Tell it to the Romans, who used concrete to build The Colosseum, which is still standing.
From E&E newswire – h/t to Marc Morano
Concrete’s life span is shortened by climate change — study
Published: Wednesday, October 15, 2014
Climate change may reduce concrete’s durability, with long-term consequences for buildings, roads and bridges constructed with the common material, according to a recent study.
Matthew Eckelman and Mithun Saha of Northeastern University focused their research on how infrastructure in Boston will be affected by the most extreme climate change scenarios.
They predict about 60 percent of Boston’s buildings will have some structural deterioration by 2050. Eckelman and Saha published their study results in the journal Urban Climate.
“Starting in 2025 is when [we expect] to see the concrete cover on buildings start to fail, assuming they were built to code,” Eckelman said.
Concrete is considered one of the most solid structures humans have engineered. Modern concrete structures and roads are further reinforced with steel bars to make the material less brittle. However, over time both carbon dioxide and chloride ions seep into the concrete and corrode the steel bars, called rebar. This corrosion expands the concrete, destabilizing it. Eventually, the damage becomes visible when the facade of a building cracks or chunks of concrete break off.
The amount of carbon dioxide in the atmosphere is expected to increase with climate change, and Boston in particular is vulnerable to chloride because of its proximity to salt water.
Under current building codes in the United States, buildings’ concrete coverings have to be about an inch and a half thick for the structures to last three-quarters of a century. However, the researchers noted that these building codes don’t take into account how climate is likely to change over that amount of time. When climate change is considered, buildings built today will likely last between 50 and 60 years, roughly 25 years less than if temperatures remained the same, the researchers said.
Eckelman and Saha said the biggest effect will likely be higher construction costs to reduce corrosion, like adding 3 to 12 millimeters of thickness to buildings’ concrete cover. This could increase building costs by between 2 and 4 percent.
The buildings most at risk in the near term are those built in the 1950s and ’60s because they are built with weaker concrete.
The American Concrete Institute, which provides guidelines for setting building codes, is going over its standards while taking into account global warming (Kevin Hartnett, Boston Globe, Oct. 12). — NH
Or, you know, you could just alter the cement chemistry for a chloride environment. Just like cement producers have been doing for decades in applications with high chloride exposure.
The stupid. It burns.
Haha, I’m in the cement industry, and you took the words right out of my mouth. The stupid really does burn with this story. They have no idea how how cement and concrete are made.
… and how long have you guys been trying to figure out how to make improved and corrosion proof reinforcing members? Like this is supposed to be “news.” (fyi, I’m sure they’re using the terms cement and concrete interchangeably… yes the stupid is strong there.)
The authors are civil and environmental engineers that, by virtue of this article, have sublimated into climate scientists. Thus, they’ve achieved infallibility.
The give-away is in the second sentence. “They predict about 60 percent of Boston’s buildings will have some structural deterioration by 2050.” The key word is ‘some’, which immediately fails to actually quantify the extent of the deterioration. How much is natural and expected? Is an extra crack or chip due to Climate Change? Nope. Not misleading at all.
With you there. Most cement made to standards is good but not all concrete is good. The reason for concrete “cancer” was the use of Calcium Chloride to give early strength growth. This has been banned. Other problems of using too much water, not enough cement in concrete mixes and insufficient cover over reinforcing, although in standards, is more difficult to police. There is good and bad concrete. Poor concrete is the fault of poor design, poor construction, & poor supervision it has nothing to do with climate or environment but government legislation and environmental restrictions on production and construction which raise costs (encouraging short cuts) are not helpful for getting a good outcome.
By the way the hydraulic lime used by the Romans was not all good quality nor were many of the structures built by the Romans. What remains was at the top of the quality curve. The dome of the Pantheon in Rome is an outstanding example.
@ur momisugly Tucker –
My first job out of college was as a laboratory inspector for ASTM’s Cement and Concrete Reference Laboratory. Blaine and Wagner (you may have heard of them) were two of the first people associated with that organization.
I can honestly say that I’ve forgotten more about Portland cement and concrete than most people will ever know.
Nor do they understand the reinforced concrete design process. I hate to say this but these people are idiots.
Concrete loves hot and humid. A warmer climate would undoubtedly increase the life of concrete in Boston. It’s rapid temperature swings and corrosives concrete doesn’t like, which is why additives and sealants are used, and why reinforcing steel often has corrosion protection. There is no substitute for good maintenance and good design, no matter the weather and climate.
