Engineering set for smart revolution
By Julie Clothier for CNN
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(CNN) -- In a few years from now, the structures in your town will be made from concrete that can bend, the bridges will automatically alert authorities when maintenance is needed, and buildings will tell their occupants whether it is safe to re-enter after an earthquake.
Experts say buildings, bridges and highways will benefit from developments in smart technology, ultimately making infrastructure much safer for humans.
"Today, new information technologies are accelerating a quiet revolution in how society can better protect and manage expensive infrastructure assets," says Professor Jerome P. Lynch, of the University of Michigan's (U-M) department of civil and environmental engineering.
Lynch is one of a group of scientists at the university who has developed a low-cost wireless sensor that can monitor the "health" of structures.
Miniature computers are integrated into the sensors, enabling them to not only collect the data but also monitor for signs of damage.
"As a result, infrastructure systems installed with wireless sensor networks are capable of sensing their surroundings and rationally determining if they are in poor health -- ie. damaged," Lynch said.
The system, which costs a 10th of the price of some traditional sensors to produce, has already been installed in several bridges throughout the world, including the Alamosa Canyon Bridge in New Mexico and the Guemdang Bridge in South Korea.
Lynch predicted that by 2020, the practice of inspectors manually checking bridges for damage, which was both labor-intensive and expensive, would be redundant as the sensors became more commonplace.
Smart wireless sensors would also be fitted in new buildings, giving fire fighters early warning of potential structural collapse following explosions, and letting occupants know whether it was safe to re-enter a building after an earthquake.
"The wireless sensors are capable of recording the long-term behavior of the structure under its native loading conditions at a fraction of the cost of traditional methods," he said.
Lynch believed the sensors would completely change the way both public and private structural assets were managed.
Victor C. Li, Professor of Civil and Environmental Engineering also at the U-M, said concrete infrastructures, such as highways, bridges and buildings, would look the same in future but would behave very differently.
"Concrete will float, flex and bend; it will heal itself, it will weigh less than wood and be environmentally friendly like bamboo," he said.
"These next-generation infrastructures will be safer, more durable, more sustainable, and much smarter."
Li said bridge decks would require much less maintenance work, lasting at least 100 years.
"The built environment will co-exist harmoniously with the natural environment," he said.
"In fact, our infrastructure will be super-smart, being able to sense its own 'health condition' and report wirelessly to nearby monitoring stations with a self-diagnosis. In many cases it will conduct self-repair with no human intervention."
Li said the "next-generation" concrete already existed, in the form of "Engineered Cement Composites," or ECC.
The concrete has engineered micro-fiber "veins", which act as ligaments, enabling it to give instead of breaking when it is overloaded.
"It can flex 500 times more than normal concrete and still remain intact. Any cracks are so tiny that they are invisible to the eye," he said.
"Laboratory tests have already shown that the damage can heal itself with only water and carbon dioxide present in the air. One version of this material has a density similar to water, so it floats."
Li said engineers were investigating using the material to build earthquake-resistant buildings, crack-free bridge decks, and for flexible pipes that never leak.
He said there was a growing community of researchers in Asia, Europe and the U.S. conducting laboratory and field research on ECC and its applications.
The ultra-thin deck of the Mihara Bridge in Hokkaido, Japan, which opened to traffic a year ago, was built using ECC.