Building material – cement – people have long been used, since it was necessary to fasten a rapidly hard -hardened substance, which was able to fix, for example, the walls of pyramids or temples.
Cement in Ukraine and Russia began to be released at the end of the 19th century. The properties of this building material are in its composition. Cement is produced by melting lime and clay breeds, resulting in granules called a clinker. It is mixed with a small amount of gypsum, thoroughly chopping.
The resulting product refers to hydraulic substances, the hardening of which is possible in the presence of water. There are several types of cement, each of which differs in its composition. Portland cement leads in terms of issue. The best basis for him is Mergel. This breed is transitional from limestones to clay. Portland cement is white and color, road, hydrophobic, etc.
Cement is indispensable in construction, as it has strength, withstands the pressure of overall structures. Just on this basis, the cement of several brands are distinguished, which indicate the letter M and a certain digit. The figure indicates how many kilograms can withstand 1 kV. cm of finished cement or concrete. For Portland cement, the most common are brands such as M500 cement in bags, M-400, M-550, M-600.This material with an indicator of 600 and above is used for the construction of military facilities.
It is difficult for people to choose cement to choose cement. Therefore, choosing cement, pay attention to the date of its production, take into account that the properties of the material are reduced with monthly. So, over the year of storage, more than half of its qualities will disappear. In addition, it would be nice to feel the cement with your hands: high -quality material will pour out through the fingers like sand, and not get into anyone.
