The shear walls on the building towered to a height of approximately 85 feet and had architectural concrete requirements due to their permanent exposure to public view on the outside of the building’s facade. Wayne Brothers used a climbing formwork system to form and pour each shear wall in four to five lifts ranging from 14 to 16 feet in height. SCC was placed into the formwork through a port in the bottom of the formwork. When designing the formwork system, full liquid head pressures were allowed in order to support the bottom-up pumping method.

When pumping SCC from the bottom up, the concrete forms are rapidly filled to the final pour height without any delay or temporary stoppage of concrete placement. With the force of the concrete rising in the formwork and rolling up the face of the formwork, air voids are forced out and virtually no air voids are visible on the face of the concrete once the forms are stripped. Along with the increase in quality, SCC also allows for reduction in concrete placement efforts.

Wayne Brothers’s scope of work on the FSU project consisted also of foundations and foundation walls. The crew’s work began in late 2011 and finished in early 2012.

With the combination of SCC and high-quality form facing, the efforts put forth by Wayne Brothers resulted in high-quality architectural finishes that will be seen for years to come.

Learn more about Wayne Brothers.

Daniel Wayne is the project manager at Wayne Brothers Inc., Kannapolis, N.C.

The analysis covers the entire life cycle of concrete in all its different types of production, such as ready-mix and precast.

This new method has been specially tailored for the sustainable market. “With this very versatile tool, we can even better support developers, architects, engineers and concrete suppliers when it comes to technical and economic performance as well as environmental impact in their projects,” says David Bowerman, Regional Business Segment Manager Admixture Systems at BASF. The BASF team supports customers using the “Life Cycle Analyzer”, both in evaluating environmental fingerprint of their products and in understanding the sustainability benefits of concrete. “Data availability has been recognized as one of the discouraging factors for sustainable construction. The new Life Cycle Analyzer is contributing to filling this gap and accelerates the development of sustainable solutions in concrete for our customers,” Bowerman explains.

The BASF “Life Cycle Analyzer” assesses the environmental profile of concrete based on selected indicators, such as Global Warming Potential (also known as “carbon footprint”), Primary Energy Demand or Acidification Potential. In addition, it evaluates the cost impact, in order to determine the eco-efficiency. The parameterized model is based on the European Standard EN 15804, which defines core rules for the product category of construction products. The tool allows quick calculation of the environmental and cost impact of different concrete mix-designs, allowing direct comparison of different scenarios. The model defaults to widely recognized European databases, but has also the flexibility to import material-specific or locally available data. In addition to the life cycle assessment of concrete, the calculation and the derived report represent the basis for a concrete Environmental Product Declaration (EPD), giving also input for most recognized building certification schemes (DGNB, BREEAM, HQE and LEED).

Sustainable solutions for concrete gain importance
Both private and public sectors are seeking improvement in sustainable construction. This trend is supported by the expanding network of Green Building Councils worldwide and the growing acceptance for certification systems for sustainable buildings. Consequently, this does create opportunities for innovation in all stages of the construction value chain. The material choice, e.g. of concrete, in the early planning stages of a construction project gains more and more importance in reducing the environmental impact of a building. This opportunity complements measures applied during the use phase of buildings, in particular by improving thermal insulation and energy management.

BASF’s “Green Sense Concrete” approach
The “Green Sense Concrete” approach represents the various initiatives of BASF’s Construction Chemicals Division towards more sustainable concrete. These initiatives comprise optimized services, products and tools under the respective local norms and standards, enabling environmentally preferable, cost-effective concrete that meets, and often exceeds, performance targets.

Sustainable solutions for concrete thanks to BASF’s innovative admixtures
To capture the full potential of clinker reduction in concrete by using composite cements and/or supplementary cementitious materials like fly ash, blast furnace slag or silica fume, BASF has successfully launched X-SEED, an engineered suspension of crystal seeds based on Calcium Silicate Hydrates (CSH) nanoparticles. X-SEED boosts the hydration process of fresh concrete in the early age (6-12h) and promotes concrete hardening at low, ambient or even heat curing temperatures. The ecologic, economic and social impacts of X-SEED throughout its life-cycle in a precast production were investigated using BASF’s SEEBALANCE methodology, with the result that the overall Socio-Eco-Efficiency Balance is remarkably increased compared to the solution without X-SEED. The hardening acceleration by adding X-SEED to the concrete mix-design opens remarkable optimization potential in terms of energy reduction, material optimization, process efficiency, flexibility, and achieving high quality specifications. Ultimately, X-SEED does not only save overall costs, it also provides extremely positive influence on energy and climate balance.