I was in the Coliseum in Rome last year, and was amazed at the condition of the concrete, which was actually quite good. The Coliseum was built with rubble, bricks and other waste materials, as filler. The dome of the Pantheon (126 AD) is all concrete and in great shape as far as I could tell. The benign (warm) climate, which seldom freezes, has played a big part in the life of these structures.
I am confident that the concrete in Boston will be just fine if it is properly maintained, and just as confident that it will not be.
But ya know, they are right. Once places that didn’t freeze before start the freeze thaw cycle, their lifespan will be reduced.
Ot the converse. They believe there will be less freeze/thaw
as the globe warms. freeze/thaw rips up concrete roads.
Not as bad for vertical surfaces I guess.
“Hey you guys, quit burning those Christians!”
Well, they’re gonna need SOMETHING to explain why that new Bay Bridge in SF fails waaay early.
Roman concrete is not the same concrete we use today. Today we use Portland cement. The Romans used lyme and volcanic ash. Their formula was vastly superior to the modern formulation. Today’s concrete has a relatively short lifespan.
http://www.romanconcrete.com/docs/spillway/spillway.htm
Glad you had something concrete to add to the discussion instead of just Roman around like the rest of us.
LOL. We still have a lot to learn from the ancients.
GROOAANNNNN
Way to kick some ash! 🙂
Mesopotamian hydraulic cement predated even the Romans use of pozzolans ground pumice, brick, pottery. The chemical resistance is in the hydraulic/non-hydraulic nature.
An acquaintance forms-carpenter told of earth collapsing under bridge forms and submerging them through the winter. Rather than blasting them, they were incorporated into the footings.
Hope this not too off-topic, but the Egyptians appear to have learned how to make concrete earlier still and (this is highly speculative) used the technology in the construction of their monuments.
Here’s a nice short article about the possibility that the Egyptians poured the blocks for the pyramids into molds, on site:
http://cementafriend.wordpress.com/2014/05/06/pyramids/
Actually, if I remember correctly (more questionable as time passes), there was an article several years ago by a Yugoslavian engineer (possibly in Science mag) that first claimed to have discovered the formula for a cement like substance used by the Egyptians to build their pyramids. He had produced several samples and claimed they were indistinguishable from the ‘stones’ used in the pyramids.
No poured blocks for the pyramids. The stone used is quite well characterized and sourced. The biggest mystery was always “how” the blocks were moved into place, and what became of the ramp afterward, which, of external would have massed nearly as much as the pyramid. Look up the “pyramid internal ramp hypothesis”. The idea is elegant and some recent supports the idea quite well. What is particularly elegant is that the ramp doesn’t have be removed since it was incorporated directly into the pyramid.
Did you draw these concrete conclusions from the aggregate data? Greater reinforcement may cement your thesis, before it all turns to mud….
Aging concrete is actually a huge issue.
http://www.usbr.gov/ssle/damsafety/TechDev/DSOTechDev/DSO-05-05.pdf
Cementafriend introduced me to the great engineer, John Smeaton (8 June 1724 – 28 October 1792). “He is important in the history, rediscovery of, and development of modern cement, because he identified the compositional requirements needed to obtain “hydraulicity” in lime; work which led ultimately to the invention of Portland cement. Portland cement led to the re-emergence of concrete as a modern building material, largely due to Smeaton’s influence.”
Now, as usual with disaster predictions from environmentalists, possible environmentalist regulations and sabotage of the compositional requirements for Portland cement would and could fulfill their own prophecies of failing cement.
Alan,
Lyme cement is not vastly superior to Portland cement. They each have their strengths and weaknesses, and the type used should be based on the purpose and need required. Therefore, one is not better than the other.
My first introduction to Lyme cement was the Tabby foundations used for the old houses in the Low Country of South Carolina. They were poured of lime, sand and water with broken/crushed oyster shells as aggregate. The lime was made by crushing and burning oyster shells.
You are of course correct. Steel re-enforced concrete has weakness too. If the steel is not clean of rust and not deep enough in the concrete it will oxidise, rust and will eventually cause the concrete to swell and fail. Also, it was the Romans who developed concrete that could set while in sea water.
The only thing that this sort of “research” seems to be doing is shortening the lifespan of a dollar bill in my wallet. It used to be able to rest there a day or two, but now it has a hard time getting to it in the first place.
This is true. Over-regulation, the continued use of special permits, and the banning of effective chemicals make it more and more difficult for most people to engage in commercial activity.
