Concrete
The formula for making concrete is simple. And the ingredients required are easy to obtain: ce ment is made with limestone and clay, gravel or sand and water. Stirring these materials together produces a wet mixture that can be formed into any shape – and is incredibly strong and fireproof once it has hardened. This makes concrete an ideal building mate rial: seven out of every ten people in the world live in buildings constructed using concrete. And it will continue to be an indis pensable building material in future. For this reason, efforts are underway to make concrete production more eco-friendly and, consequently, sustainable. A circular economy approach is already being adopted too: this involves crushing demolition concrete, removing any foreign material and then sorting it ac cording to particle size. It is then added to fresh concrete as aggregate.
24
Powered by FlippingBook