Smart Dynamic Concrete is a concept for a new generation of highly fluid concretes for day-to-day applications. It enables a high workability of concrete with easy to produce and robust concrete mix-designs, even with low cementitious content. Thanks to its self-compacting characteristics this concrete does not need to be vibrated, which means noise and health hazardous vibrations for the workers at jobsite can be avoided. Installation costs are drastically reduced, and the environment profits from lower usage of energy- and CO2-intensive cement.

Owen Covington

Reporter – The Business Journal

It’s been about five months since Caterpillar celebrated the grand opening of its new Winston-Salem plant, and since then a staff of 212 employees has been hired and is now producing about two axles per day.

But the sounds of construction still fills the inside of the 850,000-square-foot plant, even as production of mining truck axles is starting to ramp up.

Rusty Davis, operations manager for the plant, told a group of close to 150 Friday during a lunch and tour hosted by Winston-Salem-based real estate investing banking firm Wharton Gladden that a “large portion” of the plant’s $426 million total budget is being spent this year. The event was part of Wharton Gladden’s ongoing monthly business luncheon series that focuses on the Triad economy.

Most of Caterpillar’s investment this year will be in the machining equipment that will eventually fill the west end of the plant, and turn out the parts needed to produce the massive truck axles that weigh tens of thousands of pounds. Equipment to machine housings and shafts is now being installed, but a 100,000-square-foot space that will be home to $80 million in machining equipment that will be used to create front and rear spindles is still being finished by construction crews.

The first machining operations — to create banjo housings for the axles — should begin next month, but the entire machining operation won’t be fully ramped up until the beginning of next year, Davis told The Business Journal.

Until then, the plant has had to rely on parts machined elsewhere, and that’s slowed production to some extent. Davis said the market’s inability to meet Caterpillar’s high demand for cast steel parts that are then machined is also impacting production times.

The plant today seems relatively quiet, compared to the activity and sounds expected to fill it once production is in full swing. Eventually, the plant expects to be turning out about 10 axles a day, with a staff of about 500.

The novel process relies on a highly controlled extrusion of cement based mortar, which is precisely positioned according to computer data. The researchers believe the process has the potential to create architecture that is more unique in form and claim it could create a new era of architecture that is adapted to the environment and fully integrated with engineering function.

“The research here at Loughborough University gives us tremendous opportunities,” said Xavier De Kestelier, associate partner at Foster+Partners. “We are able to have a little peak into the future, to see what would construction will be like in the next five to ten years.”

Professor Simon Austin, co-investigator at Loughborough University added: “We have shown how additive manufacturing can be developed to create large structures, such as panels and walls, with precisely controlled voids within them.”

The 3D Concrete Printing (3DCP) project was funded by the EPSRC through the Innovative Manufacturing and Construction Research Centre at Loughborough University.

The researchers are currently moving the system from a 3-axis gantry to a 7-axis robotic arm in order to maximise the printing quality, speed and size. They are confident that the technology will have a bright future in the construction industry.

The U.S. data-center construction market increased to about $15 billion today from about $5 billion in 2000. According to a study commissioned by computer software giant Microsoft, that number is expected to increase to $20 billion by 2020. But the amount of energy and uptime required to power the facilities has made it difficult for data centers to achieve LEED certification.

“We started to realize that there was this project type that was growing in the industry while not growing on our list of certified projects,” says Corey Enck, director of LEED technical development with the USGBC. “There was a big disconnect that we felt could be addressed.”

The data-center requirements, which will go into effect in November as part of USGBC’s updated LEED 2012 standards, will require two systems to be modeled for each project in order to show its power utilization effectiveness: one for the building’s actual energy costs and another solely for its IT energy costs. Combined building and IT energy use must be 10% below the current ASHRAE 90.1-2010 baseline, and a 30% savings from the facility’s non-process load is required.

“They’re instituting more of a monitoring and testing-based certification as opposed to a standard benchmark certification,” says Terence Deneny, vice president of New York City-based Structure Tone Mission Critical, which has built a number of data centers.

Deneny said the increasing density of computing infrastructure makes it important for the industry to discover how to save energy. “This is a sector looking for some direction in terms of sustainability,” Deneny says. “I don’t think there’s a way to reduce the energy required to power a data center, but there is a way to design and operate a facility where you make the most effective use of that energy.”

The concrete floor of what will be Toronto’s biggest fish tank, in the city’s first tourist attraction in two decades, is down. Now we wait for sharks.

Construction crews at the Ripley’s Aquarium of Canada site south of the CN Tower poured the massive, 40-centimetre-thick pad on Saturday. Finishers worked until the wee hours of Sunday, then left the slab to cure for two weeks.

