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Pozzolana From Wikipedia, the free encyclopedia Jump to: navigation, oceanrch Pozzolana, also know as pozzolanic change (pulvis puteolanus in Latin), is a siliceous or siliceous and aluminous material which reacts with calcium hydroxide in the front of pee at room temperature (cf. pozzolanic chemical reaction). In this reaction water-insoluble calcium silicate hydrate and calcium aluminate hydrate compounds are unionise possessing cementitious properties. The designation pozzolana is derived from one of the primary deposits of volcanic ash utilise by the Romans in Italy, at Pozzuoli. Nowadays the rendering of pozzolana encompasses any volcanic material (pumice or volcanic ash), preponderantly composed of fine volcanic glass, that is used as a pozzolan. Note the difference with the term pozzolan, which exerts no bearing on the specific origin of the material, as opposed to pozzolana, which can to date be used for pozzolans of volcanic origin, primarily composed of volc anic glass. Historical use Pozzolanas such as Santorin earth were used in the Eastern Mediterranean since 500-400 BC. Although pioneered by the ancient Greeks, it was the Romans that heretoforetu whollyy satisfy developed the potential of spread out-pozzolan pastes as binder level in Roman concrete used for buildings and underwater construction.

Vitruvius speaks of foursome types of pozzolana: black, white, grey, and red, all of which can be found in the volcanic areas of Italy, such as Naples. Typically it was very thoroughly commingle two-to-one with lime just prior to mixing with water. The Roman fashion at Cosa was built of p ozzolana-lime concrete that was poured under! water, apparently using a persistent tube to carefully lay it up without allowing sea water to mix with it. The three piers are still panoptic today, with the underwater portions in generally excellent condition even afterwards more than 2100 years. Geochemistry and mineralogy The major pozzolanically active component of volcanic pumices and ashes is a highly porous glass.[1] The easily...If you want to get a full essay, order it on our website: BestEssayCheap.com

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