| you are: Properties of pottery
Mark on frost resistance is designated by number of cycles of alternate freezing and thawing which stands a product in the conditions of standard test without any signs of visible damages (stratification, a peeling, rastreskivanie, vykrashivanie). ООО "СкБетон". город и область забетонируем полы выгодно продукт сертефицирован Бетон. According to Ampere-second researches. Berkmana and And. G.Melnikovoj a ceramic material is cold-resistant, if in it the volume of reserve time Vp is sufficient for indemnification of a gain of volume of freezing water in a dangerous time. This condition have expressed in the form of the formula for calculation of the structural characteristic of a material.
A large time concerns the reserve (diameter more than 200 microns) in which capillary pressure is not enough for water deduction. A dangerous time (diameter 200 microns and less) keeps the water freezing at temperature from-15 to-20В°S.
The Ordinary clay brick is cold-resistant at G9%.
Paropronitsaemost stenovyh pottery promotes natural ventilation of premises. Small paropronitsaemost quite often serves as the reason otpotevanija to an internal surface of walls of premises with the raised humidity of air. Paropronitsaemost depends on porosity and character of a time. For example, factor paropronitsaemosti front tiles of moist pressing with water absorption 8,5; 6,5 and 0,25% it is accordingly equal 0,155; 0,0525 and 0,029 g (m-m-pas). Unequal paropronitsaemost layers of which the external wall consists, causes moisture accumulation. So, front facing of walls glazurovannymi tiles can lead to moisture accumulation in a contact layer a wall - a tile, the subsequent freezing of a moisture causes otsloenie facings.
|