“We did it in one continuous pour so there aren’t any ‘cold joints’,” that could make a leaky seam, said Joe Choromanski, Ripley’s vice-president of husbandry, in an interview from the company’s Orlando headquarters.

“It’s huge — it’s a huge exhibit,” he said of the 2.8-million-litre shark tank, the centerpiece of the $130 million aquarium (including $11 million from the Ontario government) set to open in summer 2013.

Construction is now about one-fifth complete, Choromanski said, adding that this winter’s warm temperatures helped keep work on schedule.

Visitors will glide through the tank on a moving sidewalk, looking up and around at creatures including four-metre-long sand tiger sharks, stingrays the size of area rugs and otherworldly sawfish.

In total, various tanks will be home to more than 13,500 marine and freshwater fish in 5.7 million litres of carefully formulated solution that will start as Toronto tap water.

Ripley’s, owned by B.C. billionaire Jim Pattison, operates aquariums in Gatlinburg, Tenn. , and Myrtle Beach, S.C.

Choromanski said Ripley’s has a special concrete formula that includes fly ash, a byproduct of burning coal, to make the concrete extra waterproof.

And because sharks have a highly developed sensitivity to electrical fields that leads them to distant prey, no wiring is laid under the tank’s thick bottom slab.

“It costs a lot of money to reroute those conduits all the way around the perimeter of the building,” said Choromanski, “but we found over the years that even a tiny bit of stray voltage will drive sharks crazy.

“It was a learning curve for our (Toronto) contractors, who couldn’t understand why we go to the trouble of taking the long way around.”

The fish will start arriving in spring 2013.

IRA FLATOW, HOST:

This is SCIENCE FRIDAY. I’m Ira Flatow. If you’re a regular listener to this program, you know that one of my favorite topics is concrete. I know it sounds weird. It is a fascinating material, though, with a fascinating history. It’s everywhere, right. We use it for buildings, bridges, dams, roads. In fact, concrete is used more than any other manmade material in the world.

Right, we all take it for granted. A few of us know about its creation and about its development. We like to watch it being poured, like to watch it, you know, being worked. But, you know, the story of concrete is one that spans thousands of years, has touched the lives of rulers, inventors and architects, both famous and infamous.

Even Thomas Edison once owned the biggest concrete plant in the world, actually makes cement. My next thought that was an important story to tell us, along with a dozen others, and hey, I couldn’t agree more with him. Robert Courland is a historian and author of “Concrete Planet: The Strange and Fascinating Story of the World’s Most Common Manmade Material.” He joins us from San Francisco. Welcome to SCIENCE FRIDAY.

ROBERT COURLAND: It’s good to be here, thank you.

FLATOW: You know, whenever – and I corrected myself, I think – whenever I talk about concrete, and I talk to civil engineers, they say don’t mix up concrete and cement. That’s actually sort of a pun because you have to mix up cement to make concrete. So tell us the difference, would you?

COURLAND: Yeah, concrete is actually the binder used – I should say cement is the binder used to create concrete. It only represents perhaps a third of the total. The rest is sand, water and rocks called aggregate. And so they’re mixed together, and you’ve got concrete as the result. So instead of referring to a cement patio, it’s more properly called a concrete patio.

FLATOW: And I know how I got to be interested in the story of cement and concrete. How did you get your interest to write this book here?

COURLAND: Well, I actually began toying with the idea about five years ago, and it’s so ubiquitous that it’s almost invisible, and yet most of us know very little about it. So as I began researching the topic, I found all these incredible stories, and I was particularly amazed to discover that some of the most interesting figures in history were instrumental in its pioneering uses and applications, such figures as the Emperor Hadrian, Thomas Edison, who you mentioned, and – the Roman Emperor Hadrian, the architect Frank Lloyd Wright and a host of others.

FLATOW: Let’s talk about some – you tell some great stories in your book “Concrete Planet.” Let’s talk about one my favorites, which – because I’ve been to Kajaria, King Herod’s great harbor in Judea there, Kajaria, and the story of how that was built.

COURLAND: Yeah, King Herod, in the first century BCE, wanted a harbor. He wanted to have a rich kingdom, and if you wanted to have a rich kingdom, you need a harbor like everyone else, like in Alexandria and Piraeus in Athens and so on.

Now, the way you usually go about it is you take it an already existing bay or inlet, and then you extend one of the promontories to make it more sheltered, and then you start creating the jetties and the wharves and so on.

But unfortunately, ancient Judea didn’t have any of those natural features, and the only way it could be build was using this relatively new substance that the Romans had, concrete. So you could create a huge wooden form and then dump the concrete in it, have it sink in place, and you’ve got a – the result is a giant block that, you know, no current’s going to move.

