| Concrete is the most widely used manmade product | | | | ecological sustainability and environmental damage.The |
| in the world. It powers a $35 billion industry, one of | | | | composition of concrete is traditionally relatively |
| the largest on Earth. Concrete is used to make a | | | | simple. However, modern concrete is often a |
| variety of structures a which you use | | | | complicated mix, ensuring durability and longevity. |
| everyday.Concrete is a construction material that | | | | Cement is the main ingredient in concrete. Portland |
| consists of, in its most common form, cement, gravel | | | | cement is the most common cement in circulation, |
| and sand, and water. Concrete is the most highly | | | | which is just a basic mix of mortar and plaster.Water |
| used manmade product on Earth. It is used to make | | | | is another ingredient in the manufacture of concrete. |
| pavements, building structures, foundations, | | | | The w/c ratio (mass ratio of water to cement) is the |
| motorways/roads, overpasses, parking structures, | | | | key factor that determines the strength of Concrete. |
| brick/block walls and | | | | A lower w/c ratio will yield a concrete which is |
| footings for gates, fences and poles. Approximately | | | | stronger, while a higher w/c ratio yields a concrete |
| six billion cubic metres of concrete are produced | | | | with a lower strength. Water also affects the |
| every year, which is one cubic metre per person on | | | | workability and consistency of a concrete.This water |
| Earth! Concrete commands a $35 billion worldwide | | | | and cement paste hardens over time, and both fine |
| industry and employs, in the United States alone, 2 | | | | and coarse aggregates are added to provide bulk. |
| million people.The origins of concrete can be traced | | | | Widely used aggregates include sand, gravel and |
| back to the Babylonians, who used a clay-mix similar | | | | crushed stone. Decorative stones such as, small river |
| to concrete. However, the modern-day form of | | | | stones or crushed glass are sometimes added to the |
| concrete was not invented till 1756, when British | | | | surface of concrete for a decorative "exposed |
| engineer John Smeaton pioneered the use of cement | | | | aggregate" finish, popular among landscape |
| in concrete. His ingredients included pebbles and | | | | designers.Ad mixtures are also added to a concrete |
| powdered brick as | | | | mix to give it certain characteristics not obtainable by |
| aggregate. Nowadays, recycled materials are | | | | basic production. Admixtures come in powder or |
| becoming increasingly more popular as ingredients in | | | | paste form and generally consist of no more than |
| concrete due to higher public awareness about | | | | 5% of the entire mixture. |