The Family of cements is great. Well-known to all builders portlandtsement contains in klinkere limestone, kremnezem, alumina, okis gland - constant components. If to attach to these constant components various additives we will receive variety of versions portlandtsementa (about additives it will be in detail told and gl. "П=ѕър=ѕЁэ№х Ёрё=тюЁ№").
It is that, for example, plastifitsirovannyj portlandtsement with the additive of a concentrate sulfitno-spirit bards. It differs from usual that has the raised mobility, udoboukladyvaemost.
Waterproof portlandtsement receive, entering in klinker usual portlandtsementa at a grinding waterproof additives. Such knitting to store, transport easier - it differs the lowered hygroscopicity. To solutions gives the raised mobility, and hardened - the raised frost resistance.
Putstsolanovyj portlandtsement receive as a result of a joint grinding klinkera usual portlandtsementa with pumice, trepelom, a tufa and other active mineral additives (in number of 20... 50% of a mix). Putstsolanovyj cement apply in solutions for otdelyvanija damp premises, to external humidified surfaces.
Exist shlakoportlandtsement, glinozemistyj extending cement, white and colour portland-cements . At everyone the features, giving the chance to make reliable plaster coverings in different conditions, with the different purpose.
That year is constantly multiplied family of cements. On objects of construction engineering building, as a rule, use habitual to us, more simple cement mortals (about them is more detailed in the following chapter). And industrial targets demand absolutely other. To underline a great variety of solutions applied here on the basis of cement, I will name only some of them.
For cementation of oil and gas chinks goes belitokremnezemnyj tamponazhnyj cement - BKTS. Consists from belitovogo and vysokokremnezemnstogo components.
In mine building and at a construction of hydraulic engineering objects use bystrotverdejushchy shlakoportlandtsement raised sulfatostojkosti. its Basis - portlandtsementnyj klinker and the granulated slag.
Is vysokoglinozemistyj cement. The concrete created on its basis, depending on napolnitelej (shamot, hromit, corundum, etc.) maintains temperature 1400...1800°Р.
Come on a constant All-Union building exhibition at VDNH and you necessarily will find out at its stands booklets with the description of several more kinds of the cement created only last years. It is visible, and henceforth to grow to this nice family.
Finishing the story about knitting, let's glance as though in creation of an artificial stone. Really, unless it is not interesting to know, what for a miracle occurs to ours zhzhenymi-kalenymi, droblennymi totally powders, hardly them to give to drink water?
Here our kind acquaintance - izvest. You remember that for reception limy knitting, a natural stone-limestone burn. Thus from it carbonic gas is allocated. But here izvest have connected to water. Return chemical reaction also begins: the carbonic gas which is in air, co-operates with water, supersedes it from a solution. Izvest again gets the carbon lost at roasting and again turns to initial substance - a stone-limestone only received by an artificial way.
Such is schematic drawing of the difficult chemical reactions occurring to knitting substances at zatvorenii of them. As klinkery have various structures also chemical processes of creation of an artificial stone differently proceed. But their purpose one - to provide replacement of water and tverdenie weights of a solution.
Probably, to you will sometime have the luck to glance by means of a microscope in an inner sanctum of the transformations occurring to cement in the hardening solution. This surprising show. There inside all lives, all in movement. Here cement kashitsa obvolokla a thin film sand and others napolniteli. There passes the minute, the second - and kashitsa has begun to move, has started to swell. Needle crystals extensively began to last. They quickly fill all intervals between grains. Through certain time the birth of crystals stops, all emptiness are filled by them. Concrete is ready.
If here, the microscope, had suddenly a sample of a martin steel and you have put it under a microscope eyepiece near to concrete by all means would be amazed by obvious similarity of internal structures of these two such different materials. And after all the martin steel has a reputation, as it is known, for the firmest material. Durability of a material including our artificial stone, it is caused by a structure of its internal crystal lattice.
For all tastes, on any demand it is possible to pick up today the knitting. It is served by the whole science which is engaged in their classification, working out of recipes and "the know-how".
Builders know that all mineral knitting share on two groups: air and the hydraulic.
The First are capable to harden and keep durability only on air.
The Second harden not only on air, but also in water, long time keep durability in the water environment. Hydraulic properties of some of them can be strengthened, adding to them some natural or artificial materials - them name hydraulic additives.
The Air knitting: gipsoangidritovye and magnezialnyevjazhushchie, air izvest, soluble glass, kislotoupornyj cement.
The hydraulic knitting concern: izvest hydraulic (it hardens on air, but keeps durability in the water environment), portlandtsement, cements with hydraulic additives, slag cements, waterproof and plastifitsirovannyj cements, glinozemistyj the cement extending cement, cements for building solutions.
There is no necessity to give here in detail their components, their nobility - business of workers strojindustrii. But, it seems to me, not superfluous and shtukaturu to know, on what knitting it is necessary to apply solutions in various environments. After all we not always should work in heat and dryness.