And they had very strong currents, which was another problem there in Judea, right off the coast. So they – now planning such a venture is one thing, but actually doing it is quite another. The logistics that went into it were just phenomenal, comparable to the Pyramids and in some ways even more complicated. You needed to cut down something like 200,000 trees to build the huge concrete forms and also to fuel the lime kilns that were necessary to make the lime to mix the concrete with.

The trouble was at that time, the Mediterranean Basin had been mostly denuded of large trees. So where were they going to get the wood? So with the help of Rome, they found the wood in Central Europe and shipped it down the Danube to the Black Sea and then from the Black Sea to the Mediterranean and on to Judea.

And that was a tremendous effort right there, but they also needed the volcanic soil, which was another important ingredient, and so to ship it from Mount Vesuvius, the area around Naples, they had to use the ancient equivalent of today’s supertankers, these huge ships.

And they loaded thousands of tons of volcanic soil onto these ships and took it on to Judea, and it was an incredible engineering construction effort. In fact, the reconstructions of the harbor show a very modern-looking facility. In fact, it was state-of-the-art at its time. It had these special channels that were only open at high tide to flush out the harbor so it wouldn’t silt up.

And it was the second-largest harbor in the world, the first one being Alexandria to the south.

FLATOW: And it’s interesting, if you go to Israel and look at it now, you can imagine what it looked like…

COURLAND: Yeah because in that part of the Mediterranean, you’ve got a lot of subsidence. So it’s now under about 30 meters of water. The coastline’s just sunk. And there’s also a major earthquake fault that runs alongside it, too. But for several hundred years, it was one of the best in the world.

FLATOW: Why is the Roman Coliseum – you call it in your book the gold standard of concrete.

COURLAND: Well, actually not necessarily the Coliseum. The use of concrete for the Coliseum was primarily as a foundation material. But the Romans – I call it the gold standard because the Romans really perfected the use of concrete. In fact, they used it for about two centuries before applying it to their major construction efforts.

So they knew what to do with it and what not to do with it, and some of these things were – we didn’t wake up to until the second half of the 20th century. For instance, they would compact the concrete. They would just ram it into the forms to remove all air cavities and so on. And that made a denser material.

They also used very little water. They used only enough water to make it malleable, and that also gave it a much longer life and prevented cracking. They also realized that concrete wasn’t fireproof. So they used brick to clad their concrete walls, particularly after the great fire of 64 AD, the one that took place while Nero was emperor.

So they really knew a lot about how to use it, and again, we’ve only woken up to these things in the last couple of decades.

FLATOW: In fact there was a whole era where concrete was sort of forgotten about. Isn’t there a large (unintelligible)…?

COURLAND: Well, yeah, after the fall of the Roman Empire, dozens of technologies were lost, and one of them was how to make concrete. And so over 1,000 years would pass before people began rediscovering it. And the major progress in developing concrete was in 18th-century Britain, 19th-century Britain. And it was there that we eventually got the equivalent of modern concrete, which is called Portland cement, and that’s the standard concrete we use today.

FLATOW: 1-800-989-8255 is our number. We’re talking about concrete with Robert Courland, author of the book “Concrete Planet: The Strange and Fascinating Story of the World’s Most Common Manmade Material.” Is it possible to imagine a world today without concrete, what it might look like?

COURLAND: Sure, it would look like the 19th century. You would have more buildings built of brick and wood. There would probably be more people in the building trades. You would – the roads probably wouldn’t be as good as they are today. You would have more potholes. So it would look very antiquated in our eyes, simply because concrete would be missing from the visual landscape.

FLATOW: 1-800-989-8255. Let’s go to the phones, to Trevor(ph) in Redlands, California. Hi, Trevor.

TREVOR: Hi there. Great subject. I share your passion. Both my brother and I designed and built our houses out of concrete, and, you know, the walls, the floors, kitchen counters, everything. It’s an amazingly versatile product, and we have very different style houses. You know, and you wouldn’t even know they’re all built out of concrete necessarily.

FLATOW: So it doesn’t look like there’s a fortress, that you’re living in, a fortress of concrete?

TREVOR: No, not at all. My house is very modern-looking house and his is – looks like a castle, actually. It’s quite beautiful – something you might find in the Mediterranean or something. And there’s also a lot of great ways, I know now, to help make it a little bit more green building material, like using fly ash in it. I even read an article a while back about using the waste from power plants to mix the raw materials to make cement. I’m wondering if you know anything about that.

