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Our Future Is (Literally) Crumbling Before Our Eyes

Our reinforced concrete infrastructure sends a dire warning
Wednesday, July 6, 2016, 12:10 AM

The sorts of predicaments the world faces -- ranging from over $200 trillion in debt, to our unsustainable addiction to fossil fuels, to our over-stressed ecosystems -- all require that we get deadly serious about confronting them ASAP, and make difficult decisions and trade-offs.

However, our global leaders always seem to opt to kick the can down the road if at all possible. Short-term thinking and near-term priorities dependably get precedence over doing the right thing for the future. Tomorrow’s generations are thrown under the bus by selfishly motivated actors today.

As I’ve put forth over and over again: we’re simply not going to make it unless we get much more serious about our efforts than we have been to date. Yes, it’s a wonderful thing that Elon Musk is building sexy electric cars; but even a single minute spent with a pencil, paper and the aggregate energy statistics on transportation will reveal that there’s an enormous gap between where we currently are and where we need to be.

Most will never spend that minute; which is why I continue to do what I do.

For example, many people wave their arms lazily at the statistics for wind-generated electricity and never bother to ask if its current growth rates can be sustained. Or wonder just how tremendously massive the scale of the effort will need to be to meet any realistic sustainability goals.

In a prior companion piece to this article, I quoted a study which determined that to simply meet the wind power goal put forth in the recent Paris accord, the world would have to massively upshift from installing 37 wind towers per day currently to more than 1,300 per day by 2028.

Can we do that? Maybe. But not without a maniacal commitment to making it happen. And that’s the thing: the world is instead hoping that somehow ‘the market’ will deliver sufficient wind power in time. Given the state of the global financial system -- with its more than $200 trillion(!) in debt -- is that really something we want to leave to hope?

But leaving the economic and political issues of that challenge aside, I’d like us to focus on the more practical issues of the energy investment required to build out a new energy infrastructure, not to mention the longevity and durability of the components we'd be installing.

I’ve always found this time-lapse video of a single wind tower installation mesmerizing. The skill on display is amazing: 


Here’s a brief summary for those of you too busy to watch this construction process right now: Diesel, diesel, diesel, reinforced concrete, diesel, petroleum, diesel.  That is, installing a wind tower like this requires a huge amount of fossil fuels to accomplish. 

To focus in further, watch from the 45-second mark to one minute.  What you’ll see there is 96,000 pounds of reinforcing steel, and 53 cement trucks used to pour the windmill's base.

Which brings us to an overlooked and very important part of the story: reinforced concrete. If the pyramids are a lasting testimony to the durability and long-term thinking of the ancient Egyptians, then reinforced concrete will be modern society’s opposite statement. A legacy of short-term thinking and a disposable mindset.

This article does a wonderful job of laying out what I mean:

The problem with reinforced concrete

June 17, 2016

By itself, concrete is a very durable construction material. The magnificent Pantheon in Rome, the world’s largest unreinforced concrete dome, is in excellent condition after nearly 1,900 years.

And yet many concrete structures from last century – bridges, highways and buildings – are crumbling. Many concrete structures built this century will be obsolete before its end.

Given the survival of ancient structures, this may seem curious. The critical difference is the modern use of steel reinforcement, known as rebar, concealed within the concrete. Steel is made mainly of iron, and one of iron’s unalterable properties is that it rusts. This ruins the durability of concrete structures in ways that are difficult to detect and costly to repair.

While repair may be justified to preserve the architectural legacy of iconic 20th-century buildings, such as those designed by reinforced concrete users like Frank Lloyd Wright, it is questionable whether this will be affordable or desirable for the vast majority of structures. The writer Robert Courland, in his book Concrete Planet, estimates that repair and rebuilding costs of concrete infrastructure, just in the United States, will be in the trillions of dollars – to be paid by future generations.

Steel reinforcement was a dramatic innovation of the 19th century. The steel bars add strength, allowing the creation of long, cantilevered structures and thinner, less-supported slabs. It speeds up construction times, because less concrete is required to pour such slabs.

These qualities, pushed by assertive and sometimes duplicitous promotion by the concrete industry in the early 20th century, led to its massive popularity.

Reinforced concrete competes against more durable building technologies, like steel frame or traditional bricks and mortar. Around the world, it has replaced environmentally sensitive, low-carbon options like mud brick and rammed earth – historical practices that may also be more durable.

Early 20th-century engineers thought reinforced concrete structures would last a very long time – perhaps 1,000 years. In reality, their life span is more like 50-100 years, and sometimes less.

Building codes and policies generally require buildings to survive for several decades, but deterioration can begin in as little as 10 years.

(Source)

The main issue is simple: putting in steel reinforcing bars lowers the cost and weight of installing reinforced concrete, but at the severe expense of reducing the lifespan of that concrete -- from millennia to perhaps a hundred years, and sometimes far less.

Steel corrodes (rusts). When it does, it expands and leads to something you’ve seen but perhaps not recognized: concrete cancer.

(Source)

In every single reinforced concrete structure, silently behind the smooth exterior, the concrete is breaking itself apart due to the corroding steel inside.

Dust To Dust

What all this means is that literally everything you see today that’s made of concrete will need to be replaced within a hundred years of its installation.  Every bridge, every building, every roadway…all of them.

They’re just rotting away from the inside, silently and relentlessly.  When the rot progresses far enough, it leads to something called ‘spalling’, which is when the surface of the concrete crumbles away to reveal the rusted steel beneath.

Once you notice this, you’ll see it everywhere: 

Of course, it’s true that anything you build will erode over time and require maintenance and care to provide longevity. The problem with reinforced concrete is that it’s extremely difficult to remedy once it’s poured because the affected parts are inside and hard to access.

