Cement

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Avatar for Ajadiken
4 years ago

cement is a binder, a substance used for construction that sets, hardens, and adheres to other materials to bind them together. Cement is seldom used on its own, but rather to bind sand and gravel (aggregate) together. Cement mixed with fine aggregate produces mortar for masonry, or with sand and gravel, produces concrete. Concrete is the most widely used material in existence and is only behind water as the planet's most-consumed resource.[3]

Cements used in construction are usually inorganic, often lime or calcium silicatebased, which can be characterized as non-hydraulic or hydraulic respectively, depending on the ability of the cement to set in the presence of water (see hydraulic and non-hydraulic lime plaster).

Non-hydraulic cement does not set in wet conditions or under water. Rather, it sets as it dries and reacts with carbon dioxide in the air. It is resistant to attack by chemicals after setting.

Hydraulic cements (e.g., Portland cement) set and become adhesive due to a chemical reaction between the dry ingredients and water. The chemical reaction results in mineral hydrates that are not very water-soluble and so are quite durable in water and safe from chemical attack. This allows setting in wet conditions or under water and further protects the hardened material from chemical attack. The chemical process for hydraulic cement was found by ancient Romans who used volcanic ash (pozzolana) with added lime (calcium oxide).

The word "cement" can be traced back to the Roman term opus caementicium, used to describe masonry resembling modern concrete that was made from crushed rock with burnt lime as binder. The volcanic ash and pulverized brick supplements that were added to the burnt lime, to obtain a hydraulic binder, were later referred to as cementumcimentumcäment, and cement. In modern times, organic polymers are sometimes used as cements in concrete.

If the cement industry were a country, it would be the third largest carbon dioxide emitter in the world with up to 2.8bn tonnes, surpassed only by China and the US.[4]

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Comments

Nice Check on me n sub back

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4 years ago

This is interesting. Check on me and sub bck

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4 years ago

Thanks brother Done

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4 years ago

Good info...

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4 years ago

Thanks brother

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4 years ago

Awwn, great content

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4 years ago

Thanks brother

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4 years ago

Good one brother

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4 years ago

Thanks eje

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4 years ago

Orire wa níbẹ

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4 years ago

So informative, thanks.

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4 years ago

Thanks boss

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4 years ago

Smiles

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4 years ago