This then destroys culture, because the opportunities for individuals engaging in commercial activity naturally rewards hard work, innovation, and intelligence. Without commercial activity by all people, the welfare system rewards unemployment and drug use.
It also destroys purchasing power.
One more reason for the alarmists to start holding their breath.
I am at the point of starting a rumor “Global warmist who talk too much about this and that causing climate change are the cause of the climate change.” In other words I tired of hearing them. They make themselves look dumb.They wonder why you look at them like their crazy.
If you like their crazy, you can keep their crazy, There, there, those homeynyms (sic) will getcha every time, they’re everywhere.
Yep its gone from a lifespan of 2500 years from before Christ until 25,000 years with today’s technology
From the hyped “press corpse release” above ..
It is the SALT (mainly from the northeast’s need to spread salt over everything to prevent ice damage and clear roads and sidewalks of the frozen slush) that causes the steel to rust. It is NOT the CO2 that harms concrete or steel – instead the CO2 strengthens the concrete surface! (The article is correct on one point: A rust surface on carbon steel has a different, much larger crystal structure with substantial gaps and openings thattrap additional moisture and oxygen around the rusted material (Fe2 and Fe3 iron oxides) that does tend to expand and crack away (spall) the cover concrete from the rebar. But only if the rebar is set too shallow in the first place.
So, the CO2 affects ONLY the outside 3 mm of the drying concrete. Which will NOT affect the steel rebar INSIDE the concrete covered by – what should be 2- 3 INCHES (75 mm) of concrete. Rebar 1/2 inch (25 mm) from the outside surface
More important to look for corrupt Boston city manager that managed to spend more time and effort building a single highway tunnel than was needed for the Hoover Dam, Golden Gate Bridge and Panama Canal. Combined. But those projects didn’t also enjoy roof panels that were not glued on right either.
Oxidation (rusting) of elemental iron creates iron oxides ( Fe2O3, Fe3O4, etc), an exothermically favorable reaction. A volumetric expansion occurs with formation of the iron oxides, causing shear forces and subsequent flaking and spalling of the developing oxide layer. This presents fresh iron surface to free oxygen atoms and the cycle continues until the iron is consumed. Oxy-acetylene ‘torch’ cutting of irons and steels is a (very!) accelerated form of this reaction.
As more oxides form on and around the ‘rusting’ iron surfaces, the continuing volumetric expansion during oxide formation can create sizable tensile forces in the concrete surrounding the rusting ‘rebar’.
Additional stresses are created from the differing thermal expansion/contraction properties of steel rebar vs concrete, as a result of the daily and seasonal changes in temperature cycles (day/night, summer/winter).
When the combined stresses exceed the local tensile strength of the concrete, the concrete cracks or even spalls off, allowing more direct exposure of the steel to oxidation and corrosion. And so it goes…..
2- 3 INCHES (75 mm) of concrete. Rebar 1/2 inch (25 mm)
I think that should read 50 – 75mm
& 1/2″ = 12.7mm
Technically, yes – if any field worker were measuring concrete and concrete forms with a calculator and micrometer instead of a yardstick, measuring tape, and 2×4’s …. one should convert 1/2 inch to 12.7 mm . But, that is not the real world case of pouring concrete and bending rebar with sledge hammers and crowbars to fit inside a form made of plywood and 2×12’s … 8<)
I saw electrical transmission lines in the Ukraine in the 1990s that were – unusual – to a western eye. Instead of wooden poles and yards they used reinforced concrete. Apparently there’s a dearth of tall-enough trees in the former Soviet Union and metal had other important uses. The lower three to five feet of many of these poles was bare re-bar. The repeated freezing and thawing caused the concrete to crumble at and below the common limits of the yearly snow accumulation. I found myself wondering what a high wind would do to a line in that condition.
Am I missing something, or isn’t this about increased CO2 levels, not climate change?
Bingo.
And the climate change they are predicting is rising CO2 levels – not temperature, storms or dying polar bears.
This makes sense. CO2 has risen consistently. Probably due to man and fossil fuels – near certainly in my opinion..
But even if not it has still been a consistent rise during the time of ~800 years post-MWP.
This “alarm” is reasonable. And so is the anticipated mitigation (thicker concrete).
Somewhat OT, but I read somewhere (possibly on this site) that when Mt Pinataubo (sp?) went up, it released more carbon dioxide than all human activity ever has. Is this correct, and if yes, could someone point me to a reference, please. When I throw these sorts of factoids into discussions with warmists, I like to make sure I can back the statements up (unlike many statements warmists parrot, that sheer logic should tell them couldn’t possibly be correct).