So it’s nearly universally true that everything poured from concrete over the past century, as well as most of what is still being poured today, is fated to have a very short, very disposable lifespan.

Why This Matters

So let’s travel forward just a few short years into the future. There we find hundreds of trillions of dollars more of global debt, even greater sums of unfunded liabilities, much more expensive fossil fuels (as explained in this recent podcast with Art Berman) -- all competing with a crumbling concrete-built environment that will have to be torn down and replaced.

Where the article above concludes that trillions of dollars will need to be be spent just in the US alone to replace its concrete infrastructure, that number will be at least an order of magnitude higher for the entire globe.

And we don’t get much incremental benefit for the cost of replacing a crumbing piece of infrastructure. When you tear down a bridge and replace it you still have one bridge performing the services of one bridge. Sure, you occupy a number of people in the construction and manufacturing trades for a while, but you don’t get any added value beyond that. It’s not the same as putting in a new bridge at a new location to open up a new geographic area for greater economic activity.

You just get your bridge replaced.  One for one: an economically neutral exchange that costs a lot of money.

My larger question here is this: Can all the competing future demands even allow all of the current concrete infrastructure to simply be replaced, let alone expanded?

What if there’s not enough energy for that task, plus the demands of feeding and sheltering and defending ourselves?

It's my strong belief that we’ll regret the short-term mentality that led us to trade durability for lower cost. Furthermore, I contend that competing future demands will prevent us from replacing all of our decaying infrastructure with similar copies.

Either they won’t be replaced at all because we cannot afford to do so (see: Detroit) or we'll have to bite the bullet and begin installing truly durable structures that won’t simply tear themselves apart from the inside in a few short decades. Which will likely be a lot more expensive to build.

Conclusion

Hopefully I’ve opened your eyes to the folly of building our society atop a foundation with an expiration date.

Reinforced concrete structures are crumbling all around us, something that's immediately obvious once you begin to look for it for yourself. In most cases, it isn't poor construction practices that are to blame, but simple chemistry and the decision to use steel as a reinforcing agent. The very best construction company in the world will still see their efforts end in ‘concrete cancer’ sooner or later.

There are some newer ways of slowing or mitigating this effect, but those aren't always used. In my observation, more often than not they're simply not deployed.  Steel is laid down, usually with rust already showing upon it, and then the concrete is poured over it. And that’s that.

This disposable mindset is rooted in the false assumption that we’ll always have abundant surplus energy to use. Wasteful practices are not a problem if you always have access to abundant surplus energy. Otherwise, as in the case we're finding ourselves in, they bring tragedy.

Perhaps that tragedy will be many years in the future. But its inevitability is assured.

If we were thinking about all of this clearly, we’d not be pouring wind tower bases using reinforced concrete. Instead, we'd build pads that would be durable for centuries, because presumably we’re investing in wind power for the very, very long haul.

In the end, isn’t there something terribly ironic about making a future-betting ‘investment’ in wind upon a base of reinforced concrete that is, by definition, destined for a short, disposable life?

That alone says much about just how un-serious we really are. And how out of integrity our actions are with the very premise of sustainability.

~ Chris Martenson

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44 Comments

Bobby's picture
Bobby
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Posts: 19
The Banking & Financial foundation too is crumbling!

Good article, this! Its coming full circle - everything around us has, in some form or the other, become redundant and seems to be crumbling. I wish there were scientific mathematically backed solutions/formulae for fixing the banking and financial sectors. New ways are also around the corner but the transition phase is going to make life tough for a whole generation.

Arthur Robey's picture
Arthur Robey
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Posts: 3936
Bureaucratic inertia.

The creative juices have been surging through the body recently. It is very hard to resist the temptation to build  even knowing that a permanent dwelling will attract a penalty in rates and taxes.

But how to convince the petit Bureaucrats at the council chambers that a reinforced concrete raft slab is not the only way to go? They have so little exposure to any alternative constriction methods. 

It is obvious to me that I should build with massive Pisé walls. (Ramed earth.)

The art of the bureaucrat is to make the possible impossible. 

 

LesPhelps's picture
LesPhelps
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Denial; The Wind Energy Industry

At one level, I could wish to unknown how short the lifespan of reinforced concrete is.

I travel mostly by car these days.  Having a metal knee, flying requires me to submit to unreasonably invasive search procedures by the TSA.  While the search procedures themselves are perhaps not unacceptable to me, what it says about my true "freedom" I find unacceptable.  I despise the "Patriot Act" with every breath I take.  "Land of the Free?"  If you believe that, I've got a steel reinforced concrete bridge I'd like to sell you.

Anyway, I travel mostly by car these days.  If I travel any direction but North from where I live, I get to see vast complexes of wind turbines and we are only getting started.  I have to say that a few of them are not all that offensive to look at.  However, the number in place has already exceeded the "esthetic barrier."  They have already become an eyesore overall and, as I said, we are barely getting started.

 

cmartenson's picture
cmartenson
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It's everywhere...

In the next town over (Greenfield MA) they recently put in a new high school.  The hue and cry from the parents and teachers was that it was long past time for a new building.

After all, the 'old' one was built in late 1960's!!

Everyone just accepted that as a perfectly good argument and moved on.

As far as I know, nobody ever mentioned that a building with a 40-50 year life span (essentially a disposable building) was unacceptable.  Nobody proposed spending even more on this go round to build something that would last longer.  Everyone is accepting of the fact that 'buildings just fall apart' and need to be regularly replaced.

Nobody has traveled to Europe, apparently, and seen buildings from the 1200's still in daily use.

