to make our roads from traditional concrete largely because of frost heave and water damage, so it would be wonderful if the characteristics of this type of concrete could give us options. Cost is always an issue, though...
I live in a northern cold region - we use asphalt because it is easy to repair - has decent water dispersion and can expand/contract alright without much cracking.
@@corail53 Exactly! But asphalt is also energy intensive to produce, reliant on fossil fuels, and has a short lifespan. In areas with a lot of traffic, the asphalt can last less than two years causing a permanent disruption to traffic over a small area. I also worry about leaching benzene into the water table.
A brilliant use of a waste product/s, that said we should be looking at the cause, the originators of the waste and finding alternatives that don’t produce the harmful waste products.
Magnesium Oxide is the most significant cement in history. It should be mentioned as a geopolymer. There is more than enough of it to replace Portland cement. It is non-toxic. It has fabulous properties. It probably deserves a month's worth of episodes.
What about sea-crete, made from electrically charged nets in ocean water drawing and solidifying carbonates? If it can scale, it is a huge carbon sink, itself a suggested method for carbon sequestration.
Maybe lobby large retailers like Menards and Home Depot to carry it for small scale residential use. As an engineer the concept is very interesting. Anything to reduce landfill usage. On that matter I believe we should burn our garbage to extract the energy as opposed to landfilling it.
Additional things to think about with fly ash are the minor constituents depending upon the specific coal bed composition but may include one or more of the following elements or compounds found in trace concentrations (up to hundreds ppm): gallium, arsenic, beryllium, boron, cadmium, chromium, hexavalent chromium, cobalt, lead, manganese, mercury, molybdenum, selenium, strontium, thallium, and vanadium, along with very small concentrations of dioxins and PAH compounds.[1][2] It also has unburnt carbon.[3][4]. Source Wikipedia
Definitely make a video about the theory that Egyptian pyramids were made of geopolymers. If you touch on or go deeply into other possible sites using geopolymers so much the better. Fascinating.
Thank you for vid, i used to follow Davidikus always wondered how the limestone blocks they made a few years ago in paris are doing. Could be another part of your Egyptian themed video. Take care
5:49 the calculation is the same. 0.9 / ton for a component mixed 1 to 5 parts vs 2 part mix at 0.2 that you need 5x the quantity of. before mention of the substantial difference in price. They are both good, but not the same thing. we need more plants, rather than more plant based concretes
Hey Belinda, I just stumbled across your channel and this is very informative. I would love a video on the egyptian geopolymer pyramids theory please :).
1. You may wish to explore Basaltic Fiber rebar, reinforcement bars made from fused bundled fibers drawn from melted basalt. This type of rebar does not corrode, so when water penetrates the concrete the rebar does not expand from rusting, thus eliminating or greatly diminishing one cause of failure of modern concrete. 2. Yes, a video on the theory of cast geopolymer stone in construction of some of the pyramids would be interesting. However you may wish to take note of the remains of a form of windlass and of what is called Petrie's Cradle. With these devices many of the stone blocks could have been rolled into general position. Quite possible that several types of methods were used. Interesting.
I am starting to replace the roof on my house in Portugal as have a lot of people. This leaves me with a lot of old terra cotta tiles waste. I was wondering about doing vegetable growing in an inert material rather like hydroponics. I though oh I am going to need tons of the stuff. Then the penny dropped crush up the tiles. Now it occurs to me that I could crush them up for concrete for low stress jobs. This could go on forever.
It is important for people to understand the difference between the CO2 that is produced in the cement making process, and the CO2 that is produced from oxidizing carbon (burning fuel): CO2 produced by burning fuel gets its Oxygen from the atmosphere, and that O2 will not return to the atmosphere unless it is photosynthesized by terrestrial plants. It has no net change in atmospheric density. Following photosynthesis, the carbon that was extracted from petroleum or coal becomes soil organic matter, a resource that is in desperately short supply. CO2 produced by making concrete liberates Carbon and Oxygen trapped in carbonate rock - 'fossilized air', if you will. Both the Carbon _and_ the Oxygen that were lost from our atmosphere when the rock was formed are returned to the atmosphere: This results in a net gain in atmospheric density and pressure. When _this CO2 undergoes photosynthesis, we get some of our atmosphere *back.* As is the case with carbon from oxidizing fuel, the carbon from making cement will become soil organic matter. Currently, our atmosphere is a little too light for optimal human health - about 133 *trillion* tons too light - and we are constantly losing atmosphere. Geopolymers may be better than cement in some ways, but they do not replenish our atmosphere in the way that making cement does. Breaking up monopolies, and in particular, removal of code restrictions will create more opportunities for the making of conventional cement (which helps to improve the atmosphere by releasing fossil CO2, as previously stated) as well as geopolymers, that sound wonderful for disposing of waste materials - many of those same waste materials can be cast in cement blocks, as well, for that matter.
