Are we stuck with cement?

https://theoutline.com/post/5124/are-we-stuck-with-cement-environmental-impact

by sus_007 • 8 years ago

161 93 8 years ago

adrianN2• 8 years ago

We just need a carbon tax that appropriately prices the pollution in. Just set up a market where people can trade carbon and companies can make money by sequestering carbon out of the atmosphere.

gmueckl• 8 years ago

Sequestration should not be part of a market for CO2 certificates. Sure, you could earn money by sequestering CO2 and selling certificates generated by the process. But you will have to buy them back when the CO2 leaks. And it should diffuse out of the atirahe over time, albeit slowly. So you might eventually have to buy back the certificates instead of earning the money required to maintain the filled up CO2 storage for, well, virtually forever.

vpribish• 8 years ago

that sure seems like it's workable though. take the money, invest it, pay out later. like a bank, or an insurance company.

Fjolsvith• 8 years ago

So a company that plants trees could earn money under this system?

amluto2• 8 years ago

It’s not at all clear to me why carbon trading is useful. If a ton of CO2 emission is taxed $5 and a ton of capture is credited $5, what’s the point of trading certificates?

phamilton• 8 years ago

My understanding is that with hard caps on CO2 emissions, a market rate for carbon will emerge. In other words, if you can buy a maximum of 100 tons of CO2 emission for $5/ton via a government agency, then at some point you'll have to buy credits from other parties, and that'll command a premium.

earthboundkid• 8 years ago

It helps ensure that the financial sector controls everything in our economic system by giving them an excess of money that they can use to buy politicians.

stevesimmons• 8 years ago

... because the people doing the emitting are different from the people doing the capturing?

IkmoIkmo• 8 years ago

How I understand it is this:

Everyone creates 100 units of pollution together, say ten firms producing 10 units each.

Then they say, you can only use 90 next year, 70 the next decade, 50 the decade after.

Everyone needs to reduce pollution a bit, this is hard. Some have a 50 year investment in a factory that they can't remodel to pollute less. They'd need to shut down.

Others are more flexible, they can remodel existing infrastructure, or shut down ones that are near the end of their lifetime. But why would they make investments in something more clean?

Trading means one firm producing 10 units can invest in efficiency. Next year it's allowed to produce 9, but its new tech only produces 5. It can sell the other 4 to four factories which couldn't reduce their emissions from 10 to 9.

Over time the polluting parties have funded the non-polluting parties' clean technology, while over time the total pollution has gone down. Moreover, it'll incentivise the lowest-hanging fruit approach, i.e. reduce emissions where it's cheapest to do so, first.

That's why it's called cap-and-trade, not just trade.

skosch• 8 years ago

Fortunately, the political will for carbon pricing is growing. The one obstacle is that conservative politicians are scared of using the word "tax" – so the current strategy is to push for a bill that would return all of the money to citizens ("carbon dividends" are an easier sell than "carbon taxes").

Here are the biggest organizations pushing for this — support them if you can:

– https://citizensclimatelobby.org/ (strictly bipartisan)

– https://www.clcouncil.org/ and their PAC, https://twitter.com/afcdividends (conservative/industry-backed)

– https://allianceformarketsolutions.org/ (conservative)

– https://www.s4cd.org/ (campus-based)

ramchip• 8 years ago

The turbine will produce about three megawatts of energy on average which, when working at full capacity, is enough to power 2,400 U.S. homes for one month.

The "for one month" makes no sense here, but if you drop it the math checks out.

xyzzyz• 8 years ago

Additionally, it won’t work at full capacity all of the time. The capacity factors as seen in actual existing commercial installations usually range betweeen 40% and 60%, so the average power output here will be rather 1-1.7 MW instead of 3 MW

dredmorbius• 8 years ago

Clarifying further:

Megawatts are a unit of power. Think of the size of the engine in a car.

Megawatt-hours are a unit of energy. Think of the size of a fuel tank.

Both units are useful: if you run a 1 MW load (a synonym, mostly, for power) for an hour, you'll use one MWh of energy, and have to fuel or pay equivalently.

But increasing the size of your gas tank won't make your car more powerful, and increasing the engine size won't let you drive further between fuel stops.[1]

That serious information outlets still confuse the terms is a bit sad really.

_______________________________

Notes:

1. Pedants, I love you, welcome to Costco. But I'm excluding second-order effects, which tend regardless to be in the opposite directions.

cup-of-tea• 8 years ago

Or three times that many homes in Europe. US power usage shouldn't be used as a benchmark.

throwaway76543• 8 years ago

Where in Europe? There's a variance in the average consumption of over 400% depending on the weather. France uses much less energy than the US on average, but Sweden uses more.