COURLAND: Yes, use of fly ash is very important. The – one of the problems with concrete today is that it generates a tremendous amount of CO2. And that comes from these huge blast furnaces that are used to kiln the limestone to create lime. And also, the limestone itself gives off carbon dioxide as it’s being cooked. And so it’s second only – I think it’s third only to power plants and automobiles in its production of CO2. Now with fly ash, you’ve got something that’s already there. And it’s wonderful material because you can use it to substitute not only the – you mix it with the cement and – so you don’t need as much lime, and also you don’t need to use as much sand in the material as well. It’s really wonderful. They’re working, right now, on even better concretes that should be out in the next few years.

FLATOW: Good luck, Trevor. There’s a new…

COURLAND: And some of these are even carbon negative.

FLATOW: There’s a new project.

TREVOR: Great. Thanks.

FLATOW: Yeah, thanks for calling. 1-800-989-8255. Let’s go to Brandon in Ann Arbor. Hi, Brandon.

BRANDON: Hey, how are you there?

FLATOW: Hey there.

BRANDON: I’m a tester in Ann Arbor area, or one of the concrete testers. We check the air pressure, take cylinders and mold them and put them in the laboratory and test them. It’s pretty entertaining. It’s quality control, quality assurance type of job.

FLATOW: Testing concrete did you say?

COURLAND: Yeah.

BRANDON: Yeah. We test concrete, usually on the side of the interstates or wherever it may be. And I get in, get out, take the test and tell the contractor and the concrete company what they got.

(SOUNDBITE OF LAUGHTER)

COURLAND: Yeah, that was…

FLATOW: Have you ever tested any old concrete that’s still around?

BRANDON: Old concrete, yeah. I mean, you can do a coring in…

FLATOW: Like Roman roads and things?

BRANDON: …get some old concrete. Roman roads – well, I was going to say, you know, these Roman roads are a lot better than the ones we even have right now. They’re crumbling after, you know, 10, 20, years, I believe, with salt on them.

COURLAND: That’s right.

FLATOW: Yeah. Thanks for calling. 1-800-989-8255. When do they start first reinforcing all this rebar and stuff inside the concrete?

COURLAND: Well, they did experiments in France back in the early 19th century, but it really didn’t take off until a contractor here in San Francisco, by the name of Ernest Ransome, who invented modern rebar, and it was much superior to what they were using before, which was something called barrel bands. Barrel bands were made by the million feet every year to – encase the wooden barrels, used for everything from wine to nails and what have you. So there was lots of it around, but it wasn’t as good as a rebar, and that’s Ernest Ransom’s big contribution.

FLATOW: 1-800-989-8255 is our number. This is SCIENCE FRIDAY from NPR. I’m Ira Flatow here, talking with the author of “Concrete Planet,” Robert Courland. And we’re going to bring in another guest now, because the cement, as we’ve said, is an ingredient in concrete. And during production, cement emits billions of tons of greenhouse gas carbon dioxide, as Robert was talking about. Researchers around the world are trying to create a greener form of concrete. Dr. Peter Stemmerman, a mineralogist at the Karlsruhe Institute of Technology in Germany – he is one of the investors of Celitement, described in the environmentally – to be environmentally compatible. Welcome to SCIENCE FRIDAY. Tell us, why are more environmentally compatible.

DR. PETER STEMMERMAN: Well, hello, Ira. It’s – our – Celitement is produced with just about one-third of limestone. And the limestone and conventional cement production and in our product is calcined. And from the calcination of the limestone, the CO2 is emitted. And over the whole process, would just emit about 50 percent of CO2 and just made about 50 percent of the energy too.

FLATOW: So it’s – so when you say the word – it’s Celite. It’s light in carbon, Celitement is how you’ve – is how you let it know. And how available is it?

STEMMERMAN: We are producing it now in a pilot plant in Germany, but it’s – I think about three to four years away from the market.

FLATOW: And you think it will be – make a real dent, because there’s a lot of concrete and – don’t the Chinese make most of the concrete or the cement in the world?

STEMMERMAN: Yes. In fact, we have about 54 percent of the cement production nowadays in China. And, yes, it’s a long way to go, as you, for example, have to do standardization, which takes five to 10 years if you want to be in the mass market. You have to start somewhere. And I think in about 10 years maybe, we’re really deep inside the market and we will change the scene.

FLATOW: Mm-hmm. Well, we wish you good luck. And thank you for taking time to join us today.

STEMMERMAN: Thank you.

FLATOW: That was Dr. Peter Stemmerman. He’s a mineralogist at the Karlsruhe Institute of Technology in Germany. What do you think about the Celitement, Robert?

COURLAND: Well, it’s very interesting. First, you’ve got to make it, you know, commercially interesting. And since this cement requires less energy to manufacture, then it’s theoretically possible to produce a low-carbon cement at a competitive price. And so I’m very encouraged by that. They’re also working on cements in England and in California here, from Culcalera(ph). And these actually produce less CO2. It emits less CO2. Or actually, it takes less CO2 than it actually generates, and so it’s carbon negative. And, again, it’s not on the market yet, but they say that within a few years it will be.