Actually PFA and GBBS are commonly used as additives in cement and concrete products in markets where they are economically available. A reason their usage is limited to being an additive instead of a direct replacement is because as waste products, their chemical composition will fluctuate. Power Plant A burning coal from Source B will produce flyash with different chemical composition and properties than Power Plant C burning coal from Source D. Full replacement is seldom practical outside of lab experiments and niche one-off usages
The key is the collection of appropriate materials. Which will mean changing the way we handle trash. First change being the cost, which should be based on weight and or volume.
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It doesn't matter that there's not enough waste to replace all of the concrete use in the world. We just need to replace enough to make an environmental difference. If we use up all of the waste products available to make this stuff, we will not only drastically reduce concrete, we will have cleaned up all of those other messes! What's not to love?
Yes, I totally agree with you here.
It all depends on the cost of each alternative. Every decision is a trade-off.
it won't make a difference. missleading
What is the benefit of using hazardous materials for building living compartments? I don`t get that. The same goes for these plastic tiles which are produced in India. They are horrible for the environment, animals and for humans. We already have big issues with microplastics in the air, water and soil. Using a mixed plastic (because the melt different kinds of plastics together) for walking or street plaster, makes it even worse. The abraision will pollute the envirnoment much more than just burning the plastic using filteration for energy production.
I don`t get the ignorance on human pollution and why we always make things worse, when we try to fix things we produced in the first palce
@@michaspringphul The idea, I think, is to sequester the waste. It's there already, so better it be sealed into a form that it can't escape.
As for plastic tiles, they probably should only be used for low-abrasion surfaces, not floors. I can think of many possibilities there.
You have a valid point on how we always make things worse. I think it's because of the conquest mentality. We mess up by conquering something, and then we try to solve it by conquering the problem, and that makes still more problems. We have to learn how to think cooperatively, find a use for everything the way nature does, fit everything into its ideal place and not try to impose what works in one situation on some different situation (like using plastic tiles for flooring.) The waste isn't going to vanish--we have to figure out what to do with it.
I work at a steel plant. The slag is heavy. So much so that we smoked a cement truck trying to use it to make some of this stuff. We had a hose spraying the radiator to try to keep it cool. Not an insurmountable problem just need more powerful better cooled equipment.
Or you have to make and transport less of it at a time which means it is going to be more expensive. Unless people need specific properties they don't want to pay more.
You jacked a cement truck because the slag was too heavy?
Great presentation. I have worked on Fly ash based geopolymers and found interesting results. Every advantage you discussed is observed in the geopolymer. Now I am working on waste glass geopolymer, where we don't need Sodium silicate and also a low concentration of NaOH is required. Once standards and rules are established, I think geopolymers will be the future of building materials
Fascinating! Do you share your results on YT or another platform?
I sense a collaboration/promotional opportunity. Perhaps it's worth asking your bosses about promoting their research through well informed creators?
does super smooth texture of glass cause issues? Does glass need to be tumbled or blasted it be used in mixes?
can I ask for contact ?
Would you consider doing a video on cost/benefits of historical preservation versus tear-down/new building construction? At what point is a building too far gone, or it’s purpose too inefficient to preserve? What are other ways of preserving buildings while also accommodating contemporary community needs? I remember a sky scraper on Sansome Street in San Francisco that preserved pieces of the street-level facade, while replacing the entire original building with a new skyscraper. Love your videos!
That would be a great topic to talk about.
I would suspect that there are too many factors to come to a generalized conclusion comparing the two. How degraded is the plumbing system; how outdated is the electrical configuration; what type of foundation does the building have and what condition is that in; how efficient is the insulation of the building; is the building still structurally sound; what zoning regulations have changed since the building was first constructed; what is the intended use of a replacement building. The list goes on, and any one of those variables on its own could make or break a decision to retrofit vs rebuild.
@@DryBonz1 - there are also differences in "feel". Somethings about an older structures with their old growth wood, lime plaster, milk paint and Tung oil as opposed to laminates, partical board, synthetic stone, polyurethane and latex paint.
San Antonio tried to rebuild/replace 70 year-old dilapidated, crime-infested, low-rent neighborhoods. Police departments in nice neighborhoods fought the projects because they didn't want the displaced crime and drugs pushed into their areas.
There are almost no more available Fly ash or slag (GBFS) in the European market, as it is already in use in cement and concrete. In many ways we already have a semi-geopolymer concrete in the market. For instance, in the Norwegian market the standard cement has 20 % fly ash, and another has 70 % slag.
Yes, Geopolymerconcrete will be more common, at least in some more specific applications, but it is still much more important to reduce environmental footprint from the ordinary portland cement production.
Like bruh, în my area used to be a huge land fill of fly ash, not any more it îs all concrete and cinder Blocks now.
Maybe ground up wind turbine vanes?
Not to mention that all that fly-ash is a by-product of carbon-intensive and unsustainable processes in any case.
The fly ash isn't relevant. It is the polymer bond. Geopolymer is typically a OH hydroxide bond. Portland cement is a calcium bond. Two very different materials.
There's an organization in Alaska experimenting with silt and mine tailings (instead of fly ash).
Pretty cool 😎
Greatly explained :),
And also the scanty supply of source materials for Geopolymer concrete synthesis you talked about is a major Impediment to its large scale applications...