At $66 million dollars I would have wanted to see a new high school go in that would last until the year 2816.  Virtually nobody else thinks like that at the moment.

The extraordinary mistake being made here is the squandering of current available energy and resources to build things that will need to be replaced in 2066.  Life will be very different then, and it's a pretty solid bet that energy resources will be vastly more expensive and difficult to come by.

I remain confused as to why this is such a hard concept to get across.

Here's a partial list of things that will be in competition with that eventually decrepit high school for attention:

Mark Cochrane's picture
Mark Cochrane
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The nature of growth....

Chris provides a very prescient outlining of the future we face as our infrastructure and buildings crumble to dust. I submit that this is as much an outcome of our perverse economic models as our shortsightedness, as we always put short term profits in front of long term sustainability.

Assuming an anemic 1.4% growth rate for the next 50 years would mean that we should have to double the infrastructure buildout, reinforced concrete use in this case, during that time. This is the all too familiar exponential growth function. We will have to use more concrete in the next 50 years than we have used in all of time beforehand. That in itself is problematic given all of the energy, capital and resource issues that we face but at least it holds the possibility of a true economic return on investment.

However, as laid out by Chris, we will have to replace all of existing structures during the next 50 years (or less) because it is rapidly decaying around us. That means, to truly have the expected ´growth´ in our infrastructure we will need to build twice as much of it as would be anticipated for that 1.4% annual expansion to happen. In other words we would need to build pour twice as much reinforced concrete in the next 50 years as has been in history to date. Can we do that? If not, the true growth is going to suffer even as we pour more and more concrete.

The perversion is that our gold standard GDP metrics cannot tell the difference between building new infrastructure and replacing decaying roads, bridges and buildings. Any idiot can see the difference in benefit between having two bridges and paying for the same one twice but our economic metrics can´t. It is just consumption and more is better.

This is the physical manifestation of declining returns on investments. The Romans used to invest in a new road or bridge and voila, they had ´more´ infrastructure to add to their empire and growing economy. Heck, their roads are still in use today! They paid more per mile up front but once in place they effectively had permanent infrastructure. We have done things on the cheap and now have to pay twice as much to build a new mile of road or just as much every year to maintain the roads we have. This is great job/profit security for a few industries but a catastrophic miscalculation for a nation. Making matters worse is that we have not been doing the upkeep on the infrastructure we have for decades so we are going to be increasingly hard put just to maintain what we have in place. There will be precious little left for ´new´ expansion.

 

 

LesPhelps's picture
LesPhelps
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Mark Cochrane wrote: The
Mark Cochrane wrote:

The perversion is that our gold standard GDP metrics cannot tell the difference between building new infrastructure and replacing decaying roads, bridges and buildings. Any idiot can see the difference in benefit between having two bridges and paying for the same one twice but our economic metrics can´t. It is just consumption and more is better.

Ok, that's enough reality for one morning, at least before I'm fully caffeinated.  I believe I'll close this browser down and digitally kill a few aliens for a while.

blackeagle's picture
blackeagle
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13rd century comparison

Chris,

I don't think the comparison you make between the 13rd century and now is accurate.

Back then, the issue of money was as acute as it is today (May be more since they did not invent money printing at the time). So, the decision based on cost was as true as it is today. The few building techniques options that were available at the time were almost binary: good vs. no good. It happens that the good was really good, and the bad really bad. Today, thanks to technology, we have much more options. Ranging from the really good to the really bad and an infinity of qualities in between.

Back then they choose the best comprimise between quality and cost (I can't imagine a king not considering cost for a cathedral that could bust its state budget). Exactly what we do today. The difference is that today the crossing point between good enough and cost is much lower than in the 13rd century (or another time).

Their good job was very lengthy to complete. Just see how long it took to build one cathedral: 100 years? 150 years? 200 years?

In conclusion, it is hard to compare these two times because of very different conditions even if decision making was following the same logic. Today we have more options to lower cost and get good enough quality for those who decide (50 years is usually longer than their professional life expectancy).

Otherwise, I agree with the article. When I was in Paris I lived in a building built in the 1700s (Flagged as an historical building). It isn't a fancy building. With good maintenance, it is still standing today, in good shape (no bowing walls, perfect staircase, etc...) and relatively comfortable (Insulation is not at its best) regarding Parisian winters and summers

                 

One more point: Here in Quebec they use green-painted rebar for highways. I guess this is a coating designed to prevent (or delay) rust. No idea for how long... Concrete highways last longer than asphalt.

60 years ago, the Champlain bridge (Crossing the St-Lawrence river in Montreal) cost 60 millions CAD. It is now at end of life mostly for its concrete part. The new one will cost between 3.5B and 5B thanks to inflation, corruption, heavier processes and regulations. Will it last 10 times longer? (I take in account doubling cost very 20 years). US is certainly facing the same increase in cost.

Regards

JM

ckessel's picture
ckessel
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The green rebar

Hi JM,

The green on the rebar is an epoxy coating intended to prevent rust. It adds some cost and unless perfectly installed without nicks and so on, will also break down. When the bar is cut, the ends are seldom covered either.

Additionally, building codes are now such that it is very difficult to use concrete without rebar in that you would need to make your concrete design so that all elements of the concrete were always in compression. The steel is intended to resist the tensile forces within a structure.

Coop

DRS78750's picture
DRS78750
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Basalt Rebar

It is not like the technology is not available. See www.basalt-rebar.com 

No worries about nicks, uncoated ends; higher tensile strength and stronger than steel, same coefficient of expansion as concrete, no rust, etc.  

blackeagle's picture
blackeagle
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Epoxy

Hi Coop,

Thanks for the details.