We see the same variance regionally within the US as well. Canadians use more energy per capita than folks in the US. Cold and hot states dominate energy consumption per capita.

The US does have larger homes and more wealth and does tend to consume more energy per capita across similar environments -- but regional weather patterns create far, far larger differences in energy consumption than any other factor.

We could just as easily say that Europe shouldn't be used as a benchmark as the weather is too nice, on average.

amluto2• 8 years ago

It’s a thing. The article also talks about water pipes, “which leaks enough drinking water a day to serve 15 million households”.

Agathos• 8 years ago

Maybe it's poorly made and the blades will fall off after a month?

rini172• 8 years ago

I expected some estimate when the turbine generates enough energy to make the concrete instead...perhaps I have too high expectations.

kevin_thibedeau• 8 years ago

Facts would spoil the narrative.

Koshkin2• 8 years ago

Actually, it's "megawatts of energy" that doesn't make sense; home per month, on the other hand, is a valid unit of power.

Sharlin• 8 years ago

Yes, but "n homes for one month" is not home/month; it's home*month.

konschubert• 8 years ago

home per month, on the other hand, is a valid unit of power.

"1 Home” is already a unit of power. One home per month would be energy over time squared. :D

sandworm1012• 8 years ago

>And due to their lack of scientific acumen, they’ve focused on using different raw material mixers for cement which are introduced after the carbon intensive portion of the process.

That someone does not share your goals says nothing of their scientific acumen. There are plenty of intelligent scientists working in the concrete industry. Their priorities may be different, but they are not bad scientists.

Concrete is also a consumer product. Real change has to come from the architects and engineers who create the demand. But finding a true low-carbon alternative, a real alternative, is exceptionally difficult. Properly designed and maintained concrete structures can last centuries.

jessaustin• 8 years ago

Centuries? Doesn't the material lose much of its strength when the rebar rusts away, which it certainly does in a century?

coryrc5• 8 years ago

It doesn't have to; the deeper the rebar the longer it will last. Rust takes more space than iron, so it can't form if the integrity of the concrete is uncompromised. You have to weigh the extra concrete against the likelihood the structure will be obsolete anyway. Building a 4-lane floating bridge across Lake Washington that drains runoff directly to the lake wouldn't have mattered if it would have lasted longer because it was too small and environmentally damaging in other ways.

sandworm1012• 8 years ago

Many concrete structures don't use rebar. Only "reinforced concrete" worries about rust. A concrete brick is all but immortal.

mchannon3• 8 years ago

Galvanic protection prevents rebar rusting. In places like the Bay Area, if you look around major concrete structures, you'll see "anodic protection" plates on the ground which contain large blocks of zinc. As long as you keep that zinc block fresh and the circuit intact, rebar will never rust.

Some protection also uses electrical power. I seem to recall there's a bridge somewhere that uses solar power to keep its rebar from rusting.

crankylinuxuser• 8 years ago

“We have created the Ferrari, now we need to create the Ford,” Ulm said.

No, you put a racing stripe and a spoiler on a dumptruck, and then talked about its aerodynamic qualities.

Not all industries are happy about ecological actions. That game will have winners and losers.. The Earth as a biosphere will "win", but there's a lot of industries that lose.

Last I checked, the Earth's biosphere isn't paying the politicians. The dirty companies, well, they are.

realandreskytt• 8 years ago

Afaik the way cement works is you separate carbon from stone during its production and it binds co2 from air during setting. So wheres the big impact?

NegativeLatency• 8 years ago

The “separate carbon from stone” step is not 100% efficient

mchannon3• 8 years ago

It doesn't bind CO2 from air during setting- that's the disconnect.

By converting the carbonate to oxide, the calcium in cement is free to bond with silicates (and to a lesser extent other compounds).

That CO2 released during manufacture is now looking for a new home, which could either be a plant, or a weathering deposit of limestone which could use the CO2 in the air to convert its own carbonate to stable bicarbonate.

dzhiurgis• 8 years ago

At some point it must be cheaper to just cut a massive piece of rock and ship it to the construction site, isn't it?

Gibbon12• 8 years ago

I've wondered about that of late. Assuming that fitting stone work was is a skilled craft. But with modern CNC technologies might be worth a look again.

