Published on April 30th, 2018 | by Steve Hanley0
Graphene Makes Concrete Stronger While Reducing Carbon Emissions
April 30th, 2018 by Steve Hanley
Concrete is one of the most widely used building materials in the world, but it also is responsible for about 5% of all global carbon dioxide emissions according to the Earth Institute at Columbia University. Those emissions result directly from the conversion of limestone into cement and indirectly by burning fuel to heat the limestone to 1400º C, the temperature required to initiate the conversion process.
“Cement manufacturing is highly energy and emissions intensive because of the extreme heat required to produce it. Producing a ton of cement requires 4.7 million BTU of energy, equivalent to about 400 pounds of coal, and generates nearly a ton of CO2. Given its high emissions and critical importance to society, cement is an obvious place to look to reduce greenhouse gas emissions,” says the Earth Institute.
Scientists at the University of Exeter have developed a pioneering new technique that uses nano-engineering technology to incorporate graphene into traditional concrete production. The resulting product is more than twice as strong and four times more water resistant than existing concrete. The graphene-reinforced concrete also greatly reduces the carbon emissions normally associated with making cement. The research was published Advanced Functional Materials last week.
Professor Monica Craciun is the co-author of the paper. She says,
“Our cities face a growing pressure from global challenges on pollution, sustainable urbanization and resilience to catastrophic natural events, amongst others. This new composite material is an absolute game-changer in terms of reinforcing traditional concrete to meets these needs. Not only is it stronger and more durable, but it is also more resistant to water, making it uniquely suitable for construction in areas which require maintenance work and are difficult to be accessed .
“Yet perhaps more importantly, by including graphene we can reduce the amount of materials required to make concrete by around 50 per cent — leading to a significant reduction of 446 kilograms per ton of the carbon emissions. This unprecedented range of functionalities and properties uncovered are an important step in encouraging a more sustainable, environmentally-friendly construction industry worldwide.”
The researchers have created a new technique that focuses on suspending atomically thin graphene in water. The process is low in cost, has few defects in the end product, and is compatible with current large scale manufacturing requirements.
Dimitar Dimov, lead author of the report, says, “This ground-breaking research is important as it can be applied to large-scale manufacturing and construction. The industry has to be modernized by incorporating not only off-site manufacturing, but innovative new materials as well.
“Finding greener ways to build is a crucial step forward in reducing carbon emissions around the world and so help protect our environment as much as possible. It is the first step, but a crucial step in the right direction to make a more sustainable construction industry for the future.”