Thats exactly what we addressed in our research here at National University of Sciences and Technology, Pakistan,
We replaced fly ash with newer source materials i.e. agricultural waste ashes (they are also rich in alumina and silica and thus conducive to Geopolymer synthesis)
We found that strength remained intact for upto 15-20% replacement level
Very cool! Thanks for sharing, Mohammad.
Any thoughts on replacing steel rebar with lighter basalt rebar? With the reduction in weight, walls can be thinner, further reducing the amount of cement in a structure. Also, basalt would never rust.
@@ravenousvisages sounds like a great idea
I am going to start my masters thesis on geopolymer concrete. If they have made this material and has also been applied in the world, what do we need to research about?
@@maheendaud7615 well there's plenty of things yet to discover, like you can use some newer source materials instead of fly ash for example rock based geopolymers are very interesting
Also you can explore synthesis of chemical activators from waste materials for example sodium silicate can be derived from biomass waste and used as an activator,
So if you read the latest papers you will find the current research trends and a ressearch gap for your thesis as well
Looks like these waste products come from processes which also need to be heavily reduced or eliminated.
1. Burning coal is maniacally bad.
2. The process to get metakaolin are very energy intensive itself.
3. Slag has the same problem, though steel production seems unavoidable. One barrier is that it has many other useful applications.
4. The environmental problems of palm oil production are well documented. I also hope that we learned from biofuels that competing with food is not such a great idea.
Interesting presenation Belinda! What is the cost of geopolymer concrete compared to conventional concrete?
As someone who had permanent eye damage from sodium hydroxide burns, yeah, the liquid component of geopolymers is nasty stuff. That the activator is a corrosive liquid that requires separate packaging is a logistical hassle, too.
Caveats aside it's a useful engineering material that can be applied in certain niches. As a spray-on foam fire barrier it's hard to beat, and combined with construction methods like monolithic domes and non-metallic tensile reinforcement like basalt rebar, can make long-life low maintenance structures. A monolithic-geopolymer-basalt dome could probably last longer than the Pantheon.
Is there anybody building yet with thin skin eggshell spray applied multiple layer building technique?
@@thomasstebner7579 Search terms like "monolithic dome", "basalt fiber", and "aircrete" will return a lot of interesting links.
Ty
I really appreciate your time and effort to objectively talk about the pros and cons of various building materials. Very informative. Thank you.
I suspect a more significant barrier to replacing Portland cement than manufacturers is that architects and engineers want to work with proven materials.
yes this seems to be the main challenge.
Hey Belinda,
Your videos are really informative. Yes Geopolymers are really versatile material. I am an architect doing research in the subject. I've been to the Geopolymer Institute in France to attend GP camp in 2018 and had interacted with Prof. Daviodovits. The potential in India is immense as we still have coal power plants, but I think suitable thermally activated Aluminous and Silicious materials can be found anywhere in the world. Some of my friends who attended the camp in 2018 are experimenting with bottom ash of incerinators. Portland cement has been, over the centuries, standardized. GPC is still very new in that respect. But I am sure that standardization will happen. I recently came across a paper from Arizona University which explored the total replacement of virgin aggregates in GPC. The developments happening all over the world in this field is really exciting.
I think you should do a video on other uses of GP like LTGS for making stabilized soil blocks and high strength ceramics using GP - both lesser explored possibilities, especially the ceramics.
There is no question that humanity will have to manage their resources better if we expect to remain on this planet.
What a nice summary and introduction in the pros and cons of geopolymer's.
Last year I discovered Polymeric paver sand and just loved what you can do with it.
By framing my paver patter, adding colored stone, brushing the sand between the gaps, sweeping off the surface and adding water, can create some artistic designs, such as walkways, that are not only lovely to look at but are waterproof and will last for years. Thank you Ms. Carr for your presentation and insights in this emerging technology. Nice job!
The long term durability of roman concrete apparently involves the use of volcanic ash which reacts with salt water creating a harder material. The fact that this sort of chemistry isn't used to reinforce the concrete that we use is kind of silly. Granted volcanic ash is hard to come by unless you're near a former volcano, the fact that simple and basic chemistry isn't used more often is interesting.
Simply because we'll do stuff like taking steel rebar and dipping it in plastic in attempt to prevent galvanic corrosion, but ultimately end up exacerbating the issue even further by focusing all the corrosion in specific points.
Epoxy rebar is a non starter. That stuff is dreadful by trapping moisture against the steel.
Phosphate solutions are gaining a lot of traction for bridges and highways.
Definitely sounds like it would be best used in the applications it most excels in, to the extent that the relevant waste streams can support, rather than as a general purpose concrete. Perhaps some of the businesses already in the industries that manage those waste streams could be given tax incentives to make partnering with the businesses that utilize those byproducts more lucrative and cost effective than just letting it sit there. Sometimes it just takes a little grease to get the wheels spinning in a new industry, especially when it encroaches a bit on the territory of an old industry. Great topic, editing, and presentation - really like your shirt, too!
