Good news! Amazing stuff! The many uses of graphene!
"... Scientists at Rice University have now shown that substituting graphene can not only save sand, but makes concrete lighter, stronger and tougher. ...
making graphene for years using a technique they developed called flash Joule heating. Essentially, a carbon-rich base material is quickly superheated with a zap of electricity, converting it into graphene flakes. In this case, the base material was metallurgical coke, a fuel source created from coal. ...
While the team says graphene is currently too expensive to make this method commercially viable at scale, it at least shows that there are alternatives that could be pursued."
While the team says graphene is currently too expensive to make this method commercially viable at scale, it at least shows that there are alternatives that could be pursued."
"The world’s reliance on concrete, the second most consumed material after water, is leading to an environmental and resource crisis, with sand mining rates outstripping natural replenishment.
A study by Rice University researchers found that graphene derived from metallurgical coke, a coal-based product, could serve not only as a reinforcing additive in cement but also as a replacement for sand in concrete. ..."
From the abstract:
"Each year, the growth of cities across developing economies in Asia, Africa, and Latin America drives demand for concrete to house and serve their burgeoning populations. Since 1950, the number of people living in urban areas has quadrupled to 4.2 billion, with another predicted 2.5 billion expected to join them in the next three decades. The largest component of concrete by volume is aggregates, such as sand and rocks, with sand as the most mined material in the world. However, the extraction rate of sand currently exceeds its natural replenishment rate, meaning that a global concrete-suitable sand shortage is extremely likely. As such, replacements for fine aggregates, such as sand, are in demand. Here, flash Joule heating (FJH) is used to convert coal-derived metallurgical coke (MC) into flash graphene aggregate (FGA), a blend of MC-derived flash graphene (MCFG), which mimics a natural aggregate (NA) in size. While graphene and graphene oxide have previously been used as reinforcing additives to concrete, in this contribution, FGA is used as a total aggregate replacement for NA, resulting in 25% lighter concrete with increases in toughness, peak strain, and specific compressive strength of 32, 33, and 21%, respectively, with a small reduction in specific Young’s modulus of 11%. FJH can potentially enable the replacement of fine NA with FGA, resulting in lighter, stronger concrete."
Rice study shows coal-based product could replace sand in concrete Discovery could be part of a solution to the looming ‘sand crisis’
Replacement of Concrete Aggregates with Coal-Derived Flash Graphene (no public access)
No comments:
Post a Comment