NASA computer will peer into concrete
(www.casperstartribune.net)
What do you do with one of the world's fastest computers?
You can forecast hurricane patterns. Or simulate how stars form, how nuclear bombs explode, or how a spacecraft handles solar winds.Or you can learn to mix concrete.Don't laugh.
Researchers at the National Institute of Standards and Technology in Gaithersburg, Md., are using a million hours of processor time awarded to them on the National Aeronautics and Space Administration's fastest supercomputer to analyze the billions of possibilities created by the collisions of tiny particles of sand, gravel and cement whenever a cement truck pours a sidewalk.
The different size and shape of each particle -- which scientists blow up to the size of weather balloons on their projection screens -- have a profound effect on the strength and durability of concrete and the time it takes to harden.
All of these, in turn, are critical factors when engineers create the right recipe for what has become a prime structural material in some of the world's tallest buildings.
The use of concrete dates to the Roman Empire, but thousands of years later, many of the material's properties remain a mystery.
"Several things about it are not really understood -- the durability, for one thing, is really not known how to predict," said Edward J. Garboczi, a member of the NIST team working on the project.
NIST is trying to create concrete that's more durable and easier to pour at construction sites.For the $10 billion concrete industry, the research is vital.
"You'll find steel in buildings, you'll find asphalt in roads and you'll find wood in houses, but you'll find concrete in all of those," said Iyad M. "Ed" Alsamsam, a structural engineer with the Portland Cement Association, an industry group whose members work with concrete and cement.High winds are less likely to sway skyscrapers that use concrete as a framing material, he said.
NIST researchers need NASA's supercomputer because of the nearly incalculable variations that go into making a typical batch of concrete.Concrete is a mixture of sand, gravel and cement.
The cement is made by mixing and heating limestone, clay and other materials.
There are national guidelines for the ingredients of cement, but they are fairly broad. Moreover, the sand and gravel that go into any concrete mix are locally quarried. So the exact mineral content of any two batches can vary, Garboczi said.
The particles that make up the mix also come in all shapes and sizes, which affect the durability of the finished concrete. Cement particles can range from 10 microns to 200 microns across (25,400 microns in an inch). The stones that make up the gravel can be anywhere from a half a millimeter to 2 inches in diameter.
There also are at least 40 types of additive mixtures -- polymers and materials such as corn syrup -- sold commercially to give concrete specific properties, such as strength, durability and curing time.
"Concrete can be different every time you make it, depending on what you're making it from," said William George, the NIST computer scientist who oversees the project.With 10,240 processors, NASA's supercomputer -- named "Columbia" -- is the nation's fourth most powerful in industry rankings, said Bryan Biegel, deputy chief of NASA's Advanced Supercomputing Division.
The $120 million computer takes up 15,000 square feet in a temperature-controlled room at the Ames Research Center at Moffett Field, Calif.
"The computer's named in honor of the Columbia crew," Biegel said.NIST researchers can already use a smaller cluster of the agency's 3,000 computer processors to simulate what happens when small pieces of concrete are mixed, George said.
But with Columbia, NIST will be able to scale up the work, modeling concrete blocks 10 times bigger and using the supercomputer to see -- for the first time -- how the size, distribution and shape of particles affect the flow and durability of concrete.
NIST will use the models as the basis for computer simulations in its Immersive Visualization Laboratory -- a large, dark room where computer simulations are projected onto garage door-sized screens.
They show what happens when millions of particles of sand, cement or any of concrete's ingredients are mixed and poured.In that lab, micron-sized particles of sand, created during a concrete research project in 2003, look like balls the size of weather balloons on screen.
Polymer fibers, millimeters long in real life, look like huge necklaces of pearls.
With a visor linked to the computer, the images become three dimensional and can be set in motion and manipulated, making viewers feel as if they have stepped onto a futuristic "holodeck."
The detail will be much greater with the help of the Columbia supercomputer.Meanwhile, concrete experts say this project is long overdue.
"There's a lot, lot, lot we have to learn," said Surendra Shah, a civil and environmental engineer at Northwestern University in Illinois.
"We should have been doing this 20 years ago, but people haven't realized the importance of the research.
