| you are: Porosity of a cement stone
Durability in the subsequent terms tverdenija (after 7 sut) is caused by hydration of an internal part of grains of larger fractions of cement.
Frost resistance depends on mineral structure klinkera, material structure portlandtsementa and capillary porosity of a cement stone. The quantity trehkaltsievogo aluminate is limited by 5-7%. Additives of a sedimentary origin (diatomit, trepel) increase water requirement of concrete mixes and lower frost resistance. To frost resistance increase apply additives of surface-active substances. Покупаете квартиры? Зайди на сайт застройщика - Купить квартиру в Краснодаре
Unlike durability frost resistance of a cement stone is defined not by the general, and capillary porosity. A capillary time lowers frost resistance, therefore their volume is limited depending on concrete mark on frost resistance.
Vozduhostojkost - ability of a cement stone to keep durability in dry conditions, at strong heating by solar beams, and also in the conditions of alternate humidifying and drying. The cements containing active mineral additives of a sedimentary origin, not only are less cold-resistant, but also less vozduhostojki. It speaks mainly degidratatsiej (aeration) of a part of water from nizkoosnovnyh hydrosilicates of calcium which were formed at interaction of amorphous dioxide of silicon with hydrate okisi calcium. Therefore, for example, putstsolano-vyj portlandtsement it is recommended to apply in damp conditions, to underwater and underground designs.
Chemical firmness. Corrosion is caused by influence of aggressive gases and liquids on components hardened portlandtsementa. There are tens the substances, able to influence a cement stone and to appear for it harmful.
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