Fly Ash is usually used in northern climates instead of salt during the winter. Fly Ash was used in IL. in the 1970' & 1980's. Using Portland cement & aggregate ( sand & rock) can be poured in all the types of weather. I have poured concrete in the middle of winter in northern IL with no adverse effects. Concrete is a better way to pour highways, bridges, & over passes than asphalt.
What is worth to consider it that cement manufactureres such a CEMEX are incorporating more and more waste materials into their mixes, the concrete then still fits into standard regulations and behaves similarly. Meanwhile it still gains some of the advantages geopolymers have. The content of portland cement in cement is therefore sinking. I think in europe we have seen a supplementation of 25% in the last 15 years, at somepoint as Belinda mentioned the supply of flyash etc will be exhausted.
Great presentation. I have worked with Geopolymers and I know that material have many advantage versus Portland Cement, I think geopolymers will be the future of building materials
I firmly believe it's not the materials, it's how we've chosen to use them and our lack of adaptability or willingness to change. Your videos are fascinating and I always learn something. Thank you. :)
I wouldn't worry much about sodium hydroxide. Portland cement is plenty caustic as it is.
While using SH to dissolve silica into sodium silicate happens at very high pH, the product is not.
I definitely understand that as we (hopefully) move away from coal/palm oil and toward more sustainable renewables the raw materials for geopolymer will also decline.
I'm not an engineer, so I never factor concrete for tensile strength. I'd be interested to know just how different geopolymer is in this regard.
Fly ash is nasty stuff, but I can see it being used for applications you mentioned like sea walls and road beds.
Thanks for bringing up the topic. 🙂
Any geopolymer seller would most likely already mix the SH with silica to the Best ratio that is not caustic. SiO2:Na2O ratio above 1.5 should not be caustic, from Wikipedia.
Thank you so much for the expertly crafted content! You're brilliant at conveying complex topics and I appreciate above all your commitment to earth-conscious engineering.
Exactly. Except the "carbon emissions" hoax that some billionaires sold as true to the general population (to collect carbon taxes).
Hi, geopolymer fan here. I would like to add that one of the most common raw material for geopolymer is ferro-kaolin (an aluminosilicate source). They could be used to make ferro-sialate geopolymer. They basically exist everywhere. It's not the aluminosilicate that is rare, but the alkali metal that is crucial for the chemical reaction. There's only so much salt in the world and producing sodium hydroxide in the scale required to make geopolymer as common as ordinary Portland cement is just too expensive. But researches have shown calcium in ggbs form can substitute some of the sodium/potassium in the reaction, and 1 atom of calcium can replace 2 of them. So it IS possible for geopolymer to replace Portland cement. And sodium hydroxide is rarely used directly on site if you are talking about commercial products. Any geopolymer mix designer that is aware of the danger of NaOH should have design safe and ready to use solution of sodium silicate or potassium silicate
Great explanation Nedi, also laterites are a very good source for ferro sialate geopolymers
The biggest drawback is that fly ash is radioactive, you would be building structures that produced massive amounts of radon gas. My company looked at using fly ash back in 2007, we went with other geopolymer mixtures, steer clear of fly ash.
Would that still be an issue for structures like motorways or airport runways? Places that are well ventilated and where few people are walking around on them? Just trying to think of best-use scenarios. The more we can turn waste into useful products, the better.
@@WavegirlThinks I think if you do structures on that scale with a product like fly ash you have to control leaching into the ground water, air quality. I’m guessing heating it would cause it to off gas even more, places downwind of airports would have noticeably higher radon levels I’d wager, “might be EPA safe levels, I always question if their levels are applicable to newborns.” Some things really just need to be contained and not put back into the stream of use, I believe fly ash is one of those. Joseph Davidovits has many geopolymer recipes, My company’s been working with recipes based on his research for almost two decades, we incorporate aeration methods and more modern additives like silicon carbide whiskers. Geopolymers are the future, but we always have to look at everything we’re putting in.
But kaolin is not tho
@@nedisawegoyogya yeah, he was saying how he uses other biopolymers but not those that use fly ash.
@@nedisawegoyogya There are dozens of geopolymer recipes in Davidovits book, and many old Roman concrete recipes that do the job. I just wanted to warn folks about fly ash products, there have been companies slinging that toxic trash at people for decades now, it’s a crime that our children will pay for, radiological decay rates shouldn’t be a factor in your homes construction.
There might actually be cause for some concern with geopolymer cement, the long life span might mean the particulate formed from the natural erosion gpc might become a breathing hazard and impossible to clean up if adoption reach the level of Portland cemen. Just a conjecture on my end though
When adding waste materials to concrete mix, is there any concern about volatile chemical off gassing that would endanger inhabitants?
And how much of these specific waste materials do we actually produce in the associated industries? How much concrete could we make with our existing production, as compared to avail cement?
With fly ash and slag, both are created at high enough temperatures that any volatile compounds that may have existed in the raw materials are completely burned off.
Your voice over work is EXCELLENT!
