Cement

views updated Jun 11 2018

CEMENT

CEMENT. In Newly discovered lands, adventurers seek gold, while colonists seek limestone to make cement. American colonists made their first dwellings of logs, with chimneys plastered and caulked outside with mud or clay. To replace these early homes, the first bricks were imported. Brick masonry requires mortar; mortar requires cement.

Cement was first made of lime burned from oyster shells. In 1662 limestone was found at Providence, Rhode Island, and manufacture of "stone" lime began. Not until 1791 did John Smeaton, an English engineer, establish the fact that argillaceous (silica and alumina) impurity gave lime improved cementing value. Burning such limestones made hydraulic lime—a cement that hardens under water.

Only after the beginning of the country's first major public works, the Erie Canal in 1817, did American engineers learn to make and use a true hydraulic cement (one that had to be pulverized after burning in order to slake, or react with water). The first masonry on the Erie Canal was contracted to be done with common quick lime; when it failed to slake a local experimenter pulverized some and discovered a "natural" cement, that is, one made from natural rock. Canvass White, subsequently chief engineer of the Erie Canal, pursued investigations, perfected manufacture and use, obtained a patent, and is credited with being the father of the American cement industry. During the canal and later railway building era, demand rapidly increased and suitable cement rocks were discovered in many localities.

Cement made at Rosendale, New York, was the most famous, but that made at Coplay, Pennsylvania, the most significant, because it became the first American Portland cement. Portland cement, made by burning and pulverizing briquets of an artificial mixture of limestone (chalk) and clay, was so named because the hardened cement resembled a well-known building stone from the Isle of Portland. Soon after the Civil War, Portland cements, because of their more dependable qualities, began to be imported. Manufacture was started at Coplay, Pennsylvania, about 1870, by David O. Saylor, by selecting from his natural cement rock that was approximately of the same composition as the Portland cement artificial mixture. The Lehigh Valley around Coplay contained many similar deposits, and until 1907 this locality annually produced at least half of all the cement made in the United States. By 1900 the practice of grinding together ordinary limestone and clay, burning or calcining the mixture in rotary kilns, and pulverizing the burned clinker had become so well known that the Portland cement industry spread rapidly to all parts of the country. There were 174 plants across the country by 1971. Production increased from 350,000 barrels in 1890 to 410 million barrels in 1971.

At first cement was used only for mortar in brick and stone masonry. Gradually mixtures of cement, sand, stone, or gravel (aggregates) with water (known as concrete), poured into temporary forms where it hardened into a kind of conglomerate rock, came to be substituted for brick and stone, particularly for massive work like bridge abutments, piers, dams, and foundations.

BIBLIOGRAPHY

Andrews, Gregg. City of Dust: A Cement Company in the Land of Tom Sawyer. Columbia: University of Missouri Press, 1996.

Hadley, Earl J. The Magic Powder: History of the Universal Atlas Cement Company and the Cement Industry. New York: Putnam, 1945.

Lesley, Robert W. History of the Portland Cement Industry in the United States. Chicago: International Trade, 1924.

Nathan C.Rockwood/t. d.

See alsoBuilding Materials ; Housing .

cement

views updated Jun 08 2018

ce·ment / siˈment/ • n. a powdery substance made by calcining lime and clay, mixed with water to form mortar or mixed with sand, gravel, and water to make concrete. ∎  a soft glue that hardens on setting: rubber cement. ∎ fig. an element that unites a group of people. ∎ another term for concrete. ∎  a substance for filling cavities in teeth. ∎  (also cementum) Anat. a thin layer of bony material that fixes teeth to the jaw. ∎ Geol. the material that binds particles together in sedimentary rock.• v. [tr.] attach with cement: wooden posts were cemented into the ground. ∎ fig. settle or establish firmly: the two firms are expected to cement an agreement soon. ∎  Geol. (of a material) bind (particles) together in sedimentary rock.DERIVATIVES: ce·ment·er n.

cement

views updated May 23 2018

cement.
1. Substance to bind together the materials in concrete, mortar, etc., hardening it to a solid.

2. Render used to provide a finish to external walls, also called stucco. C18 types of cement-render included Liardet's Cement (which included oil), extensively used by the Adam Brothers, but it did not last, and fell off. More satisfactory was Parker's (also called Roman or Sheppey) Cement, discovered in 1796, which was widely used by Nash and his contemporaries, but it was a dark brown colour, so was sometimes called black cement: it did have one great advantage, however, in that it was waterproof. Atkinson's Cement, also called Yorkshire or Mulgrave Cement, was a better, lighter colour than Roman Cement, but was inclined to shrink and crack unless plenty of sand was used in the mix. Portland Cement, discovered by Joseph Aspdin (1779–1855) in 1794 and patented by him in 1824, was also widely used as a render, but again it had to be very weak and mixed with plenty of sand otherwise it cracked.

Bibliography

N. Davey (1961);
Gwilt (1903);
W. Papworth (1853–92)

cement

views updated May 08 2018

cement
1. Manufactured powder made from limestone and clay which sets to a solid mass when mixed with water. Commercial cements have to fulfil certain defined standards. Combined with aggregate it forms concrete.

2. Material, e.g. calcite, that fills open pore space in fragmental and organic sediments.

Cement

views updated Jun 11 2018

Cement ★★½ 1999 (R)

Intense performances in a nasty crime story told via flashbacks. Hollywood vice detectives Holt (Penn) and Nin (Wright) have crossed the line between the cops and the criminals. When violent Holt catches his gal (Fenn) with a local wiseguy (DeSando), he buries him in a cement freeway and the mob is out for revenge. Pasdar's directorial debut. 100m/C VHS, DVD . Christopher Penn, Jeffrey Wright, Sherilyn Fenn, Anthony De Sando, Henry Czerny; D: Adrian Pasdar; W: Justin Monjo; C: Geary McLeod; M: Doug Caldwell.

cement

views updated May 09 2018

cement (cementum) A thin layer of bony material that fixes teeth to the jaw. It covers the dentine of the root of a tooth, below the level of the gum, and is attached to the periodontal membrane lining the tooth socket in the jawbone.

cement

views updated May 18 2018

cement sb. XIII. ME. siment — (O)F. ciment :- L. cæmentum quarry stone, pl. chips of stone, f. *cædmentum, f. cædere hew; see -MENT.
So as vb. XIV. — (O)F. cimenter.

cement

views updated May 21 2018

cement (si-ment) n.
1. any of a group of materials used in dentistry either as fillings or as lutes for crowns.

2. see cementum.

cement

views updated May 29 2018

cement A bone-like substance which coats the surface of that part of a tooth which is embedded in the jaw and which sometimes coats the enamel of the exposed part of the tooth.

cement

views updated May 14 2018

cement A bone-like substance which coats the surface of that part of a tooth which is embedded in the jaw and which sometimes coats the enamel of the exposed part of the tooth.