HeyLaughingBoy• 8 years ago

Depends. Are you taking into account reconfiguring bridges and overpasses to make the loads fit, or factoring traffic management costs into the equation? The truckloads of concrete to make a structure individually take up a lot less space and weigh less than the final structure itself.

timwaagh2• 8 years ago

im in, where can i buy this? where can i invest?

ah thats right...nowhere.

the problem is not the industry. the problem is the people who write this and complain about it have not taken any steps to bring these more sustainable cements to market.

aoner2• 8 years ago

The problem is actually the industry. Many companies have tried, but keep failing. There is a really insightful report why innovation is stopped by huge barriers in the industry: https://www.sciencedirect.com/science/article/pii/S221042241...

The development of more sustainable cements is a challenging but urgent venture. Demand-oriented knowledge formation and the reliance on existing prescriptive standards impede progress towards more sustainable alternatives to conventional cements. None-the-less the last years saw the emergence of a number of technology based start-ups with ambitions to introduce new low-carbon cements as alternatives to traditional Ordinary Portland Cement (OPC). An overall analysis of the Technological Innovation System for cement technology is conducted. This is extended with an investigation of how three start-ups, Celitement, Novacem and Calera perform within this environment. The implementation of new materials requires new types of collaboration between R&D and market actors, a combination of synthetic with the existing analytic knowledge base and redefinition of standards and norms. Moreover, a close cooperation of incumbent actors along the construction value chain is precondition for success of disruptive innovations.

timwaagh2• 8 years ago

oh pity. i figured they'd be just about begging for the stuff if it is reasonably priced since the millenials buying houses right now would be happy to buy anything that said 'built sustainably' if the price is reasonable. apparently it is not that easy.

mabbo• 8 years ago

There's a difference between a one-time cost and a variable cost. "Spending" carbon (via concrete) in order to reduce society's "spending" of carbon (via infrastructure improvements) should usually come out to a net gain.

It's an investment.

While I agree we need to include all costs in the accounting and improve the concrete industry as well, we shouldn't let the fact that carbon is emitted by concrete creation stop us from making these investments.

_jal• 8 years ago

Sure. Many things are. The question is not whether concrete is a marvelously useful material; the question is whether other materials might have fewer negative externalities without compromising function.

Note that you can rewrite that notion to discourage thinking about replacements for lots of things in the modern economy. Oil is a major input into nearly all other investments, so "spending" dino-juice carbon to enable everything else should usually come out a net gain, right?

madaxe_again• 8 years ago

This article talks as though Portland cement is the only cement. It isn’t.

I’ve spent the past few years working in my free time on the restoration of several old buildings, under the guidance of my wife, who is a conservation mason, much of which has comprised removing cement and gypsum plaster and replacing them with lime mortar, lime plaster, and other lime products as appropriate.

While it’s true that most lime products aren’t as strong as cement, and are permeable to water vapour, their CO2 impact is much, much smaller - and many applications which currently see the use of Portland could as easily use appropriate lime-based products. Breathability is a good thing in most structures - most damp that you see in buildings arises from impermeable materials and condensation.

As to strength, lime-Portland blends exist which can create impermeable and strong concrete with less environmental footprint, and I’ve been experimenting with mixing lime with various different aggregates and plasticising agents - resulting in some interesting materials - ground pumice and slate in varying proportions produce very strong (high tensile and compressive properties) and impermeable materials - I was inspired by Roman concrete.

Here’s a tiny bit of further info on CO2 footprints, from a company I’ve bought several tonnes of NHL from:

http://ecolime.co.uk/c02-quick-facts/

NeedMoreTea3• 8 years ago

Roman concrete also has loads of advantages over modern concrete. Cracks don't spread, better salt resistance, and better earthquake resistance.

Modern concrete will not survive like Roman examples have. With the environmental advantages too I'm surprised it hasn't had a resurgence.

rini172• 8 years ago

Can't find the source now, the problem is that Roman concrete hardens slower than modern one.

coryrc5• 8 years ago

They aren't comparable. The compression strength is too low to prevent oxidation of iron rebar (though epoxy-basalt rebar could replace), limiting you only to forms of ancient Rome: primarily vaults, domes, and vertical walls one or two stories tall (upon which wooden structures went higher).

You also need much more limestone because the material is weaker, incurring higher environmental impact that way.

sgc• 8 years ago

As someone outside your immediate target market:

1) what do you mean by single skin and double skin exterior walls?

2) are there any simple/quick and fast mixes to DIY a stronger lime mix?

coryrc5• 8 years ago

If you make a strong enough mix, you'll just replicate the existing problems with OPC. But generally, you can DIY a cement with roughly 1/3 hydrated lime and the rest graded dust-3/4" pozzolonic stone. Let me know the impact of acquiring that if you aren't in Italy or, apparently, southern Idaho.