In conclusion, since these prefabricated rebars are transported by truck in piles (shake, shake, shake), then dragged all over the construction site (scratch, scratch, scratch) before their final place (aahhh, finally...), the coating could be so damaged that its real protection is not what's expected. On top of that considering the immense temperature swings between winter and summer (In Quebec, of course), the epoxy will eventually unstick from the steel and the concrete (different thermal expansions for different materials), unless it is not too hard and brittle.

Well, not perfect, but may be still better than just plain steel.

This pdf shows a different alternative. On the long run we will see which one is better.

 

davefairtex's picture
davefairtex
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set in concrete

Hmm.  I guess those accountants aren't so stupid after all.  Here I was, imagining that depreciating the structure over 27.5 years was a big scam that just enabled me to take a big, fat, undeserved deduction every year.  What could go wrong with concrete?  Now come to find out...that depreciated structure may very well need a complete rebuild after 40-50 years.  Holy crap.

Sigh.  Just once, I'd like things to be actually better than we expected them to be.

Maybe I'll go back and look at gold prices.

There.  That makes me feel better.

 

aggrivated's picture
aggrivated
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first come first served-what's a best use for fossil fuels left?

I have a friend from Germany who bemoans the look of 200+ year old houses with solar panels--whole towns worth, not just a few here and there and then every hill top seeing one of the spinning bird snatchers to generate more electricity..  If 'x' amount of diesel is used to build Germany's 25 year life span infrastructure and the USA is mainly building new bridges and schools to use our share of currently cheap diesel, then who is going to have cheap electricity to power their 'old' school in 20 years?  Gail Tverberg jumps into the middle of this dilemma with her excellent article on the Physics of Energy and the Economy https://ourfiniteworld.com/2016/02/08/the-physics-of-energy-and-the-economy/

Bottom line, the economy is energy flows.

So what is the best way to 'spend' our stored sunlight (diesel)?  More schools and bridges to maintain in a world that won't be needing them so much in 25 years, or a shot in the arm for our electrical generation for 25 years, or how about a third option not on most people's radar--build a building with human and animal energy that will last for 500 years.  Anybody out there willing to run the EROEI on the above energy investments?  It's too many apples and oranges for my calculator, but in the broad sweep of the three I would want to land somewhere between #2 and #3 options, not #1. 

I, however, don't speak German and with family connections here in the USA will plan to ride out the malinvestments and the consequent unecessary hardships, AND hopefully being able to prepare the others I love to be resilient enough to ride the roller coaster down and not jump off too soon in the descent.

On a more practical note, I daily drive my Prius down an alley that is poorly maintained (at 5 mph) and wonder how long I could drive this 'green' car on poorly maintained highways.  I'm thinking that the next vehicle will need to be more offroad--like a mountain bike!

Michael_Rudmin's picture
Michael_Rudmin
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Looking at the pictures...

it looks to me like pictures 1 and 9 are identical; they are splice girder bridges on artistic piers perhaps?

Picture 6 is a segmental bridge. I'm thinking maybe that one is a Figg Engineering project.

Picture 3 looks like it might be a double-tee concrete parking deck on a steel frame.

The last picture looks like it is possibly a precast hollow core apartment project.

A lot of these may last longer than 100 years. Some may only last 30. A lot of factors determine how fast they will wear out. If a high-chromium steel is used in the bridge -- Virginia, for example, has shifted to entirely MMFX -- the bridge well may be much slower to degrade. Sometimes the steel is stainless, as for some Navy projects, but that is only good in oxidizing environments. Stainles can corrode away in months in an anoxic saline environment.

Other factors also come into play: the chloride content of the grout has a lot to do with the rate of rusting. The alkaline pH can cause faster rusting. If I remember correctly, the American Concrete Institute has a yard full of samples of various mix designs, specifically to determine what decays and what doesn't. Armed with that knowledge, bridges can and do get constructed to last longer. Prestressing the bridge (such as is done for the splice girders or double-tees) and post-tensioning the bridge (as for the segmentl AND the splice girder) can increase the lifespan. The prestressing will last longer; the bost-tensioning can be replaced without replacing the whole bridge.

Likewise, the exposure to elements helps determine longevity. If a building structure is protected from the elements, it is unlikely to decay as fast as an exposed bridge.

So by now, most bridges (and I would expect, buildings) come with a design life. Thus, the states can sculpt their budget layout, to make sure that costs don't hit it all at once.

KugsCheese's picture
KugsCheese
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Failing Rebar

Just another example of modern day stimulus programs.  They work so well since early 1990's.

Arthur Robey's picture
Arthur Robey
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A winner

Interesting basalt rebar DRS. 

If we combine that with bio-cement and 3D printing we will have cheap, long lasting buildings. 

https://en.m.wikipedia.org/wiki/Sporosarcina_pasteurii

And then we could use genetic engineering to create Monster bamboo and live in that. The next house could be growing from seed right outside. . Natural phosphorescent walls with parasitic fruits growing inside.

That really would save on housework, cooking, shopping and farming.

Barring the giggles. 

Incredulity is not an argument. 

 

yagasjai's picture
yagasjai
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Insulated Concrete Block Construction?

I am wondering if the same concerns hold true for residential home construction with Insulated Concrete Forms? Is more care taken with the steel reinforcement when involved in residential construction? I have heard this method of building touted as a very durable and long-lasting way of building, so I am wondering how it compares with commercial construction.

ckessel's picture
ckessel
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Hi Yagasjai, I have been

Hi Yagasjai,

I have been designing and constructing ICF buildings since 2003 and have about 35 structures completed. Most are solar homes with radiant heating placed in a raised concrete pan deck floor system. The under floor space (sometimes called a crawl space) is used for cooling.

