Cement represents the parent material used in the sphere of construction. Substance in the form of powder is dissolved by liquid therefore dense weight is formed. When hardening, cement changes the players and turns into the material on durabilities reminding stone. History of cement contains set of centuries. Its players were repeatedly changed. At the moment there are several its versions.
Cement history
It is considered that Romans became the first inventors of cement. For production of construction mix they used lime to which volcanic ash and the crushed hardened deposits were mixed in certain proportions.
Numerous study and the experiments made by masters have led to the fact that cement began to be done of special kind of lime and clay. The main properties of these components of construction material are partial melting when heating and quite fast process of "petrifaction".
For several years there was such kind of cement as romantsement, however at the moment its production is suspended.
Types of cement
Depending on structure distinguish several types of cement, each of which is applied to the certain sphere of construction. Portland cement is considered the most widespread. Almost for 80% this cement consists of calcium silicates. Instead of lime by production of this material the limy product – clinker is used. The second main component in this structure is plaster. Portland cement is made in dry or liquid look. Magnesia cement – construction material which part oxides and salts of magnesium are. Such cement is applied mainly to production of separate elements – steps, plates. This material is used for production of mixes for filling of floors, abrasive wheels and grinding stones. Aluminous cement on hardening process substantially exceeds other versions. The main component in its structure is clinker. The distinctive feature of such cement – thanks to mixing in certain proportions of cementing agents with special mineral additives, turns out mix which in the course of hardening increases the main volume.
There are several types of the mixed cements which make of the components which are part of similar mixes. The main rule of process of production of such cement is observance of proportions.
The special antifoam component on the basis of carbohydrate is part of any cement. This substance interferes with hit of air in mix, than increases its durability and durability. The stabilizing agent excludes emergence of foam and turns cement into the knitting artificial connection.
Structure and use of cement
Cement is applied in construction not only to production of plates and filling of floors, but also as the reliable connector of other construction materials. Besides lime quite often at cement making use other components of carbonate and clay groups – chalk, marl, slate and lessovidny loams. Obligatory element as a part of any kind of cement are mineral additives. Acidproof material is considered separate type of cement. Its main feature – availability as a part of liquid glass and quartz sand. Such substance has the raised strength indices and is applied generally to construction of rocket mines, bunkers or other objects of defensive or protective assignment.