100 year lifespan of cement? I've seen it crumble after 20-30 years! Then again, Roman cement remains loadbearing after 2000 years...
YES ! Egypt pyramids for sure , a worthy subject and an interesting one too ! ---- a big THANK YOU for all your quality work , KEEP SHINING , KEEP SMILING & KEEP SHARING THE KNOWLEDGE --- from Canada J.
This is the single most important topic on the table today, with relevancy to every human on earth. Thank you for posing such a concise explanation, of the technical aspects. So I must interject, that while Potassium (K) is usable in these equations, this is not a wise use of Potassium. Sodium based Geopolymer is just as good as Potassium laced GP, and conserves potassium for use in Agriculture. The use of Geopolymers is predicted to grow exponentially over the next decade. If we do not, there are going to be some serious short term and long term health issues for all humans. Over the last two decades, the worldwide average Oxygenation level (expressed as an overall percentage) has dipped over 1%. This is due in large part to the release of CO2 during the creation of Portland Cement.
I propose a mandatory moratorium on construction projects which require Concrete. if we take a break, and then limit the total amount of Concrete which can lawfully be produced worldwide, we will have a solution. This requires a massive international effort, drastic steps, and severe economic and legal consequences for individuals and organizations whom will inevitably skirt the laws. Personally I can tell you without batting an eye that China is out. They will likely never fully modernize, until long after it is too late.
But the rest of us can use this GP as an intended Gift from above. People need to begin to think in more sustainable context. The widespread new construction wave that has spread worldwide is choking the air, polluting the water, and causing material shortages in every market. Next year over 20 Million people will die prematurely due to chronic lung conditions caused and exacerbated by poor air quality, smoke, contaminants, and low Oxygenation levels. This could have been prevented if Davidowitz's theories had been properly pursued in 1979. It is a truly shameful state of affair, that corporations are permitted to shape the course of humanity. Even worse that they choose to ignore their responsibility and pursue deadly policies of using toxic garbage to manufacture the fake reality we have become trapped by.
As a Construction Inspector and Energy Consultant in Southern California, I spend half my workday on construction sites. This week alone I have been out to over 40 sites. I am witnessing the use of GP in decorative and non weight bearing applications already. In fact many builders are using "GP mix kits" purchased online to make Fake Granite, Faux Marble, even Synthetic Diorite. My suggestion is that Builders mix fly ash, slag and waste ash together to make a contiguous mixture which may be easily replicated in the field. Fly ash can be added to conventional Portland cement to stretch the recipe. This was common practice until more research was done. So, it turns out Fly Ash and slag benefits the overall mixture considerably. The addition of ash to cement increases strength while also adding moisture resistance, it lowers the heat of set, increases plasticity and decreases the water need. The result is a concrete that is harder, stronger, more water tight, and requires less to create. In Southern California we use 13% Fly Ash by weight. This mixture is a level which was agreed to by many parties, regarding many factors including cost, time, and usability.
However this is just a drop in the bucket. Lowering demand is the long term solution to the concrete problems. No matter what certain products will have to be made from scratch, even with GP. So we have to change our thinking about what is and is not necessary to build. If we do absolutely have to build something, maybe we can scale it down a bit. DO we really need more lanes on the freeway? How about going to work from 10 to 7 instead of 8 to 5? Little things add up...
I have done my research in MUET, Jamshoro Pakistan on geopolymer concrete by using local NaOH as alkali activator instead of using laboratory grade NaOH since it is very costly and less market supply as you discussed in this video. The results i got from this research were seem very good as compared to conventional concrete.
It is an intriguing concept, and does seem like an opportunity to mitigate the environmental impact of concrete somewhat, but the availability problem definitely limits how much we could invest in it as the future of concrete, particularly since one of the sources of waste material are coal power plants, which are just another environmental issue that we want to scale down rather than up.
You are absolutely right collin, the scanty amounts of source materials is a major issue, and recent trends of shutting down coal power plant has further exacerbated the issue...
We at National University of Sciences Technology Pakistan conducted a research on newer source matrials of late,
And found that agricultural waste ashes are conducive to Geopolymer concrete synthesis as well, principally due to high amount of amorphous alumina and silica
Excellent presentation! I always learn so much from watching Belinda Carr's videos. I think the Canadian company Plaex is using this type of product in their composite block system.
2:20 fly ash use is forbidden as a concrete filler in german... for the same reasons you made up for it's use.
We thought asbestos was a good material, I don't want to know how bad these waists could be in our walls...
I find the subjets and the manner in which you present them to be very interesting and pleasant to watch. All the best to you and thank you. Dave & The Girls
Thanks a lot, Dave (& the girls)!
Thanks for the heads-up! 🙏🏽 💪 Maybe Geopolymer cement can also make infrastructure (e.g. bridges and skate parks) more affordable.
Strange that bridges and skate parks are your touch points….
I was not anticipating seeing one of the OG’s of Internet history on this niche of a video but I’m not against it.
Probably not cheaper, unless energy is artificially expensive.