I have often stated that I think the lifespan of a home constructed in this fashion would be about 1000 years assuming that the roof is maintained. My personal (belief) is that structural concrete placed within an insulated covering and sheltered from direct contact by water (such as a bridge) will last a very long time. I often have used the Pantheon as an example of the longest continually occupied structure in the world. (I am sure there are others less well known)

But a significant issue is whether the concrete is designed in compression only (such as the Pantheon) or whether it is being used in tension as well. Modern design procedures and building codes all assume that the concrete is being used to resolve compression and tension loads.

Concrete is great in compression and lousy in tension. Steel is the reverse. Combining them allows for a lot of creativity in their use. The risk is described by Chris in his article and the big take away is the difficulty in making repairs which is usually called demolition.

Many bridges could be designed as concrete arch structures which are in compression. They look very nice and are more expensive to construct ....... and will last much longer. They can also be made of stone such as the Romans engineered.

Michael_Rudmin's picture
Michael_Rudmin
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So where are you based, ckessel?

I have long been considering ICF, more specifically the USS-Panel.com system. My feeling about it is that a foam-surrounded concrete house is still subject to every kind of attack, whereas a foam-centered system may last longer.

The shotcrete system also seems reasonable to me for application... but maybe I'm wrong; maybe it's weaker or more pervious. Do you have any opinion on that?

What kind of system do you prefer?

And in what part of the country do you operate? I'm in the Hampton Roads Va area.

My one other takeaway is that I think I may have a way to embed prestressed concrete in the whole system, or maybe even make a 3-dimensionally pretressed; I've tried it out once, partially failing and partially succeeding. I think I know what to do to completely succeed.

Arthur Robey's picture
Arthur Robey
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Embodied energy of Steel.

A good intuitive feel for the energy used to make steel can be seen here.

ckessel's picture
ckessel
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Hi Michael, I live in the

Hi Michael,

I live in the Sierra Nevada Mts. of central California. I have been using the Quadlock ICF product for a number of years which is a panelized system rather than a prefabricated 'block'. It provides insulation on both surfaces and the concrete core can vary from 4" to 24" in width depending upon the application.

The most durable structures in this area were constructed of stone masonry and date back to the gold rush era. That is pretty recent compared to buildings around the world but I think masonry has proven itself as regards durability and longevity.  Keeping a roof on the structure is the key and that will always require regular maintenance it seems.

My current thoughts have migrated to the living roof concept for long term low maintenance functionality. But there are issues with that as well. I guess if you are expecting a free lunch you may end up hungry!!

Cornelius999's picture
Cornelius999
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Great article Chris, the best

Great article Chris, the best metaphor and reality of our insubstantial age, my eyes are contemplating the long pathways of rebar of our new light rail system as I walk home through Dublin. They only closed the last of the old tram lines in the 1960's.

I watched a documentary recently on space-archaeology where a specialist was still able to identify the buried walls of a turf-built, Viking age building, maybe in the Shetland Islands, from a satellite 300 miles above the earth. 

Bankers Slave's picture
Bankers Slave
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Hempcrete.

jtwalsh's picture
jtwalsh
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Not just large infrastructure

Yagasjai's question about residential construction triggered my memory about several articles I have seen in the past few months concerning traditional, poured concrete foundations in Connecticut residences. 

Apparently, a concrete company which poured thousands of foundations over the years was using a type of rock in the aggregate which leaches a chemical that prematurely causes the concrete to weaken and ultimately collapse.  Insurance companies have taken the position that this is not a condition covered by homeowner's policies. At least one court case has held that a homeowner's discovery of the condition came after the statute of limitations had run. No recovery could be made against the contractor who built the house. If I remember correctly, the concrete company is out of business so there is no recovery from them.

The result is a number of home owners with collapsing foundations, some to the point of the property being condemned, with no alternative but to replace the foundation in its entirely.  Unfortunately the present cost for doing so can be more that the value of the property.

Going forward the infrastructure issues will not be just with public structures.  I fear much of the residential housing built in the last "boom" times will not hold up over the long hall.

Friends and family thought we were crazy when we bought our now one hundred eighteen year old house.  My stone foundation has not crumbled. The four by six, post and beam, frame has not sagged. The trees harvested to build the structure are now housing the fifth generation of inhabitants. We did make substantial improvements to plumbing, heating, insulation and electric, resulting in a house that will stand the test of time but has all the modern bells and whistles.     

http://www.nbcconnecticut.com/troubleshooters/Crumbling-Foundations-Hundreds-of-Homeowners-Pack-Foundation-Meeting-352733321.html

JT

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It's not just concrete

Many railroad bridges in my area (Eastern New York), even on heavily used lines have remained unpainted for years.  They are slowly rusting away even as heavy rail traffic (perhaps 5-10 thousand rail cars a day on a double track line near me) passes over.  This is also true of several active rail bridges over the Hudson River. Well constructed steel bridges will not last if not painted. 

Over the weekend, I was able to take a close look at the rail bridge over the mouth of the West River in Brattleboro, VT from a kayak.  It had been so long since the unpainted, but still used (by Amtrak and freight) bridge had been even cleaned that several 4-5 foot tall trees were growing out of the debris that had accumulated on the girders below the rail bed at the sides of the bridge.  The two well constructed old stone and mortar piers that supported the bridge had once held a double track, but there has been only one at least since I lived in Brattleboro from 2001-2006.

