In the most general sense of the word, a cement is a binder, a substance that sets and hardens independently, and can bind other materials together. The word "cement" traces to the Romans, who used the term opus caementicium to describe masonry resembling modern concrete that was made from crushed rock with burnt lime as binder. The volcanic ash and pulverized brick additives that were added to the burnt lime to obtain a hydraulic binder were later referred to as cementum, cimentum, cäment, and cement.

Cement used in construction is characterized as hydraulic or non-hydraulic. Hydraulic cements (e.g., Portland cement) harden because of hydration, chemical reactions that occur independently of the mixture's water content; they can harden even underwater or when constantly exposed to wet weather. The chemical reaction that results when the anhydrous cement powder is mixed with water produces hydrates that are not water-soluble. Non-hydraulic cements (e.g. gypsum plaster) must be kept dry in order to retain their strength.

The most important use of cement is the production of mortar and concrete—the bonding of natural or artificial aggregates to form a strong building material that is durable in the face of normal environmental effects.

Concrete should not be confused with cement, because the term cement refers to the material used to bind the aggregate materials of concrete. Concrete is a combination of a cement and aggregate.

Read more about Cement:  Curing (Setting), Safety Issues, Cement Industry in The World, Environmental Impacts, Green Cement

Other articles related to "cement":

Lehigh Permanente Quarry - Pollution - Mercury Emissions
... The cement plant at the quarry has been fueled by petroleum coke since 2007, the latter (along with the limestone itself) is a major source of mercury ... The cement plant is responsible for 29% of total Bay Area airborne mercury emissions and was shown to impact a rural site, Calero Reservoir, 20 miles (32 km) away ... web, was found to be 5.8 to 6.7 times higher in precipitation near the cement plant than at a control location 2.0 miles (3.2 km) away ...
Lucky Cement
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List Of Countries By Cement Production
... This is a list of top countries by cement production in 2011 based on USGS Mineral Program Cement Report ... All top European cement producing countries except Turkey lost their rankings (Spain, Italy, Germany and France), as a result of the global financial crisis ... World Cement production in 2011e Rank Country/Region mil Tonnes 1 People's Republic of China 2,000 2 India 3 ... Iran 72 4 United States 68.4 5 Turkey 64 6 ...
Snyder Estate Natural Cement Historic District - Significant Contributing Properties - Century House
... The house features the Cement Industry Museum, with artifacts and photographs from the Rosendale cement industry ... Rosendale Natural Cement was used in the building of many historic buildings and structures, including the Brooklyn Bridge, the pedestal of the Statue of Liberty, the wings of the U ...
Lehigh Permanente Quarry - History
... Kaiser as the Kaiser Permanente Cement Plant in 1939, taking the name of the business from the Permanente Creek in whose valley it lies ... Kaiser intended to use the quarry to provide the majority of the cement used in the construction of the Shasta Dam, supplying the 6 million barrels (950,000 m3) of cement ... The cement plant is the sole reason for the lone railroad line that runs through the city ...

Famous quotes containing the word cement:

    Between married persons, the cement of friendship is by the laws supposed so strong as to abolish all division of possessions: and has often, in reality, the force ascribed to it.

    David Hume (1711–1776)

    It is fair to assume that when women in the past have achieved even a second or third place in the ranks of genius they have shown far more native ability than men have needed to reach the same eminence. Not excused from the more general duties that constitute the cement of society, most women of talent have had but one hand free with which to work out their ideal conceptions.
    Anna Garlin Spencer (1851–1931)