FLATOW: We’re going to take a break and come back and talk lots more about one of my favorite topics, concrete, with the author of “Concrete Planet: The Strange and Fascinating Story of the World’s Most Common Man-Made Material” Robert Courland. When we come back, we’ll talk about – why did Thomas Edison own the biggest cement factory in the world? I mean, he’s got the light bulb, you know, right? He’s got the recording machines. He’s got all that kind of stuff. What is he doing with cement? Interesting story. We’ll be back with the answers, so stay with us. I’m Ira Flatow. This is SCIENCE FRIDAY from NPR.

(SOUNDBITE OF MUSIC)

FLATOW: You’re listening to SCIENCE Friday. I’m Ira Flatow. We’re talking with Robert Courland, author of “Concrete Planet.” And a lot of people have questions about the mythology, about concrete. I want to get to them in the few remaining minutes that we have. Let’s talk about first – Robert, let’s talk about some mythology that concrete cannot be – cannot catch fire or be burned.

COURLAND: Well, it can’t. It’s fire resistant. It’s very fire resistant. Try to ignite a block of concrete and you’ll have a lot of problems. But the myth was that concrete is fireproof. And that was – the early concrete industry, the first half of the 20th century really promoted concrete a lot, saying that it was fireproof, and it’s not. When it’s exposed to high temperatures, it begins to defoliate. That means it begins to crumble away. And that’s why traditional bread and pizza ovens are made of brick and not concrete. If they’re made of concrete, they’d fall apart.

So the myth that concrete was fireproof was pretty much exploded by the second half of the 20th century. It should have been realized much earlier, after the 1906 earthquake and fire, but since concrete advocates dominated the engineering commissions that were formed to look into the damage caused by that disaster, they fudged the data to make it look like concrete had done very well in the fire, when in fact, it performed horribly.

FLATOW: And let’s go to another question here, and it comes in: we have concrete roads that are 2,000 years old, but why has not reinforced concrete stood up to the test of time?

COURLAND: Well, the steel that’s in reinforced concrete, which gives it its tensile strength, also dooms the material to a very short lifespan. Steel-reinforced structures, particularly those exposed to the elements, like I say, for instance, a freeway bridge are – will eventually corrode. The rebar will eventually rust, and as it rusts, its diameter expands by something like four or five fold. And then it destroys the concrete around it while it is being destroyed by the rust. And so that’s why concrete structures only last between, say, 50 and 125 years because of rebar corrosion.

We’ve got substitute rebars that have been developed recently. Some are made of fiberglass, reinforced polymer, some carbon fiber – are really good – a very interesting rebar that was recently developed is made of bronze-aluminum. Now bronze-aluminum is about the same strength as the mild steel used in most rebar today. And it’s – it doesn’t have any corrosion issues. So technically – theoretically…

FLATOW: Mm-hmm.

COURLAND: …you could build a concrete structure – reinforced concrete structure with bronze-aluminum rebar. And it should last a very, very long time.

FLATOW: Is that – are these new materials actually being used, or are we just talking about them?

COURLAND: Bronze-aluminum right now, they are doing experiments with it, and it looks – based on the experimental evidence, it looks very, very good.

FLATOW: What about fiberglass or…

COURLAND: Fiberglass – yeah, fiberglass, reinforced polymer rebar is now being used, and it shows wonderful promise. And so we really need to stop building with steel reinforced concrete, because we just have to demolish and rebuild the structure every 75 – 100 years. And, you know, it’s ridiculous. We could build buildings that last as long as the Romans, but we’re not going to be able to do it with steel as part of the element.

FLATOW: Interesting. Let’s go to the phones. Bradley in Nashville. Hi, Bradley.

BRADLEY: Hi, Ira. You may have touched on this because I tuned it late. Would you ask Mr. Courland if he could comment on the composition and construction of the dome of the Pantheon, which was designed and constructed by Hadrian in 135 A.D.

FLATOW: Yeah, he talked about that.

COURLAND: Yes. The Pantheon is…

BRADLEY: OK. Sorry. I didn’t hear…

FLATOW: No. He hasn’t talked about it yet. Go – well, we’ll hear it now. Go ahead, please, Robert.

COURLAND: Yeah. The Pantheon is an amazing structure, and, unlike the Parthenon in Athens, the Pantheon in Rome is still in good shape. It’s been in continual use for 1,900 years. And it was probably designed by the Emperor Hadrian who was one of the most brilliant emperors ever to rule during the empire. And he was always fascinated by domes.