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Basalt rebar looks fantastic
DRS78750 wrote:

It is not like the technology is not available. See www.basalt-rebar.com 

No worries about nicks, uncoated ends; higher tensile strength and stronger than steel, same coefficient of expansion as concrete, no rust, etc.  

That's simply amazing...I just read all the specs on it...only thing I couldn't find easily was the price comparison to steel.

But even if it's 2x or 3x, I'd bet that over the long horizon that it's a steal.

 

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More on basalt.

But even if it's 2x or 3x, I'd bet that over the long horizon that it's a steal.

 

Much cheaper.  And the material is abundant. 

There is a lot about it on youtube.

It seems like a good candidate for building an airship. (It also comes as thread.)

http://smarter-building-systems.com/smarter-building-basalt-faqs/

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jtwalsh wrote: Yagasjai's
jtwalsh wrote:

Yagasjai's question about residential construction triggered my memory about several articles I have seen in the past few months concerning traditional, poured concrete foundations in Connecticut residences. 

Apparently, a concrete company which poured thousands of foundations over the years was using a type of rock in the aggregate which leaches a chemical that prematurely causes the concrete to weaken and ultimately collapse.  Insurance companies have taken the position that this is not a condition covered by homeowner's policies. At least one court case has held that a homeowner's discovery of the condition came after the statute of limitations had run. No recovery could be made against the contractor who built the house. If I remember correctly, the concrete company is out of business so there is no recovery from them.

The result is a number of home owners with collapsing foundations, some to the point of the property being condemned, with no alternative but to replace the foundation in its entirely.  Unfortunately the present cost for doing so can be more that the value of the property.

Going forward the infrastructure issues will not be just with public structures.  I fear much of the residential housing built in the last "boom" times will not hold up over the long hall.

Friends and family thought we were crazy when we bought our now one hundred eighteen year old house.  My stone foundation has not crumbled. The four by six, post and beam, frame has not sagged. The trees harvested to build the structure are now housing the fifth generation of inhabitants. We did make substantial improvements to plumbing, heating, insulation and electric, resulting in a house that will stand the test of time but has all the modern bells and whistles.     

http://www.nbcconnecticut.com/troubleshooters/Crumbling-Foundations-Hundreds-of-Homeowners-Pack-Foundation-Meeting-352733321.html

JT

The concrete and road building industries are big scams.   New form of Stimulus!

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Quercus bicolor wrote: Many
Quercus bicolor wrote:

Many railroad bridges in my area (Eastern New York), even on heavily used lines have remained unpainted for years.  They are slowly rusting away even as heavy rail traffic (perhaps 5-10 thousand rail cars a day on a double track line near me) passes over.  This is also true of several active rail bridges over the Hudson River. Well constructed steel bridges will not last if not painted. 

Over the weekend, I was able to take a close look at the rail bridge over the mouth of the West River in Brattleboro, VT from a kayak.  It had been so long since the unpainted, but still used (by Amtrak and freight) bridge had been even cleaned that several 4-5 foot tall trees were growing out of the debris that had accumulated on the girders below the rail bed at the sides of the bridge.  The two well constructed old stone and mortar piers that supported the bridge had once held a double track, but there has been only one at least since I lived in Brattleboro from 2001-2006.

And then there is the widespread use of primer-less paint on the outside with no sanding.  More Stimulus!

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Aliens

Hmmmm. Maybe the aliens who built in stone knew a thing or two.

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Thank You, cKessel.

It's good to hear what you have to say on that matter. Please watch out #or quakes and slides where you live. One never knows WHERE an overdue quake will strike, and the Kern Valley Graben is one of the active though unusual faults in the system.

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Finances trump engineering

During my working life, I was a practicing geotechnical engineer. I've seen lots of deteriorating concrete structures. Roadway deicers (salt) and/or deleterious aggregate - cement interactions were usually the cause. I've also been involved in destroying many structures that were still functioning well. They were functionally obsolete and no longer served the present need. In many of them, the rebar looked just as pristine as when it was originally placed. The key is to protect the rebar from environmental degradation.

It is hard to estimate future needs and build accordingly. Budgetary constraints dominate the decision making process. If another firm convinces the client that they can produce a satisfactory product for less money, the client will place additional pressure to cut costs ... or jump ship. Do you think management was happy with an engineer who stood his ground? There were lots of downstream consequences to consider.

That said, I really enjoyed the links that DRS78750, Michael_Rudmin, and Bankers Slave provided. I spent a few hours yesterday looking at their websites. Innovators who have these niches really open the possibilities for alternates to the standard accepted templates.

Here's a 5 minute video showing a temporary test structure constructed of sand with bed sheets as reinforcement. They loaded it with Jersey barriers. According to standard accepted calculations, the factor of safety (when fully loaded) was 0.088. In other words, it carried over 11 times the weight that it was predicted to carry before failure should have occurred. I certainly wouldn't use bed sheets as reinforcement in a "real" project, but it highlights the inadequacy of our current state of knowledge.

Grover

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Concrete used to plug old oil and gas wells

Hundreds of thousands of orphaned and abandoned oil wells left over from the first rape and pillage of Pa are venting methane into the environment. Where is the plugging plan? Not one more permit for one new hole until all the others ard plugged. That should keep them busy for oh say a century or so.

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Victoria Bridge versus Champlain Bridge

The Victoria Bridge from Montreal was built in the 1860s if I remember correctly, for a railway off Montreal Island to the South Shore - as an iron tube on stone supports. It was later modified to add also automobile and truck traffic, and it has that scary (especially on a motorbike) steel grid roadbed. But it is still in use after all these years. It is seldom is closed or down to 1 lane for repairs, like the relatively recent Mercier and Champlain bridges on which we are spending tens of millions of dollars every year trying to keep useable. It seems that stone is a lot more durable than re-enforced concrete, especially with salt spread on roadways for winter de-icing, causing salt-water run-off and seepage.