For bridges geopolymers are bad choice where ever winters are below freezing temperatures. The geopolymers I have tested at work do dot endure freeze cycles when there are any salt present.
These are not good for infrastructure.
Thank you for showing the negatives along with the positives excellent video I appreciate the hard work very educational
Thank you, Andrew!
excellent presentation Belinda......very informative ...well done young lady!!! bravo!
Love what you Belinda. Don't stop. I only see quality on your channel.
Thank you very much!
Thank you for sparing us from the surprisingly complex chemical details and using a quick summary instead. I’m particularly interested in the fire resistance and insulating qualities of the air containing formulations. We really need non-flammable alternatives to traditional construction materials like wood and pvc lumber. Fire danger is increasing ever year and it’s become a surburban issue, not just a wildland-urban interface problem. Blowing embers can go anywhere.
Coal ash? So the idea is to take a toxic waste product that nobody wants, sitting in special landfills around the country, loaded with radio active elements, heavy metals, and add that to my foundation or slab? Why don't we insulate with some asbestos residues for good measure, can't wait to invite the grandkids over. PS: I do like your videos.
There are radon barriers used in new construction.
@@MadLadsAnonymous made of plastic and all inevitably fail
Great feature as always Belinda... thanks for this!
Thanks, Stephen!
Brilliant, thanks, I knew nothing about this and that's pretty rare when I've never heard of something
I've also thought about the blocks on the pyramids being poured-in-place as opposed to mined from a quarry. It makes sense, considering the weight of each block.
There really are several big problems with the idea that the blocks were formed in place.
1. The quarries from which the stones came have been identified. In at least some cases there was writing documenting the pharaoh of the time.
2. There are Egyptian depictions of blocks being transported on sleds (with a man at the front pouring a liquid onto the sand).
3. Then there is the documentation from Merer. The oldest known papyrus (dating back to the time of Khufu) is a sort of diary/accounting for the activities of his crew and how they transported casing stones from a quarry to the area of the Great Pyramid. Interestingly, his notes were found far from where his casing stone activities occurred - it seems likely that he had transported his boat to a different location to support copper mining/processing.
There area lots of things we don't really know about the pyramid construction (heck, there is a void in the Great Pyramid which we don't know how to access). But we do know that the stones were quarried. It is also quite clear that a good portion of the construction was not of precisely fitted stones - and there is (IMHO) good reason to believe that a whole lot of the more central volume of the Great Pyramid is debris from the quarrying.
The idea of stones formed/poured in place is attractive but it is inconsistent with what has been learned over the years.
@@oldguy1030the great Pyramids are over 10 thousand years old ..the real people who built them where long dead before those depictions existed ..they discovered them not built them..to put it short there is no way those blocks can be pulled ..they where built on site
@@ProblematicT9k pyramids are not 10000 years old. this is just a fantasy that you've seen on some clickbait documentary made for gullible people. oldguy1030 is citing actual science, which rejected the cast block hypothesis decades ago. you should learn how to cite real research yourself
You have an amazing channel! Keep up the good work! And yes the Pyramids are always interesting.
I just saw you featured on Vox channel, so proud your channel now hits 200k subs! On your way to a million soon. Go strong girl!
Excellent video. Up here in Canada, our team is working on developing a locally sourced geopolymer cement formula for use in 3D printed concrete houses!
How do you guys ensure that proper adhesion happens on stacked layers especially with no rebar. No offense as I don't know your company, but a lot of companies in the game seem like their teams have 0 experience in the construction world and are trying to solve problems that don't exist.
You know that story about British colonists putting a bounty on snakes to reduce the snake population which led to people breeding more snakes for the money? What if this gets super popular and the ingredients stop being byproducts?
One of the interesting ideas Bucky Fuller came up with was prestressed concrete for highways. Bolted together on substrate. It provided better performance and easier repair/replacement. I’m wondering how geopolymers would work in this environment?
You provide such great material to your viewers. I appreciate all the hard work you put into it. It's a truly wonderful channel!
This video really cemented the point
Lol!
Perhaps Govt incentivised initiatives under waste reduction/recycling could require that this material be exclusively used in Govt only projects where tax breaks can also be given to raw material producers within reasonable proximity to projects. That way, the Govt is playing the role that it should really play; doing the right thing in the interest of the future and its people.
Yeah, that's not governments appropriate role. It should defend the weak, inhibit crime, and regulate trade. That's it. We can take it from there.
Wagner's - developers of Wellcamp - have been in polymer cement for years. They also manufacture fibre reinforced plastic cross arms for power networks.
I would love to hear more about the geopolymer theory of pyramid production - it sounds really cool!
Great video, All the doubts cleared also explained the advantages and disadvantages of geopolymer. Love from @India
The Romans are probably scoffing in their graves seeing us still trying to figure out concrete that can last 1000s of years
It's already been said Roman concrete might just be survival bias. As in there is plenty which didn't last, we only see the ones that survived
Production of the waste materials currently used for making Geopolymer cement is in rapid decline for good reasons. Has any work been done on finding an alternative primary source of silicates and a process that is scalable and environmentally sound?
