Portland cement

or portland cementn. A hydraulic cement made by heating a limestone and clay mixture in a kiln and pulverizing the resulting material.

[After Portland, an urban district of southern England.]

Portland cement

n (Building) a cement that hardens under water and is made by heating a slurry of clay and crushed chalk or limestone to clinker in a kiln [C19: named after the Isle of Portland, because its colour resembles that of the stone quarried there]

Port′land cement′

n. a type of hydraulic cement usu. made by burning a mixture of limestone and clay in a kiln. [1815–25; after the Isle of Portland, Dorsetshire, England]

Thesaurus

Noun

Portland cement - a cement that hardens under water; made by heating limestone and clay in a kiln and pulverizing the resulthydraulic cementcement - a building material that is a powder made of a mixture of calcined limestone and clay; used with water and sand or gravel to make concrete and mortar

Portland Cement

portland cement

[′pȯrt·lənd si′ment] (materials) A hydraulic cement made of pulverized, calcined argillaceous and calcareous materials; the proper name for ordinary cement.

Portland cement

Building material made from limestone, gypsum, and shale or clay that, when mixed with water, binds sand and gravel into concrete. Portland cement was invented in 1824 by Joseph Aspdin, a British stone mason, who named it after a natural stone quarried on the Isle of Portland off the British coast.

Portland Cement

a hydraulic binder composed chiefly of calcium silicates. The most widely used cement in modern construction, Portland cement is obtained by pulverizing clinker with gypsum (3–7 percent); active mineral additives (10–15 percent) may be added to the mixture. Clinker is produced upon calcination (to the point of complete sintering) of an artificial mixture of raw materials containing approximately 75 percent calcium carbonate, usually limestone, and 25 percent clay. The raw material is generally calcined in rotary kilns at 1450°-1500°C.

The properties of portland cement depend mainly on the clinker composition and on the degree to which the clinker is pulverized. The most important property of portland cement is its ability to harden upon interaction with water. This property is reflected in the grade of portland cement, which is determined by the compressive and bending (tensile) strengths of standard specimens made from a sand-cement solution after a 28-day setting period under humid conditions; grades of portland cement from 300 to 600 have been established in the USSR.

In addition to ordinary portland cement, other varieties are produced, which differ in composition, properties, and use. They include quick-setting, plastic, hydrophobic, sulfate-resistant and white portland cements, as well as a special type for use in the manufacture of asbestos-cement articles.

REFERENCES

Volzhenskii, A. V., Iu. S. Burov, and V. S. Kolokol’nikov. Mineral’nye viazhushchie veskchestva, 2nd ed. Moscow, 1973.

K. N. POPOV

portland cement

A cementitious binder used in most modern structural concrete; manufactured by grinding and burning a mixture of limestone with clay or shale with a small amount of gypsum. It is mixed with water and an aggregate (such as sand and/or gravel) to form a thick, heavy liquid that dries as a monolithic product. Although cement was developed by the ancient Romans, portland cement was first developed in England in 1824; since then, its tensile strength has greatly increased.

Portland cement

Portland cement

Portland cement

Port′land cement′

Portland Cement

portland cement

Portland cement

Portland Cement

REFERENCES

portland cement

Portland cement

Synonyms for Portland cement

noun a cement that hardens under water

Synonyms

Related Words