We seem to have learned enough from bad experiences in Quebec, to stop using horizontal re-enforced concrete beams for overpasses after some collapses of these structures after less than 40 years. Recent construction uses steel for horizontal beams, and should be durable in the case of I-beams or channel shapes, which are open, inspectable, can have all surfaces re-painted and made of thick steel. I have doubts about some overpasses I have seen built recently with box beams which are 4-sided, closed, and made of thinner steel, that can provide similar initial strength with less weight. I think that this design can eventually trap moisture and salt water inside and corrode from within, without it being visible or repairable. The thinner steel will also take a lot less time to rust through under these conditions. By the time we learn the lesson from this, we could be in a very different world for energy, materials and financing constraints.

Doug

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Entropy

The corrosion and eventual failure of steel reinforced concrete is just one example of Entropy - a law of physics that states everything returns to its natural state, or from order to disorder.  We use energy to alter the condition of something, but it will always eventually return back to the way it was.  The moment you finish cutting the grass in your yard, it begins to grow again (that's entropy).  As soon as you finish painting the house, it starts to age (entropy).  My wife often complains that as soon as she finishes cleaning the house, it starts to become dirty again (I've learned not to respond unsympathetically, "Of course it does - it's a law of the universe").  As it relates to this article, the trick is how to postpone the entropy (or maximize the lifespan) of our infrastructure by utilizing the most efficient use of energy and resources.

I have been the general contractor on three houses and another large structure I built for myself utilizing ICFs (Insulated Concrete Forms), with the first being a home built in 1999.  Although ICF construction is great for energy efficiency, it does not solve any of the problems noted with rebar.  In ICF construction, a foam block is used as the form and typically consists of approximately 2-1/2" of foam on both the inside and outside.  The inside of the form is about 6" wide (or larger) and contains webbing onto which steel rebar is attached and then the concrete is poured.  If there is a problem with steel rebar degradation, then ICFs will provide no improvement over precast or poured-in-place concrete onto which insulation is subsequently attached.  Unfortunately, I just finished utilizing ICF construction for my current house that was just completed a year ago (Chris - couldn't you have written this article a few years earlier?!).  I used steel stud framing, suspended concrete slabs and all PVC trim to minimize any organic material that would degrade over time, and thereby hopefully last hundreds of years (or so I thought).

As the previous owner of a large property management company, one of our primary functions was the constant maintenance and repair of buildings and grounds.  I witnessed the poor quality of current wood-framed home construction that is prevalent everywhere, and wondered how long these structures would last.  Considering that older buildings utilized more massive structural members, how many 300-year old buildings are still standing in the area where you live?  How about 200-year old or even 100-year old buildings?  I live near Williamsburg, Virginia, and almost none of the colonial buildings you see there are original.  They have all been rebuilt.  How are we going to rebuild the millions of homes constructed just during the past few decades when fossil fuels and resources become scarce?

Just over a hundred years ago, labor was relatively cheap and materials were expensive.  Since that time (thanks to abundant and cheap fossil fuels), it has reversed - labor is now expensive and materials are relatively cheap.  In the not-so-distant future, I believe labor will be expensive and materials will be expensive.  Then what will we do with all of the massive amount of degrading homes and infrastructure we have built?

Chris's article initiates the critical discussion and importance of building things to last, particularly while we still have the resources available.

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Residential Concrete

Perhaps reinforced concrete used in homes is less of a problem than that which is exposed to the elements? I just built a new home for a client on a site where 2 old cabins had been situated. The cabins were gone but the slabs remained. The structural engineer had us leave the slabs and cap over them. They were about 50 years old and looked solid. We doweled into them in a few spots, but mostly covered them with compacted fill and poured the new slab about 2 feet higher off grade.

Since residential slabs are almost 100% shielded from elements by the structure on top and the vapor barrier underneath, I have to wonder if they won't perform better than the bridges that allow moisture and air to contact the rebar?

 

 

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Rebar and Concrete Failure

After my previous submission, I performed a little research about the advisability of using rebar in concrete.  I am not an engineer, but information searches do report that rebar used in marine and bridge construction is placed under greater stresses than normal building construction.  In building construction, it is critical that rebar not protrude through the concrete, or even be within a few inches of an exterior wall.  Concrete is somewhat porous, and that moisture can continue the oxidation of the steel near the surface and cause it to expand.  The new void allows space for more moisture, resulting in more oxidation and expansion.  The area near the surface subsequently fails, and is called spalling.  If you look at the picture Chris posted at the beginning of this article, you can see that the rebar lies within a few inches of the surface - which was a mistake by the installation contractor.  Had the rebar been placed a little deeper into the concrete (with no exposed ends), it likely would not have failed.

You can read more about the subject at: https://www.quora.com/Why-do-highway-builders-allow-rebar-to-rust-before-pouring-concrete-Isnt-that-eventually-going-to-destroy-the-concrete

 

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Thank you Chris.........FINALLY!!!