Rice husks are high in silica.
I can also see bagasse supplementing the rather more onerous palm shells for some of that high carbon ash Belinda mentioned.
Belinda should do one on hemp crete. Very sustainable and can reduce not only water consumption but has a net zero carbon emissions. I would love to here your pros and cons on the matter.
Recently there is also Ferrock a mix of Steel Slag & Crushed Glass powder what I like about ferrock is it doesn't look like gray concrete it comes out many shades of iron reds and also sometimes layers turn out to be black
Ive subscribed to your channel because of the fine amazing construction information that is provided. Thank you Belinda
Just like Belinda mentioned, it does sound good, but it's made of ingredients which all come from industrial waste, which means the suppy of it is limited by how much can you get. However you can get cement anywhere, just do a little digging, do a little burning, and a little mixing! I can't imagine my country getting Metakaolin, and we don't have coal power plants here to get the fly ash.
Well you can also synthesize geopolymers using geological resources like calcined clay and laterite, these are prepared at temperature 3 times lesser than that used for making cement
really enjoy this educational video, this sounds like a no-brainer for a lot of different applications, if not all.
Really great video. Had never heard of geopolymer cement before. Sounds like a really enticing material.
In terms of things like fly ash, there are significant inclusions of radioactive and other problematic materials such as high arsenic and mercury compounds. What's the purification process for this (e.g. do they remove the toxic materials)?
As well, has anyone done a material degradation test in terms of use in roads and other high-abrasion situations where geopolymers are ground down from their original construction and leach into the environment?
I'm also curious about what happens when the building reaches end of life and is torn down.
recycle and rehabilitation@@szurketaltos2693
Sounds like similar materials to glass- this would pair well with basalt rebar. Since basalt is essentially a glass fiber stronger than steel rebar per weight (basalt is much lighter), constructed wall and deck thicknesses could be much thinner. This in turn would mean every 3 tons of cement could be displaced by just 1 ton of geopolymer. Skyscrapers, bridges, dams, large public works, should all be the ideal target projects. How about desalination domes in the middle of the Sahara, and giant aquaducts linking Mauritania to Egypt. Such a project to green the Sahara could end poverty in northern Africa, providing a backbone for a linear city and ending world hunger with adjacent agriculture land watered with solar distilled seawater, despite global warming. Any potential for a translucent geopolymer?
Would the combination make a 'mythical' 'everlasting' concrete?
Definitely would like to have a better understanding of costs (knowing that economies of scale would control or reduce cost eventually). Seems like there are enough current applications where it could continue to prove itself as a great way to use waste materials. Thanks.
Fly ash has long been added to concrete. When Jeffrey Energy Center was build unit #1 was in service when concrete was being poured for unit #3. They mixed fly ash from #1 into the concrete for #3.
You're thumbnail intrigued me enough to not just scroll by. Then i realized it was you. Been loving the videos. Hello from Long Island NY 👋🏼
Thank you! I considered make another silly thumbnail pointing to the geopolymer print, but decided against it. I really don't know what the magic formula for a thumbnail and title on YT is.
Fly ash is infamously very toxic, mostly bc of all the heavy metals. It feels strange to not comment on the safety of using it as a material in close proximity to humans even if it is encapsulated?
Steel slag is also pretty shit afaik.
Has there been any long term studies on this?
I like the idea of light-weight concrete for a residential roofing alternative rather than asphalt/petroleum, as asphalt roofing has a limited 15-25 year life-span before it needs replacement.
I know there is metal and ceramic roofing but I like to know we have other options.
Waste salt for waterproof building materials by Israeili University is being worked on. Plus Eric Geboers and The Salt Project needs waterproof coating material that should be available made from algae or existing chemicals.
It's great to learn more about this polymer concrete. In colder regions, we are unable to make our roads from traditional concrete largely because of frost heave and water damage, so it would be wonderful if the characteristics of this type of concrete could give us options. Cost is always an issue, though...
I live in a northern cold region - we use asphalt because it is easy to repair - has decent water dispersion and can expand/contract alright without much cracking.
@@corail53 Exactly! But asphalt is also energy intensive to produce, reliant on fossil fuels, and has a short lifespan. In areas with a lot of traffic, the asphalt can last less than two years causing a permanent disruption to traffic over a small area. I also worry about leaching benzene into the water table.
Thanks Belinda. Another amazing video!
A brilliant use of a waste product/s, that said we should be looking at the cause, the originators of the waste and finding alternatives that don’t produce the harmful waste products.
Magnesium Oxide is the most significant cement in history. It should be mentioned as a geopolymer. There is more than enough of it to replace Portland cement. It is non-toxic. It has fabulous properties. It probably deserves a month's worth of episodes.
I'll look into it. Thanks!
What about sea-crete, made from electrically charged nets in ocean water drawing and solidifying carbonates? If it can scale, it is a huge carbon sink, itself a suggested method for carbon sequestration.
Maybe lobby large retailers like Menards and Home Depot to carry it for small scale residential use. As an engineer the concept is very interesting. Anything to reduce landfill usage. On that matter I believe we should burn our garbage to extract the energy as opposed to landfilling it.