The amount of damage done by 0.04% of CO2 is so much bigger than that of acid rain.
Interesting new example of climate alarmism. Do they have any suggestions on how to halt climate change without perturbing every living thing on earth? An unchanging climate has never happened before but now it seems to be a critical necessity. Its for the concrete, people.
Assumes that Roman concrete is the same.
a SIMPLE google check and one would have avoided the knee jerk response of comparing the two
to discredit the study.
why roman concrete has lasted so long when its structurally weaker.
http://www.smithsonianmag.com/history/the-secrets-of-ancient-romes-buildings-234992/?no-ist
eye rolling?
more like eye’s shut.
1. We have observational evidence that the colliseum is made of “concrete”
2. We have a study that says more C02 may shorten the lifespan of buildings in Boston.
One person can read these two and conclude that they are in conflict
But where is the conflict?
1. Maybe roman concrete is different than Boston concrete
2. Maybe the Boston study is flawed
rolling your eyes means you’ve concluded that 1 is not possible. This is a bias.
On its face either or or 2 is plausible. So, before passing judgment and settling the issue, a good skeptic
reads more.
I agree wholeheartedly. We need to avoid jumping to conclusions.
+1
No.
Roman concrete is a totally, completely different chemical, applied and poured in position completely different from modern cast reinforced concrete (including no rebar that could rust and cause spalling!) and contributes NOTHING to the story except distraction. Plus a usual snide implication “our new stuff is not as good as the old stuff” revisionism …
Re-read the story: CO2 does NOT degrade concrete performance. It is the too-shallow steel rebar that rusts and causes the concrete to spall. IF the concrete was improperly poured in the first place.
Then, these idiots compound the problem by assuming a skim coat of 1/2 inch could be applied successfully to prevent rust damage – when 1/2 inch (12 mm) of re-applied cover coat concrete will INCREASE sub-surface water/salt/chloride retention and subsequent rusting.
CAGW by press release. Bad data. Bad writing, wrong conclusions, wrong solution. All written around the “Greater CO2 is going to cause more problems and kill people….Unless we stop all progress and force more people into poverty.”
I beg to differ. The post posited the argument that concrete is long lasting, citing Roman concrete as evidence, and then raised the issue as to whether climate change could have any effect on the longevity of concrete. But at Steve and I pointed out Roman concrete is not the same as modern concrete, so any arguments concerning the longevity of “concrete” based on the lifespan of Roman concrete is not applicable. This is not to argue that climate change has any effect on the longevity of modern concrete. But as I pointed out earlier in this post, there is an issue with aging concrete and needs to be addressed and attached a PDF that talks about it.
As I have pointed out modern concrete can be made to last up to 16,000 years! So maybe build structures might struggle, but I still roll my eyes about the future of modern concrete. Special coatings can also be applied to extend the life of concrete.
http://wattsupwiththat.com/2014/10/15/eye-roller-concretes-life-span-is-shortened-by-climate-change/#comment-1763284
I own a cement block house with re-inforced concrete pillars, beams and suspended floor slab. I was told it would have a life of 100 years, some said 60. I am aware of the lifespan issue.
My problem is this:
Why not a study that just tells us about concrete’s failures in the coming years? Grrrrrrrrr. I suppose it’s one one sure fire way to get your grant application approved el pronto. This is what I am sick and tired of.
The Romans used more than one form of concrete. Pozzolana made with volcanic dust was used to produce concrete that was required to set under water but this material was not available everywhere and had a cost premium. The modern equivalents use substitutes such as furnace fly ash and have very similar properties.
There are thousands of bridges and other structures across Europe that were built with other aggregates including the Pantheon in Rome which used volcanic materials such as Tufa and Pumice to produce light weight aggregates. The modern equivalent in the UK uses fly ash from coal fired power plants to produce lightweight stable concrete blocks with good thermal insulation properties usually referred to as breeze blocks
There is no evidence that we are heading into any of the climate extremes used in this analysis. There is no question though that concrete and steel are vulnerable to weathering and there’s nothing we can do about weathering. The intent of the report is to impart worry, not science. BTW, they place the blame on a warming climate, not more CO2.
“Eckelman and Saha said the biggest effect will likely be higher construction costs to reduce corrosion, like adding 3 to 12 millimeters of thickness to buildings’ concrete cover. This could increase building costs by between 2 and 4 percent.”
