VACANCY VAUCLUSIAN SPRING

VACANCY Lacune

Defects

Absence in a structure of one or several elements (example: quarry stone wrenching). Syn. with HOLE

VACUOLAR DOLOMITE LIMESTONE Cargneule

Geology

Syn. with AMYGDALOIDAL ZECHSTEIN DOLOMITE; BLASENSCHIEFER

VACUOLAR ROCK Roche vacuolaire

Geology

An eruptive rock of volcanic origin with many pores, spherical bubbles resulting from the solidification of a gas-rich magma. Cavernous grit stone, pumice, volcanic scoria, and some lava are vacuolar rocks.

VACUOLE Vacuole

Geology

A type of small bubble affecting the internal structure of certain solid rocks.

VACUUM CLEANING D poussi rage

Building Materials

A coarse method of grain-size classification eliminating the thinnest particles from fractions less thin.

VACUUM CONCRETE B ton essor par le vide; B ton sous vide

Building Materials

A material that contains at the beginning a deliberate water excess so as to obtain an excellent workability. In order to prevent an excess water from affecting the definitive strength of the work, one pulls this water out of the concrete under vacuum. For this reason, one pours the concrete in formworks with a perforated face so that the excess water is extracted by suction through the perforations by means a vacuum pump. The effect of vacuum is to evacuate the excess water and the intervals left by the water disappear thanks to atmospheric pressure. This process leads to a strong cohesion of the concrete enabling a rapid form striking. Syn. with VACUUM DEWATERING

VACUUM DEPOSIT D p t sous vide

Metallurgy

A coating obtained by displacement of a filler metal by vacuum; the operating procedure can...