Additional things to think about with fly ash are the minor constituents depending upon the specific coal bed composition but may include one or more of the following elements or compounds found in trace concentrations (up to hundreds ppm): gallium, arsenic, beryllium, boron, cadmium, chromium, hexavalent chromium, cobalt, lead, manganese, mercury, molybdenum, selenium, strontium, thallium, and vanadium, along with very small concentrations of dioxins and PAH compounds.[1][2] It also has unburnt carbon.[3][4]. Source Wikipedia
You forgot uranium daughters. It definitely releases radon.
Definitely make a video about the theory that Egyptian pyramids were made of geopolymers. If you touch on or go deeply into other possible sites using geopolymers so much the better. Fascinating.
Thank you for vid, i used to follow Davidikus always wondered how the limestone blocks they made a few years ago in paris are doing. Could be another part of your Egyptian themed video. Take care
05:48 The reagent there is in a plastic jug. That plastic use is a downside right? (Traditional cement can ship in paper sacks)
5:49 the calculation is the same.
0.9 / ton for a component mixed 1 to 5 parts
vs
2 part mix at 0.2 that you need 5x the quantity of.
before mention of the substantial difference in price.
They are both good, but not the same thing.
we need more plants, rather than more plant based concretes
How do the know the mass of all living things? I wanna see their calculations 😑
Hey Belinda, I just stumbled across your channel and this is very informative. I would love a video on the egyptian geopolymer pyramids theory please :).
1. You may wish to explore Basaltic Fiber rebar, reinforcement bars made from fused bundled fibers drawn from melted basalt.
This type of rebar does not corrode, so when water penetrates the concrete the rebar does not expand from rusting, thus eliminating or greatly diminishing one cause of failure of modern concrete.
2. Yes, a video on the theory of cast geopolymer stone in construction of some of the pyramids would be interesting.
However you may wish to take note of the remains of a form of windlass and of what is called Petrie's Cradle.
With these devices many of the stone blocks could have been rolled into general position.
Quite possible that several types of methods were used. Interesting.
I am starting to replace the roof on my house in Portugal as have a lot of people. This leaves me with a lot of old terra cotta tiles waste. I was wondering about doing vegetable growing in an inert material rather like hydroponics. I though oh I am going to need tons of the stuff. Then the penny dropped crush up the tiles. Now it occurs to me that I could crush them up for concrete for low stress jobs. This could go on forever.
Enjoyed your presentation, thank you very much.
a video on historical geopolymers used in south and center america would be lovely
What a great job on this presentation!
Thanks, Peter!
It is important for people to understand the difference between the CO2 that is produced in the cement making process, and the CO2 that is produced from oxidizing carbon (burning fuel):
CO2 produced by burning fuel gets its Oxygen from the atmosphere, and that O2 will not return to the atmosphere unless it is photosynthesized by terrestrial plants. It has no net change in atmospheric density. Following photosynthesis, the carbon that was extracted from petroleum or coal becomes soil organic matter, a resource that is in desperately short supply.
CO2 produced by making concrete liberates Carbon and Oxygen trapped in carbonate rock - 'fossilized air', if you will. Both the Carbon _and_ the Oxygen that were lost from our atmosphere when the rock was formed are returned to the atmosphere: This results in a net gain in atmospheric density and pressure. When _this CO2 undergoes photosynthesis, we get some of our atmosphere *back.* As is the case with carbon from oxidizing fuel, the carbon from making cement will become soil organic matter.
Currently, our atmosphere is a little too light for optimal human health - about 133 *trillion* tons too light - and we are constantly losing atmosphere. Geopolymers may be better than cement in some ways, but they do not replenish our atmosphere in the way that making cement does. Breaking up monopolies, and in particular, removal of code restrictions will create more opportunities for the making of conventional cement (which helps to improve the atmosphere by releasing fossil CO2, as previously stated) as well as geopolymers, that sound wonderful for disposing of waste materials - many of those same waste materials can be cast in cement blocks, as well, for that matter.
Very nice video and analysis. Must focus topic for the future. Greetings, sustainable solutions engineer
Absolutely fascinating, truly the future of construction. Thank you for sharing and all of your hard work. PEACE and God bless.
Geopolymer institute is a great resource
Actually PFA and GBBS are commonly used as additives in cement and concrete products in markets where they are economically available. A reason their usage is limited to being an additive instead of a direct replacement is because as waste products, their chemical composition will fluctuate. Power Plant A burning coal from Source B will produce flyash with different chemical composition and properties than Power Plant C burning coal from Source D. Full replacement is seldom practical outside of lab experiments and niche one-off usages
Awesome video and commentary 👌
You're a really good teacher, thanks!
Could this be sprayed like gunite or other spray type concretes for monolithic domes?
Thanks again, Belinda! ❤
Great video, very informative!
The key is the collection of appropriate materials. Which will mean changing the way we handle trash. First change being the cost, which should be based on weight and or volume.
Very awesome video. More on geopolymer concrete please