When you think about the resources we're running out of, sand may not be high on your list, but it is thanks to our high demand for concrete. Rice University scientists have now shown that replacing graphene can not only save sand, but also make concrete lighter, stronger and stronger.
The world faces an environmental and resource crisis due to the high dependence on concrete, the second most consumed material after water. The extraction of sand, an essential component of concrete, exceeds the natural replacement capacity, triggering serious ecological problems.
Rice University Innovation
Rice University researchers have discovered that graphene derived from metallurgical coke, a carbon-based product, could replace sand in concrete. This advancement, led by James Tour, professor of chemistry, materials science and nanoengineering, has the potential to improve the construction industry.
Benefits of graphene in concrete
Graphene concrete not only matches Phone Number List the mechanical properties of standard concrete, but also offers a higher strength-to-weight ratio. “ Our concrete is % lighter but just as resistant ,” says Tour.
Saving sand isn't the only benefit either . The resulting concrete was % lighter than concrete made with normal aggregate and showed a % increase in toughness, % in maximum strain and % in compressive strength. On the negative side, there was an % reduction in its Young's modulus, a measure of a material's resistance to stretching deformation.
Reduction of environmental impact
Concrete is made of three main ingredients: water, an aggregate like sand, and cement to hold it all together. Sand is the largest component by volume and, given modern humanity's insatiable appetite for concrete, sand extraction is increasing. This process is not only destructive, but risks running out of sources.
The production of cement, a key component of concrete, is responsible for % of global carbon dioxide emissions. Additionally, largely unregulated sand mining damages river and coastal ecosystems. The technology developed at Rice could decrease dependence on natural sand and reduce carbon emissions from the concrete industry.
Innovative Process: Joule Heating
Tour's lab has used the Joule heating technique to convert metallurgical coke into graphene. This technique produces graphene faster and on a larger scale than previous methods.
Satish Nagarajaiah, professor of civil and environmental engineering, points out that % of concrete is made up of sand . Metallurgical coke could not only improve the quality of concrete but also reduce costs significantly. However, the price of graphene still needs to be reduced for this solution to be viable on a large scale.
This study, supported by the U.S. Army Corps of Engineers, the Air Force Office of Scientific Research, and the National Science Foundation, paves the way toward more sustainable urban development practices, addressing the looming “urban crisis.” sand” and offering viable alternatives for the future of construction.