Climate Solutions: Cement
Direct emissions from cement production were responsible for around 3% of total greenhouse gas emissions in 2016. These emissions are set to rise dramatically, with projected demand for cement ramping up rapidly in the coming decades.
Carbon dioxide is produced as a byproduct of a chemical conversion process used in the production of clinker, a component of cement. In this reaction, limestone (CaCO3) is converted to lime (CaO), and produces CO2 as a byproduct. Cement production also produces emissions from energy inputs – but these related emissions are included in ‘Energy Use in Industry’ rather than here.
Solutions in this area tackle the problem from many angles. Some initiatives aim to make concrete without cement. Others attempt to inject CO2 back into the concrete, capturing and storing it. Others aim to improve concrete's performance as a carbon sink, absorbing atmospheric carbon for many years after it's laid. This enormous problem will require many technical solutions – particularly ones that don't raise construction prices in developing countries.
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We have seen some interesting developments around what's known as self-healing concrete that repairs its own cracks, and scientists have now demonstrated an exciting new form of this that makes use of an enzyme found in human blood. -
Recent research projects have demonstrated how the wonder material graphene could play a role in stronger, more eco-friendly concrete, and now we're seeing the first real-world deployment of the technology in the foundations of a new gym in the UK.
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Researchers at the National University of Singapore have put forward a new formula for stronger concrete that not only removes a large amount of damaging materials from the equation, but makes use of upcycled waste clay at the same time.
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A six-year competition to capture CO2 emissions from operational power plants and convert them into useful products has drawn to a close, and produced dual winners with technologies that promise to reduce the environmental footprint of concrete.
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The cement used to make concrete carries quite a carbon footprint. Now, scientists at the University of Tokyo have created a cement-free alternative that directly bonds sand particles together using a reaction between alcohol and a catalyst.
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Unfortunately concrete production is a major source of carbon dioxide in the atmosphere. Now engineers at Purdue University have developed a new cement recipe that can absorb CO2 twice as fast as usual, hopefully turning it into a useful carbon sink.
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A new adaptation of a pre-stressing technique has been used to produce concrete that is lighter but with comparable strength, an advance that if widely applied, could save significant amounts of CO2.
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Strong as it is, concrete doesn’t stand up well against bending. Now, researchers at Swinburne University have developed a new type of concrete that can not only bend better, but doesn’t require cement to make, reducing its environmental footprint.
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Making cement is one of the biggest contributors of carbon emissions. Now MIT researchers have developed a new method that can clean up the process.
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To make concrete more environmentally friendly, the industry has been adding by-products from coal-fired power plants, but doing so had its own problems. Now, Rice researchers have developed a new composite binder that requires no cement, and reduce waste from power plants at the same time.
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Scientists are continually searching for greener ways of producing cement, which is an energy-intensive process. Now an MIT team has found that pulverizing volcanic ash and adding it to the mix not only makes the process more environmentally friendly, but the resulting structures stronger as well.
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As one of our most relied upon construction materials, concrete makes a significant contribution to our overall carbon emissions. By altering the quantities of materials used in this process, scientists have uncovered a method of cement mixing that could reduce these emissions by more than half.