And when he was a young man, before he became emperor, a famed architect by the name of Apollodorus made fun of his fascination for domes, which Apollodorus called pumpkins.

So when Hadrian came to power, he decided to, you know, design a building with a pumpkin, the likes of which would amaze the world. And he did that with Pantheon. It’s so incredible that when people visit it for the first time, they often assume that the portico, the part of the temple, the front part, is Roman, but that the rotunda and the dome were added in the 19th or 20th centuries because it’s too modern looking. It’s vast. Its 143 feet across and it still remains the largest unreinforced concrete dome in the world. And it could have only been done with concrete because of the plastic qualities of concrete, the ability to, you know, form it into any shape you want.

FLATOW: And you’re saying that if it has been done with reinforced concrete like today, it would’ve been gone in 100 years.

COURLAND: If it has been built of reinforced concrete, it wouldn’t have survived the empire that build it.

FLATOW: Could we still build roads without reinforcing in them today? You mentioned about the other materials. Could you still build that.

COURLAND: And that’s very interesting because concrete, by itself, has tremendous compressive strength. So assuming that a, you know, road is well-bedded, so you’re not going to have any lateral displacements if cracking occurs, you should be able to do it without reinforcement. And there’s a – the oldest concrete street in the world is in Bellefontaine, Ohio, is built, I think, around 1890 and it’s in wonderful shape and it was built of unreinforced concrete.

They turned it into a pedestrian zone because they wanted to preserve the original concrete surface, but it’s – not only has it stood up well after well over a century, but it also has required far less maintenance that the other nearby roads. So we have an example of unreinforced – and the Romans, too, you know? They used unreinforced concrete and their creations are still with us today, like the Aileen(ph) Bridge in Rome. It bears the traffic of cars, not just oxcarts and people as it originally did, but, you know, it holds up pretty good loads.

FLATOW: All is this fascinating stuff, and I personally wanted to talk about concrete and cement all the time. Concrete — cement and water, I mean, which get together, you know, to make concrete. So two substances are my favorite stuff to talk about, and this book is terrific to read “Concrete Planet: The Strange and Fascinating Story of the World’s Most Common Man-made Material” Robert Courland, thank you for taking time to be with us today and…

COURLAND: Oh, thank you.

By Jason Palmer
Science and technology reporter, BBC News

The precise structure of sea urchins’ strong spines has been unravelled – and the find may contribute to stronger concrete in the future.

The tough spines are known to be made of calcium carbonate, which has a number of naturally occurring forms, some more brittle than others.

X-ray studies now show they are built from “bricks” of the crystal calcite, with a non-crystalline “mortar”.

The results are reported in Proceedings of the National Academy of Sciences.

The spines serve as a defence against predators, hard and at the same time shock-absorbing. As a result of these properties, the spines are among the most-studied biomaterials.

But efforts to understand exactly how they are put together have yielded confusing results.

“Some people were arguing that the spine is a single crystal, and others who were looking at the mechanical properties were arguing that it’s more like a glassy material,” said senior author on the research Helmut Coelfen, from the University of Konstanz in Germany.

He told BBC News: “It still hasn’t been resolved.”

If the tough spines were single crystals, they should break cleanly along planes, as does mica or slate – but instead they break roughly, as glass or ceramic might.

To investigate further, the team started with sea urchin samples gathered in Beijing, looking at them with increasingly powerful imaging techniques.

Basic recipe

Along the way they gathered up expertise and collaborators from seven other institutions, starting with a standard light microscope, moving on to electron microscopes and then on to X-ray crystallography at the European Synchrotron Radiation Facility (ESRF) in Grenoble, France.

“We started using more high-power techniques to go further down in the structure, and the further we go down, the more different modes of architecture and different organisations we find,” said first author of the work Jong Seto, also from Konstanz.

The team discovered the bricks-and-mortar structure was made up of 92% calcite crystals (the bricks) bound together with 8% of calcium carbonate that has no crystal structure (the mortar).

This basic recipe builds up a range of structures that become apparent at different levels of magnification, making it what is known as a mesocrystal.

“With the help of these different techniques we were able to understand from the nanometre scale all the way to the millimetre scale how everything is arranged,” Dr Seto told BBC News.

Mimicking nature’s solutions to the material challenges that sea urchins face could be helpful also for us on land, Prof Coelfen said.

“The most obvious application… is building materials, to get fracture-rsesistant materials by just copying or trying to copy that building principle,” he explained.

“We are already working with two major international companies trying to improve the properties of concrete by trying to order the little nanoparticles in concrete to make it tougher and more fracture-resistant.

Home building, private nonresidential construction and public construction all increased compared to October, the Associated General Contractors of America reported in an analysis of new Census Bureau data.

