Hydraulic cement: Difference between revisions
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== Description == | == Description == | ||
A calcium-containing [[cement]] that reacts with water to harden, even without drying. Hydraulic cements composed of [[lime]] and volcanic ash ([[pozzolana]]) were first used in ancient Greece and Rome. The mixture must contain at least 12% of a silicate/aluminate component such as [[clay]], [[calcium silicate]] ([[portland cement]]), [[calcium aluminate]], [[oxychloride cement|magnesium oxychloride]], [[pozzolana]], [[slag]], barium silicate/barium aluminate, brick dust, volcanic ash, [[pumice]], etc. These may be present as original components in the burnt limestone or as additives. In water, the lime mixture hardens to a water resistant solid due to complex exothermic chemical changes involving the hydration of calcium silicates and aluminates. | A calcium-containing [[cement]] that reacts with water to harden, even without drying, into a water-resistant solid. Hydraulic cements composed of [[lime]] and volcanic ash ([[pozzolana]]) were first used in ancient Greece and Rome. The mixture must contain at least 12% of a silicate/aluminate component such as [[clay]], [[calcium silicate]] ([[portland cement]]), [[calcium aluminate]], [[oxychloride cement|magnesium oxychloride]], [[pozzolana]], [[slag]], barium silicate/barium aluminate, brick dust, volcanic ash, [[pumice]], etc. These may be present as original components in the burnt limestone or as additives. In water, the lime mixture hardens to a water resistant solid due to complex exothermic chemical changes involving the hydration of calcium silicates and aluminates. | ||
Examples are: [[Roman cement]], and [[portland cement]]. | Examples are: [[Roman cement]], and [[portland cement]]. | ||
Latest revision as of 10:41, 18 March 2025
Description
A calcium-containing cement that reacts with water to harden, even without drying, into a water-resistant solid. Hydraulic cements composed of lime and volcanic ash (pozzolana) were first used in ancient Greece and Rome. The mixture must contain at least 12% of a silicate/aluminate component such as clay, calcium silicate (portland cement), calcium aluminate, magnesium oxychloride, pozzolana, slag, barium silicate/barium aluminate, brick dust, volcanic ash, pumice, etc. These may be present as original components in the burnt limestone or as additives. In water, the lime mixture hardens to a water resistant solid due to complex exothermic chemical changes involving the hydration of calcium silicates and aluminates.
Examples are: Roman cement, and portland cement.
Synonyms and Related Terms
ciment hydraulique (Fr.); cimento hidráulico (Port.); water cement; water lime; Roman cement; portland cement; Rosendale cement; slate cement; hydraulic lime; pozzolana
Risks
- Reaction with water may be exothermic
Resources and Citations
- J.H.Wills, "Inorganic Adhesives and Cements" in Handbook of Adhesives, I.Skeist (ed.), Van Nostrand Reinhold, New York, 1977. p.117-138.
- John Ashurst "The Technology and Use of Hydraulic Lime" Building Conservation Directory 1997: Link -(contains specifications and characteristics of different mixture compositions)
- R. J. Gettens, G.L. Stout, Painting Materials, A Short Encyclopaedia, Dover Publications, New York, 1966
- Thomas Gregory, The Condensed Chemical Dictionary, Reinhold Publishing, New York, 3rd ed., 1942
- Susan E. Schur, Conservation Terminology: A review of Past & Current Nomenclature of Materials, Technology and Conservation, Spring (p.34-39); Summer (p.35-38); Fall (p.25-36), 1985
- Dictionary of Building Preservation, Ward Bucher, ed., John Wiley & Sons, Inc., New York City, 1996
- Wikipedia: Cement Accessed March 2025