The pozzolana is a natural Roche consisted by Scorie S (projections) volcanic basaltic or of close composition. It has a honeycomb structure. Pozzolana is generally Rouge or Noir E, with all the intermediate colors, exceptionally Gris E.

Etymology

The term “pozzolana” comes from Pouzzoles, port Italy N rich in volcanic Sable , located at the foot of the Vesuvius to the Northern of the Golfe of Naples. Ingredient essential to the development of the hydraulic Concrete whose extreme solidity and the characteristic to be able to harden under water are mainly at the origin of the power Phénicien, Greek then Roman, its secrecy was transmitted of Orient according to the Légende by the Sibylle of Cumes, Aristodémos it Malasio for the construction of Neapolis (new city) in 478 front JC.

Type of Rock

In pozzolana one finds Scorie S which indicate the depth of the magma which created it. ; Magma of surface: carboniferous Sandstone… other rocks of surface ; Intermediate magma: metamorphic Rocks ; Abyssal magma: Peridotite

Use

In garden-center

Its applications in the Jardin S are multiple:

• in gross Granulométrie it is used like Roche decorative comparable with the bark of pine;
• and into small Granulométrie it is useful in the composition of the Substrat of certain cultures like the Bonsaï or the Hydroponie. This type of rock ensures a good drainage at the level racinaire. The cutting edges of pozzolana support the development of the Radicelle S.

In construction

Pozzolana is at the base of the manufacture of some Ciment S.

The Tuf constituting the basement of Rome is composed of two types of volcanic rocks:

• the Pépérin, solid and similar to the stone,
• pozzolana, friable and sandy, suitable to compose tough cement, main cause of the duration of the Roman monuments.

Used in the Breeze block S, it was also used when designing ground of the Stade de France: pozzolana, very porous, makes it possible water to run out and evacuate very quickly the Pelouse.

Generally, this construction materials is lighter than different, standard materials silico calcareous: in public works, that makes it possible to implement embankments barges: too weak ground to receive a road, fill on work undergrounds… The average density of pozzolana once in place turns around 1,5 T/m3 instead of 1,9 T/m3 for traditional materials.

On the roads

Pozzolana is also widespread in Hiver on the Route S where the Froid is such as the salt is ineffective. Failing to dissolve the Snow and the Ice, that makes it possible to maintain enough good conditions of Adhérence for the Véhicule S.

Localization

One finds pozzolana in any volcanic area. In France one finds pozzolana in a natural state in Auvergne. The Cape Verde (volcanic island with broad of the Senegal) also produced pozzolana, via the Cabocem company.

One also finds some in store of Bricolage.

See too

• Pounce

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