is a key component of the most widely used |
HOME-GROWN BRICKS |
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construction material on the planet . To make it , |
Despite working on the built environment , Dosier |
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limestone is heated to 2,700 degrees Fahrenheit , |
never lost her fascination with the natural one and |
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turning it into a powder , which is then resolidified |
the inspiration that biological production methods |
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when mixed with water and aggregates in a |
might hold for developing new construction |
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concrete mixer . |
technologies . |
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Like seashells , limestone is produced by the |
“ I was really interested in biomimicry and |
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natural precipitation of calcium and carbon to form |
how nature is able to produce all these amazing |
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solid crystals of calcium carbonate . The energy- |
materials using just the surrounding supply chain ,” |
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intensive process of breaking those crystals back |
she says . “ If you look at barnacles , for instance , |
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PHOTO : SHUTTERSTOCK |
down to make cement releases approximately a kilogram of CO 2 for every kilogram of cement made , a process responsible for 8 % of global emissions , according to a report by policy institute Chatham House .
“ It ’ s incredible when you look at what portland cement has done for us over the past 200 years of development in the growth of cities , the construction of interstate highways and high-rise towers , and so on ,” Dosier says . “ But with an estimated seven billion people set to be living in cities by 2050 , we ’ ll need to be putting up the equivalent of an entire New York City ’ s worth of buildings every single month to accommodate them .”
Given that the natural world has been making cement-like forms for hundreds of millions of years without destroying the Earth ’ s climate , Dosier wondered whether it might hold the key to helping the construction industry avert this growing environmental crisis .
“ If we don ’ t find alternatives to portland cement ,” she explains , “ if we don ’ t stop burning limestone to make concrete , then we will smother ourselves .”
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they produce one of the strongest adhesives on the planet and , if you look at their shells , those are cement-based strong and durable structures .”
The common factor , she realized — in everything from shells and coral to teeth and limestone caverns — is calcite , a hard crystalline form of calcium carbonate produced by the precipitation of calcium and carbon from the surrounding environment .
Cement manufacturers expend enormous energy to break that calcium carbonate down from limestone , only to recreate it when the cement is mixed into concrete blocks . Dosier wondered whether she could make the process more sustainable by copying how the calcite naturally formed in the first place .
In particular , she became interested in how a wide range of ground-dwelling microorganisms , such as bacteria , can extract carbon from their environment and help it to bond with surrounding calcium ions , creating cement-style calcite bonds between sand or soil particles .
Since the mid-1990s , geoengineers have been
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