I am a builder and have blogged about this issue with concrete before and have almost NEVER seen any mention of the issue of rebar concrete. I have seen the Pantheon as well: 2000 years and unsupported and unreinforced. The first concrete highway built in the 19th century is somewhere in new England and was unreinforced and supposedly still in use Concrete spalls from the oxidation of rebar and other causes. That is well known. Now we are finally starting to see "Greenbar" being specified which is green epoxy painted steel rebar. It may work real well but has not stood the test of time and bending it too much can cause it to crack breaking the bond. Other metals have been tested like aluminum bronze rebar which could last forever in concrete but it is a bit pricey. The other issue is how much energy is used to make concrete from limestone. Because it takes so much energy it SHOULD last 2000 years and using rebar which wont corrode within it is an obvious mandatory step. Failure in corrosive environments really speeds up the corrosion. Salt is used on roads and just kills concrete bridges. The Interstate bridge in MN that failed lasted what 30 or 40 years? And what did they replace it with?  you guessed it. Corrosion resistant rebar should be code everywhere for all concrete. Another issue is why not use steel bridges instead of concrete? They last a long time and the new coatings and alloys give them exceedingly long life. And why not build rail bridges instead of car bridges? How much longer will we have petroleum based private automobile transportation after oil becomes scarce or expensive? Steel bridges are fantastically cheaper than concrete, last a long time and are completely recyclable and repairable as well with cheap labor and simple tools. There are rail bridges in India over 100 yrs old. Did you think about concrete dams and concrete port structures? A failure of a main concrete dam say on the Columbia could cause cascading failures of the dams downstream. The dams fortunately are extremely thick but had they used corrosion proof rebar, they would almost certainly last 2000 years. I am grateful someone with a large audience finally has addressed this problem.

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Manufacturing basalt rebar overview

Here is a link to an article that gives an overview of the manufacturing process for basalt rebar. Originally produced in Russia, now by a company in Houston, TX.

http://www.monolithic.org/link-to/basalt-fiber-rebar

"It is still somewhat more expensive than steel, so it is first being used where steel has disadvantages. It can quickly replace stainless steel and epoxy-coated steel on a cost basis when regulatory hurdles are cleared."

Here is a link to a reseller that will give you some idea what small quantities cost.

http://www.monolithicmarketplace.com/collections/basalt-rebar-products

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It looks like basalt is 4x the price of black steel.

Just looking at the site, it looks like basalt is about four times the price of black steel. It, like other rock, is still going to be subject to decay. Whether it's a better material or not, I don't know. The thing to do is to get some experimenal bridges done with basalt, and then watch them closely.

Or start with some experimenal slabs: make up several hundred of them, and then start breaking them, one each year. Put some through a wet freeze-thaw cycle, others through a high-chloride environment, still others in intense sun, some in an anoxic saltwater environment, and so on. See where the basalt does well, where it does badly. Each style will generate a data point every two or three years.

There's another design implied by the bag of basalt fiber: That is embedded steel or carbon fiber. Such concrete, AFAICT is called "Type ii" in Europe, though that has a different meaning in the US. We've done some experiments with that here, but it's nasty stuff to cast. It tears up your forms, your equipment, and your finishers' hands.

The basalt fiber may have worse problems yet: it could be very similar to asbestos. In that case, there's a huge demolition cost added.

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Victoria bridge

Dollar_bille,

Very good comment.

One additional thing: The Victoria bridge is a private bridge. It is owned by the CN.

We can assume that this asset is important to a private company's business and that maintenance was properly done.

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Tesla - Master Plan Part 2

Chris, can you comment on what Tesla is doing?  I'm fascinated by the story and I'm very much behind the company to succeed. Maybe there could be some synergies between PP and Tesla, would be cool.  I know every Tesla owner I've spoken to absolutely loves their car and would never go back to any other.

https://www.tesla.com/blog/master-plan-part-deux

Also, check out this video of their Powerwall and Powerpack products.

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perspective from Cleveland (no politics)

Here is the perspective from a friend in Cleveland who quite enjoyed the article, but is not a member. The bridge he refers to was indeed massive

 

BUT, the ancients of 100 years ago were very well aware of the problems with rebar, which is why:



1- reinforced concrete was 50% thicker than it is now;



2- interior reinforced concrete beams often had steel beam supports for augmentation;



3- the steel used for concrete reinforcement was always formulated for lowest corrosion from virgin steel (not reprocessed- reprocessed has higher carbon content- and while strong, it corrodes horribly fast);



3a- prestressed concrete was manufactured not by concrete companies but by steel companies so the formulation could be controlled; Truscon Steel & Concrete Truss Company built stuff like that. They were a division of Republic Steel. They also sidelined in steel windows. My house has them, circa 1940. The bathroom window is wet inside pretty much November thru April. 75 years if this. For decades it showed a fine layer of rust. It made no progress and my linseed paint job has, for nearly a decade now, arrested it completely. The metal shows no loss at all. A modern formulation would likely corrode to perforation in under 20 years. And this is the stuff we use now in reinforced concrete!



4- old buildings like our destructed schools used reinforced concrete as above but primarily on the weather-protected internal structures, with outside walls being built from brick and hollow clay block that allowed moisture to breath out of the building and not collect inside so as to protect the concrete as well as the whole of interior materials. These methods together formed an edifice good for half a millennium or more by design.



5- NONE of the above is true any more.



Even old  overbuilt bridges like the original Fulton road bridge near the zoo here was done with the above in mind. The bridge had long looked awful especially at the end, and by today's standards would be deemed to be near collapse. And it was deemed such. So when they proceeded to blast it to pieces into the valley there, --Nothing Happened. It was still standing much to the "modern's" chagrin. So they rescheduled and tried again. Nothing Happened. It was still standing. Finally, the third try brought it down, but in three huge sections. Those sections had to be jackhammered to pieces bit by bit.



The decline of empire is a strange place to be!

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PaulJam
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fascinating topic!

Fascinating.  The Dam discussion brought me here. The type of insights and perspective offered by this article is why I pay my monthly fee. 

Any thoughts on how this knowledge pertains to nuclear reactors – are not most of them built out of reinforced concrete??

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