You can do it with non-pozzolonic stone but using ~2:1 lime:crushed terracotta, but it won't have the magic healing properties of the original.

(Note, going off memory on the ratios; they're probably somewhat off).

coryrc5• 8 years ago

Using a naturally hydraulic lime is important for creating weaker joints, but it doesn't save that much CO2. You only heat the limestone a few hundred degrees cooler (though for longer) and you don't pulverize it as much, but hydraulic lime is using the minerals mixed with it to harden just like OPC (which is why it can harden in such thick pieces like the base of the Pantheon), not pull CO2 from the atmosphere like a non-hydraulic lime.

lpcam33• 8 years ago

It's time to question economic growth. We cannot change the whole economy with a green one, we simply don't have the resources. This is just one example of many. What we need it's to take care of what we have right now and create conditions for people to have a good live regardless the economy is growing or not.

maxerickson3• 8 years ago

First step to creating conditions for 7 or 8 billion people to have good lives is to massively grow the economy.

FooHentai2• 8 years ago

Congrats you grew the economy. Now you have 16 billion people.

Gibbon12• 8 years ago

Doesn't work is massively growing the economy pulls the roof over our head. Considering if we do the worlds poor are the ones to suffer.

That 3 bedroom ranch style house in Bangladesh doesn't help anyone if it's under 2m of sea water.

Turing_Machine• 8 years ago

The only possible way that the billions of people in the Third World will ever have anything approaching a "good life" is by massive economic growth.

philipkglass3• 8 years ago

The report exposes quite the paradox: We desperately need these infrastructure projects to transition to a carbon-neutral world, but in doing so we will have to emit a massive amount of carbon.

Massive compared to what? This article highlights that a single wind turbine uses a lot of concrete. But per the latest IPCC assessment, wind power over its life cycle already has the lowest median CO2 emissions of any electricity source. Sure, look for even cleaner ways to make materials, but this rhetoric is terrible. It lets fossil shills bludgeon you with your own words later: "see, environmentalists say coal burning emits massive amounts of carbon dioxide, but they say the same about switching to wind power, so there's no rush to change things."

Here's a recent review article about curbing CO2 emissions from cement:

Global strategies and potentials to curb CO2 emissions in cement industry

https://s3.amazonaws.com/academia.edu.documents/39977040/1-s...

It provides actual numbers and suggestions. Only half of cement's CO2 emissions per ton come from the chemistry inherent in calcining calcium carbonate to produce calcium oxide and carbon dioxide. The rest comes from the fossil sources of energy used to process materials. Like most industrial processes, it can cut emissions significantly just by switching input energy sources. Also, as someone else mentioned, concrete absorbs atmospheric CO2 as it cures. It's mostly the fossil combustion embedded in its production that drives emissions over its full life cycle.

pstuart• 8 years ago

If that CO2 is going up a flue it should be possible to capture (yes, more energy required).

philipkglass3• 8 years ago

As mchannon comments, concrete does not absorb a significant amount of CO2 as it cures. I was mistaken. The calcium in lime forms silicates.

However, it remains true that half of the life cycle emissions of concrete come from fossil combustion. Replacing fossil combustion with other energy sources can cut concrete's CO2 footprint in half without any major changes in concrete's composition or use.

quotemstr3• 8 years ago

Agreed. It's foolishly short-sighted to worry about the one-time construction emissions of a facility that can go on to produce power for decades. It's frustrating to see a segment of climate advocacy motivated not by quantitative concerns regarding radiative forcing, but by an aesthetic opposition to industrial civilization itself no matter what form it might take.

philipkglass3• 8 years ago

I find the "deep green" collapsitarians awful. But I don't think that's where most of this counterproductive hand-wringing comes from. I think it's mostly due to crippling innumeracy. People apparently lose the ability to do arithmetic or compare numbers once the numbers get larger than the price of a house. Words like "massive" get overloaded to describe phenomena separated by multiple orders of magnitude.

How much carbon dioxide is emitted during a wind farm's construction?

Massive.

How much carbon dioxide is emitted by fossil-fueled automobiles?

Massive.

How much carbon dioxide is emitted by unused cell phone chargers that are left plugged in?

Massive.

The United States stops driving fossil fueled automobiles and unplugs its idle cell phone chargers. How much does it reduce CO2 emissions? Show your work.