That’s fine, as long as the cost of fuel, electricity, cereals, dairy, beef, fruits, wood, light bulbs, shipping, restaurant operations, and everything else don’t rise because of environmentalist regs and unnecessary add-ons.
Oh wait…
You don’t have to thicken the concrete.
Just so long as the reo has sufficient cover, is all that’s required. (hint: the reo could be futher inside from the surface).
It’s still a brainless study, as engineeers have been designing concrete structures for decades with the environment and soil acidity in mind.
Why are the CAGWers fearmongering about the shortened lifespan of concrete? If they had their way, we wouldn’t be using ANY concrete, since the production releases CO2 to the envrionment.
http://en.wikipedia.org/wiki/Environmental_impact_of_concrete#Carbon_dioxide_emissions_and_climate_change
“…The cement industry is one of two primary industrial producers of carbon dioxide (CO2), creating up to 5% of worldwide man-made emissions of this gas, of which 50% is from the chemical process and 40% from burning fuel.[“
Since it won’t last very long anyway… Yet one more reason not to make cement. A twofer! 😉
Alan don’t forget steel works they use carbon to extract oxygen bubbles from steel. The waste gas is co2
Stop.Just freaking stop climateers. What next, erectile dysfunction? Those of us that visit this site frequently know it’s responsible for psychotic breaks as is obvious by this article. But concrete? Please.
I thought that was already on the list.
Climate change does cause more rape (at least it has been said); so that speaks against erectile dysfunction.
Hey, I read that freezing weather damages concrete.
You hada ask.
—-
Agency: Environmental Protection Agency [2010]
A Human Health Perspective on Climate Change: Summary [Brochure]
http://www.globalchange.gov/browse/reports/human-health-perspective-climate-change-report-outlining-research-needs-human-health
The “study” confuses and conflates climate change, warming, increased CO2, and salt corrosion. Epic FAIL.
The answer to corrosion which is primarily from salt is stainless steel rebar. The increased upfront costs are paid for eventually by increased lifespan of the structure.
Eeek, does that also mean the 800 tons of concrete under each wind turbine.
http://docs.wind-watch.org/Cracks-in-onshore-wind-turbine-foundations.pdf
Oh no , they were right, it’s already happening.
Ok I’m not a chemist, so could somebody explain to me how CO2 effects steel. Chloride ions I get. CO2 not so much.
Copy and Paste from Wikipedia:
And those formations break apart the surface of the structure.
And this reaction can be prevented with the addition of a pozzolan such as metakaolin that reacts with the calcium hydroxide hydration product to produce more cementious material, negating the reaction with carbon dioxide, making the concrete stronger, denser, less porous and eliminating efflorescence. Further, the addition of acrylic polymers and other admixes provides an anti-corrosive coating to reinforcing steel and also makes the concrete less porous. The addition of crystallization admixes can make concrete virtually impermeable to water. Further still, various fiber additives eliminate even the need for steel reinforcement in many applications. With these kinds of additives, my concrete constructions will outlast my great-great grandchildren. Modern concrete formulations are nothing like those of the past.
According to my late uncle – a civil engineer/contractor – the recipe for the mortar is the main determinant in how concrete endures.
all alarmist stories with might, may and could are meant for the dustbin,
“Climate change may reduce concrete’s durability”
Brian R – Steel and iron corrode when there are 3 things present: iron, oxygen, and water. CO2 has little to do with it. CO2 *will* affect the lime (calcium hydroxide) turning it into calcium carbonate and making it gradually crumble – unless precautions have been taken. The Romans used volcanic ash (Pozzolan) in their concrete to stabilize the lime and improve the “cementitious qualities”. The Minoans knew this trick, and passed it along through the Greeks.
The Colosseum wasn’t built out of concrete, it was built out of stone with metal clamps to keep it in place (no mortar).
However, if you want to talk about impressing Roman concrete structures, you can’t go past the Pantheon, with it’s un-reinforced domed roof approaching 2,000 years old.
The Romans, as Alan noted above, used their own Roman cement, the chemical formula of which eludes us to this day. It’s worth noting that Roman concrete tends to be unreinforced, unlike today’s construction materials, and so doesn’t suffer from concrete cancer.
Help is at hand.
http://www.concretenetwork.com/concrete/concrete_cracks/preventing_concrete_cracks.htm
Even better help at hand
http://crystalfix.com.au/content/how-mr-crystal-works.html
and
http://xypexwaterproofing.com/products/concentrate.html