Conditionally, the composition of cement can be divided into three groups. The first includes high -quality Portland cement, which does not contain mineral additives. This composition is used in the construction of objects, which are endowed with increased requirements for the strength of the structure. The second includes cement, in which organic substances are added. Their content is approximately 20-25%. It is used in the production of parts of the structure, which does not carry heavy loads. And add slag in the third. Such slag cout -cement is used in the production of massive parts of a building from concrete.
The main indicator of the mixture for construction work, which is used for different structures with various requirements that are presented to the structures, is the composition of the cement. In almost all elements of the building, there is cement: when pouring the foundation, when erecting walls, in brickwork, when working with inter -story ceilings, in the elements of the roof. And so, the composition of cement is quite diverse. To date, there are decorative, water -repellent, plasticized, frost -resistant, rapidly hardening and other mixtures.
The cement composition required for construction work is selected in production by mixing different materials. There are various production methods. For example, dry components are used in a dry method. Most often it is clay, as well as limestone. The specified components are crushed into powder. With wet production, water is added. Когда происходит измельчение составляющих, что делает компоненты для дальнейшей обработки более податливыми, вода размягчает их. There are also combined methods of production.
The properties of cement and its composition are determined by how high -quality the components are crushed. In the manufacture, you need to try, how to grind the components as smaller in order to achieve homogeneity. This only favorably affects the further use of building materials. The crushed components provide the required chemical reaction and the speed of hardening. In the manufacture, the constancy of the chemical composition is monitored. After all, his discrepancy with standards and fluctuations at times worsens the quality of products, which will be ultimately.
The cement composition is determined by marking, for example, MPC350 D25, where m indicates the frost resistance of the structure, which will turn out; PC – Portland cement; 350 – the number, which indicates the final characteristics of the strength, so, if all the rules and technologies were observed during construction work, then the structure will withstand weight up to 350 kg/cm2; D – additives of organic origin. Marking D25 means that in the composition of cement 25% of the additives of organic origin. The more organic additives in the composition of cement, the less its strength.