Cement

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Cement_Garden,_The :: Cement_City :: Cement :: Cement_Testing :: Cementitious_Decks,_Underlayment

Cement is a material used for bonding other materials together, and as a binder in concrete. The term cement is most commonly used to refer more specifically to powdered materials which develop strong adhesive qualities when combined with water. These materials are more properly known as hydraulic cements. Portland cement is by far the most common and most important hydraulic cement in modern construction. Gypsum plaster and common lime are not hydraulic cements. Concrete is comprised of cement, mineral aggregate (gravel and sand), and other minor additives. Mortar is primarily composed of cement, lime, and sand. Grout is comprised of cement, and water, and sometimes contains fine sand and other additives.

Portland cement is made primarily from limestone, certain clay minerals, and gypsum, in a process that drives off carbonates and chemically alters the composition of the primary ingredients.

Other types

Slag cement is a hydraulic made using blast furnace slag which is a by product from iron making, with properties similar to portland cement.

Geopolymer cements are hydraulic cements using other mineral sources to obtain special properties.

History

Hydraulic cement was first invented by the Egyptians, and later reinvented by the Greeks and Babylonians, who made their mortar out of lime, much harder than the Roman mortars. Later, the Romans produced a good cement from pozzolanic ash.

Other civilizations that had a similar material to cement were the Aztecs.

Portland cement was patented in England by Joseph Aspdin in 1824.

Geology

In geology, the term is used to refer to the fine-grained minerals which bind the coarser-grained matrix in sedimentary rocks. Such cements are typically composed of calcite, quartz or clay minerals.

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Other types

History

Geology

See also