"Distributed by the Los Angeles Times-Washington Post News Service
What do you do with one of the world's fastest computers?
You can forecast hurricane patterns. Or simulate how stars form, how nuclear bombs explode, or how a spacecraft handles solar winds.Or you can learn to mix concrete.Don't laugh.
Researchers at the National Institute of Standards and Technology in Gaithersburg, Md., are using a million hours of processor time awarded to them on the National Aeronautics and Space Administration's fastest supercomputer to analyze the billions of possibilities created by the collisions of tiny particles of sand, gravel and cement whenever a cement truck pours a sidewalk.
The different size and shape of each particle -- which scientists blow up to the size of weather balloons on their projection screens -- have a profound effect on the strength and durability of concrete and the time it takes to harden.
All of these, in turn, are critical factors when engineers create the right recipe for what has become a prime structural material in some of the world's tallest buildings.
The use of concrete dates to the Roman Empire, but thousands of years later, many of the material's properties remain a mystery.
"Several things about it are not really understood -- the durability, for one thing, is really not known how to predict," said Edward J. Garboczi, a member of the NIST team working on the project.
NIST is trying to create concrete that's more durable and easier to pour at construction sites.For the $10 billion concrete industry, the research is vital.
"You'll find steel in buildings, you'll find asphalt in roads and you'll find wood in houses, but you'll find concrete in all of those," said Iyad M. "Ed" Alsamsam, a structural engineer with the Portland Cement Association, an industry group whose members work with concrete and cement.High winds are less likely to sway skyscrapers that use concrete as a framing material, he said.
NIST researchers need NASA's supercomputer because of the nearly incalculable variations that go into making a typical batch of concrete.Concrete is a mixture of sand, gravel and cement.
The cement is made by mixing and heating limestone, clay and other materials.
There are national guidelines for the ingredients of cement, but they are fairly broad. Moreover, the sand and gravel that go into any concrete mix are locally quarried. So the exact mineral content of any two batches can vary, Garboczi said.
The particles that make up the mix also come in all shapes and sizes, which affect the durability of the finished concrete. Cement particles can range from 10 microns to 200 microns across (25,400 microns in an inch). The stones that make up the gravel can be anywhere from a half a millimeter to 2 inches in diameter.
There also are at least 40 types of additive mixtures -- polymers and materials such as corn syrup -- sold commercially to give concrete specific properties, such as strength, durability and curing time.
"Concrete can be different every time you make it, depending on what you're making it from," said William George, the NIST computer scientist who oversees the project.With 10,240 processors, NASA's supercomputer -- named "Columbia" -- is the nation's fourth most powerful in industry rankings, said Bryan Biegel, deputy chief of NASA's Advanced Supercomputing Division.
The $120 million computer takes up 15,000 square feet in a temperature-controlled room at the Ames Research Center at Moffett Field, Calif.
"The computer's named in honor of the Columbia crew," Biegel said.NIST researchers can already use a smaller cluster of the agency's 3,000 computer processors to simulate what happens when small pieces of concrete are mixed, George said.
But with Columbia, NIST will be able to scale up the work, modeling concrete blocks 10 times bigger and using the supercomputer to see -- for the first time -- how the size, distribution and shape of particles affect the flow and durability of concrete.
NIST will use the models as the basis for computer simulations in its Immersive Visualization Laboratory -- a large, dark room where computer simulations are projected onto garage door-sized screens.
They show what happens when millions of particles of sand, cement or any of concrete's ingredients are mixed and poured.In that lab, micron-sized particles of sand, created during a concrete research project in 2003, look like balls the size of weather balloons on screen.
Polymer fibers, millimeters long in real life, look like huge necklaces of pearls.
With a visor linked to the computer, the images become three dimensional and can be set in motion and manipulated, making viewers feel as if they have stepped onto a futuristic "holodeck."
The detail will be much greater with the help of the Columbia supercomputer.Meanwhile, concrete experts say this project is long overdue.
"There's a lot, lot, lot we have to learn," said Surendra Shah, a civil and environmental engineer at Northwestern University in Illinois.
"We should have been doing this 20 years ago, but people haven't realized the importance of the research.
"Distributed by the Los Angeles Times-Washington Post News Service
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