By Construction Tech Review | Wednesday, June 12, 2019
FREMONT, CA: Green concrete is vital from the environmental perspective, and the construction industry should encourage its usage.
Cement is one of the core constituents of concrete, and it lends the binding ability to it. The manufacturing process of cement is a matter of concern as it contributes almost 7 percent annually to CO2 emissions. Sustainability in production and manufacturing industries has become increasingly important these days, and hence, stakeholders are working towards solutions that would make concrete environmental friendly.
The manufacturing process of cement involves grinding and heating the raw materials. Fossil fuels are burnt to heat the mixture to very high temperatures, which leads to CO2 generation. The process of calcination also contributes to the CO2 produced. In order to reduce CO2 production, one must reduce the amount of cement that one needs for strong and durable concrete. This can be achieved by incorporating other substances that can enhance the properties of concrete, thereby reducing the dependence on cement.
Researchers have been conducting experiments that have given good results. One such research involved the use of graphene, which is a form of carbon which is present as single layers and has atoms arranged in a hexagonal lattice. It is a semi-metal with a host of desirable properties. The best property from the concrete point of view is its strength, which is two hundred times that of steel. Graphene is incorporated, into concrete by suspending graphene sheets into the water that is used in mixing the concrete. The researchers found this concrete to have double the strength and four times the water resistance of conventional concrete.
In another instance, researchers used the nanoplatelets derived from the fibers of root vegetables and added it to the Portland cement. This led to an increase in the amount of calcium silicate hydrate and enhanced strength of concrete apart from making it durable. Scientists have also devised a way to make concrete using fly ash which does not require heating or addition of cement at all. Fly ash molecule is modified by rearranging the atoms and then it is combined with sodium silicate and calcium oxide to create a porous inorganic polymer.