It saves one massive from the cars and one massive from unplugging chargers. One massive plus one massive equals a total reduction of two massives.

aoner2• 8 years ago

Cement is one of the bigger unknown problems in the world regarding climate change. I think we can make a huge improvement by creating carbon negative concrete. There are couple of different ways to create carbon negative concrete, but they keep on failing due to the industry and barriers. There is a great insightful article with an in depth analysis into why these techniques/companies fail: https://www.sciencedirect.com/science/article/pii/S221042241...

I think in the future we should create buildings that heal and store carbon instead of pollute tons of carbon dioxide. Magnesium based cements can have huge impact: https://pubs.acs.org/doi/abs/10.1021/acs.chemrev.5b00463

However,I don't see the cement industry changing anytime soon, so I expect innovation in the industry to come from less impactful angles (like http://c8s.co.uk/ and http://www.blueplanet-ltd.com/ ).

If anyone has other insights I'm really curious.

Pxtl• 8 years ago

The turbine will produce about three megawatts of energy on average which, when working at full capacity, is enough to power 2,400 U.S. homes for one month.

Seriously, how does this kind of basic unit bungling happen in every report that involves Watts?

jacquesm• 8 years ago

I spent a couple of years on a forum with renewable energy enthusiasts. In spite of endless corrections even there the posters kept messing that up so I have absolutely no confidence in journalism ever getting this right.

rdiddly2• 8 years ago

Unfortunately that's not the only blunder in that sentence. Are we talking "on average" or are we talking "at full capacity?"

Not to mention the stylistic blunder by which a mathematical average, or a bunch of energy (or hey possibly even a turbine), is said to be "working at full capacity." I guess this is a dangling clause? Not sure if that's the right term for it.

Shave off all the fur and you're left with a pretty good sentence:

The turbine will produce about three megawatts of energy on average, which is enough to power 2,400 U.S. homes. (Assuming that figure is right.)

It's shorter too.

rdiddly2• 8 years ago

Speaking of this kind of skepticism, 57 truckloads of concrete for one wind turbine seemed like an awful lot, so I did some rough math. Turns out 57 truckloads is probably right. Jesus. I assumed a pad-and-pedestal foundation where the pad is a cylinder 60'|18.3m dia. and 4'|1.2m thick, and the pedestal is also a cylinder but 20'|6m dia. and 4'|1.2m high. Total volume of both is about 465 yd³|355m³. Since the typical truck holds about 8 yd³|6m³, that's about 58 truckloads, which is surprisingly close to the 57 they stated.

Each wind farm has a substation too, which will use some quantity of concrete for equipment pads. And some wind farms built in remote areas have to have their own transmission infrastructure built -- towers, with their own foundations, and switching substations, with again more equipment foundations. You could say concrete is the foundation of our economy... chortle chortle... groan...

EDIT: added SI units for our rest-of-the-world pals

ScottBurson• 8 years ago

Almost right: the turbine will produce about three megawatts of power. The confusion between power and energy is precisely the problem.

pcmaffey• 8 years ago

Hempcrete could replace a lot of non-load bearing applications. For anyone interested: https://en.wikipedia.org/wiki/Hempcrete

djrogers• 8 years ago

There are tons of alternatives for non load bearing applications, that’s not really the problem.

Lazare• 8 years ago

I found the article odd, because it talked a lot about the different dynamics and the emissions of different things, but never netted them out.

If you're going to talk about the CO2 emissions of the concrete needed for a wind turbine, the obvious next step would be to net them all out and figure out if building wind turbines is a net reduction in CO2 or not.

The author seemed to go out of their way to imply that as long as we use Portland cement, it would not be a net reduction, but they never actually came out and said that.

Not quite sure what to make of it. It's like reading an article that talks about electric cars and how high electricity can make them more expensive than you think, but then...never actually calculates their operating cost and compares it to a conventional ICE powertrain.

dmurray• 8 years ago

Cement is the second-most consumed material in the world, after water.

This is repeated in the article but it doesn't sound right to me. Concrete is mostly stone and sand, with cement only making up 10-20% of the mixture. So both of those should be consumed more than cement is.

kleim• 8 years ago

Interesting fact: there is actually a global sand shortage (https://www.independent.co.uk/news/long_reads/sand-shortage-...)

fouc• 8 years ago

https://en.wikipedia.org/wiki/Environmental_impact_of_concre...

Looks like it is the production of concrete materials that are generating CO2.

scalablenotions• 8 years ago

Let's see. Can you move your feet?

Are we stuck with cement?

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