Green concrete was 1st invented in Denmark in 1998. It is a friendly environmentally concrete which is produced using a mixture of non-CO2 production method or it is concrete which utilizes waste materials as at least one of its ingredients. The production process of green concrete does not lead to environmental destruction.
The word green in green concrete is not just limited to color. The green color represents the environment. It is environmentally friendly concrete. This concrete follows the techniques of reuse-reduce-recycle. Green concrete reduces greenhouse gas emission.
This concrete is made to waste concrete materials and uses less energy in its production and produces less carbon dioxide than normal concrete. The cement used in green concrete consists of limestone (calcium carbonate CaCO3). During manufacture, the ingredients of cement are heated to about 800 to 10000-degree centigrade. Carbon dioxide is driven off during the manufacturing process of cement.
Aggregates are the main ingredient in concrete. Due to consistently mining the availability of aggregates have emerged problem in recent time. There is a solution to find some extent and the solution is known as green concrete. For each ton of cement produced about 0.9 tons of carbon dioxide is produced. CO2 is the greenhouse gas which is responsible for global warming.
Materials for Green Concrete:
Fly ash and eco-cement
Fly ash aggregates
Reused demolition waste aggregates
Reused or recycled concrete aggregates
(BFS) blast furnace slag
Rice husk ash: it is hard protecting covering the grains of rice.
Concrete mix design method for green concrete is similar to conventional concrete.
The cement and aggregates used in this concrete must pack themselves in such a manner that they occupy minimum volume or giving the minimum number of voids in concrete.
The ingredients used in this concrete contains large voids.
For achieving an impervious or dense concrete then all voids should be packed with smaller particles of next type of material.