
Are we stuck with cement? - sus_007
https://theoutline.com/post/5124/are-we-stuck-with-cement-environmental-impact
======
philipkglass
_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...](https://s3.amazonaws.com/academia.edu.documents/39977040/1-s2.0-S0959652612006129-main.pdf?AWSAccessKeyId=AKIAIWOWYYGZ2Y53UL3A&Expires=1530469511&Signature=iO7NNWFleA6%2F%2F8NF2ta4wIRigTA%3D&response-
content-
disposition=inline%3B%20filename%3DGlobal_strategies_and_potentials_to_curb.pdf)

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.

~~~
quotemstr
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.

~~~
philipkglass
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.

~~~
SerLava
That's a huge part of it. I do feel that the aforementioned anti-industrial
mindset does still motivate the lack of enthusiasm for number crunching.

Find me a way to reduce co2 that involves wicker, green leaves, and pure
water, even tangentially, and you'll find huge support for it even if it can
be beaten by donating three dollars to a wind farm. That notion will affect a
lot of people who aren't even consciously anti-industrial. It's just kind of
the default frame of mind when discussing environmental protection.

Or try talking about fixing global warming instead of preventing it. People
who are (rightly) very concerned about _impending wholesale death_ suddenly
are not interested at all. It comes as an affront. Our mental image of a
global warming solution is already clearly set as some type of industrial
shutdown.

------
madaxe_again
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/](http://ecolime.co.uk/c02-quick-facts/)

~~~
NeedMoreTea
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.

~~~
coryrc
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.

~~~
NeedMoreTea
I don't know enough of the details but there were reports about using it for
the Swansea lagoon barrier - a £1bn tidal energy project that was to be about
6 miles long. The government blocked the project just last week so we'll never
know.

~~~
bainsfather
"The government blocked the project just last week so we'll never know."

To be more accurate - the government decided not to subsidise the project. It
was emphatically the right decision - the economics of it were awful compared
to wind, solar.

~~~
NeedMoreTea
To be even more accurate the government decided to ignore the clear advice of
the independent cross-party committee of MPs they appointed, and after the
announcement chairman of said committee said the government were not even
comparing like with like in their economic comparison.

Makes it look solely a political not economic or environmental decision.

------
Pxtl
> 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?

~~~
rdiddly
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.

~~~
rdiddly
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

~~~
EADGBE
I never try to get too much into the math, but the amount of concrete required
for X is staggering in general, even at small scale.

Recently built a foundation for my deck, what was estimated on the concrete
tube for pillars was nowhere near what was actually needed.

------
ramchip
> 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.

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

~~~
konschubert
>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

~~~
Koshkin
You are right! Silly me.

------
Lazare
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.

------
mabbo
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
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?

------
dmurray
> 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
Interesting fact: there is actually a global sand shortage
([https://www.independent.co.uk/news/long_reads/sand-
shortage-...](https://www.independent.co.uk/news/long_reads/sand-shortage-
world-how-deal-solve-issue-raw-materials-supplies-glass-electronics-
concrete-a8093721.html))

------
realandreskytt
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?

~~~
dzhiurgis
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?

~~~
HeyLaughingBoy
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.

------
sandworm101
>>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
Centuries? Doesn't the material lose much of its strength when the rebar rusts
away, which it certainly does in a century?

~~~
mchannon
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.

------
adrianN
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.

~~~
amluto
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
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.

------
crankylinuxuser
> “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.

------
lpcam33
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.

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

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

~~~
BaesRule
We see lower birth rates when countries grow richer. People have a lot more
kids when there's a high chance a lot of their kids won't live long enough to
support their parents in old age. Also in richer countries people aren't
relying on their kids to support them in old age as much as in poorer
countries.

~~~
quotemstr
No, FooHentai is right. We're screwed, Malthus-style, in the long run no
matter what we do. The problem is that while modernism does tend to moderate
fertility, it doesn't do so across the board. Some subgroups nevertheless have
fertility far above replacement, and the exponential growth function tells us
that these high-fertility groups will come to dominate the population.

In other words, selection pressure ---biological, cultural, doesn't matter ---
always wins in the end. Mother nature has the last laugh.

~~~
guntars
Oh, please mention some of these subgroups by name.

~~~
quotemstr
The point I'm making is independent of whatever trap you're trying to set ---
the specific groups don't matter. As long as _some_ group has high fertility
and is able to pass on this high fertility to future generations, the dynamic
I'm describing applies.

~~~
guntars
Your reasoning just reminded me of that of some confused individuals that see
everything in purely biological terms. Fertility alone isn’t some silver
bullet for the success of a population, even for bacteria and ever more so for
people. Why isn’t there already a dominant Uber-fertile group?

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

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

------
fouc
[https://en.wikipedia.org/wiki/Environmental_impact_of_concre...](https://en.wikipedia.org/wiki/Environmental_impact_of_concrete)

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

------
scalablenotions
Let's see. Can you move your feet?

------
timwaagh
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.

~~~
aoner
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...](https://www.sciencedirect.com/science/article/pii/S2210422415300228)

 _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._

~~~
timwaagh
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.