Association officials cautioned, however, that public spending will drop even further in 2012 because of delays in enacting needed infrastructure bills and planned cuts to many federal construction programs.

“Several segments of construction appear to be climbing out of a hole,” said the association’s chief economist, Ken Simonson.

“The new year should reinforce recent year-over-year gains in apartment, power, manufacturing and private transportation construction. But, November’s upturns in single-family home building and public construction may not be sustainable.”

Simonson noted that total construction spending rose 1.2 per cent in November from October and 0.5 per cent from the November 2010 level.

Private residential construction posted increases of 2.0 per cent and 3.4 per cent, with gains in single-family, multi-family and residential improvements.

Private nonresidential construction spending inched up a negligible amount from October, but gained 4.5 per cent compared to November 2010.

The construction economist added that the uptick in private nonresidential construction from November 2010 was widespread, led by manufacturing, up 12.6 per cent; commercial (retail, warehouse and farm), up 12.0 per cent; private educational, up 10.0 per cent; private transportation, up 9.2 per cent; and power (including oil and gas), up 8.4 per cent.

Most public construction categories shrank over the past 12 month period, although the two largest had mixed results, Simonson observed.

Highway spending increased for the sixth straight month, by 1.9 per cent, but was 2.2 per cent below the November 2010 mark.

Public educational construction was up 0.5 per cent for the month and 2.8 per cent year-over-year.

“Public construction segments face stiff spending cuts in 2012,” Simonson cautioned.

Association leaders said planned cuts to a range of federal building and infrastructure construction programs were likely to hurt the construction industry even as private sector demand finally rebounds.

They noted that the federal budget for 2012 includes a more than six per cent cut for construction programs and added that Congress is years late in passing much-needed water, aviation and surface transportation legislation.

“If lawmakers don’t act swiftly, they risk undermining a long-awaited recovery for the construction industry that could put tens of thousands of people back to work,” said Stephen E. Sandherr, the association’s chief executive officer.

“These cuts aren’t helping balance the budget, but they are keeping a major segment of our economy in check.”

BIRMINGHAM, Alabama — Researchers at Auburn University and the University of Alabama have teamed up to devise a new recipe for a concrete, one that has the potential to reuse a form of toxic waste, cut greenhouse gas production and introduce new technology to the world’s most common building material.

Jialai Wang at Alabama and Xinyu Zhang at Auburn are perfecting a process that takes a power plant by-product — coal ash — and uses it in place of cement in their recipe for concrete.

Their recipe also includes a futuristic ingredient, carbon nanotubes, and a new technique for making them. The nanotubes, which add strength, durability and conducting properties to the concrete, are produced by cooking an iron compound for 10 seconds in a microwave. The researchers have dubbed the result “Poptubes.” “It is very much like you cook the popcorn,” Wang said.

Concrete accounts for 70 percent of all construction materials globally. It has advantages such as easy application, but to make concrete you need cement. Cooking cement requires a lot of energy and results in the production of a large quantity of greenhouse gases.

Coal ash already sometimes is used as an additive in concrete, but most of the massive amount of coal ash generated nationwide is stored in landfills or ponds, where there is the potential for the trace toxic contaminants to leach into groundwater or wash into the environment, in the case of a catastrophic dam failure.

The Environmental Protection Agency is studying various ways that coal ash is reused to make sure the traces of heavy metal in it are bound up in the new applications and don’t leach out. Meanwhile, Wang, Zhang and fellow collaborators have received a $450,000 grant from the National Science Foundation to further the development of the concrete alternative. Their method of producing nanotubes also has drawn attention in scientific journals such as Nature. Current methods of producing nanotubes involve high temperatures and special sealed chambers filled with inert gas.

Adding carbon nanotubes to coal ash concrete not only strengthens the material, it allows the material to conduct electricity. Electric conductivity could be used to enhance melting of ice on bridges or airport runways. It also could be used to monitor the integrity of the structure, since damage would cause a disruption in conductivity.

A start-up company based on the technology, Carbon Nanotube Engineered Surfaces LLC, has been formed and is hoping to win funding through the Alabama Launchpad contest, a competition for start-ups seeking seed money.

Black Warrior Riverkeeper Nelson Brooke said he wants any plans to reuse coal ash carefully studied before being widely applied. A safe, proven method of recycling would be preferable to storing coal ash in ponds and landfills, Brooke said. But he said that would not, in his opinion, make up for coal’s environmental toll. “I certainly see red flags when coal ash is referred to as environmentally friendly or eco-friendly,” Brooke said.

Nanotubes also have provoked concern in some quarters, because with their tiny size they can pass through barriers of living cells, potentially causing inflammation or disease.

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