1.1. Concrete is classified according to the following basic principles:

According to the purpose of concrete: conventional, hydraulic engineering, concrete for transport construction, road, heat-resistant, structural-heat-insulating, corrosion-resistant.

By density of concrete:
A) especially heavy concrete - a density of more than 2500 kg / m3 (used to protect against radiation exposure).

B) heavy concrete - density of more than 2200 and up to 2500 kg / m3 inclusive (used in all load-bearing structures).

C) lightweight concrete - with a density of more than 1800 and up to 2200 kg / m3 inclusive (it is used mainly in load-bearing structures).

D) lightweight concrete - with a density of more than 500 and up to 1800 kg / m3 inclusive. In enclosing structures (at a density of 500 to 1600 kg / m3), in load-bearing structures (at a density of 1,200 to 1,800 kg / m3).

E) particularly lightweight concrete - with a density of up to 500 kg / m3 inclusive (used as a thermal insulation).
   

By type of binder: cement concrete, gypsum concrete on slag binder, concrete on liquid glass, concrete on slag-alkali binder, polymer concrete, etc.

By the form of additives in concrete distinguish:

A) concrete on dense aggregates (with volumetric water absorption less than 6%).

B) concrete on porous aggregates (with a volume water absorption of grains more than 6%).

C) concrete on special aggregates that meet special requirements (biological protection, radiation, heat resistance, chemical resistance).

                                                                   
Concrete for grain composition: coarse-grained concrete - with coarse and fine aggregate, fine-grained concrete - only with fine aggregate.

Concrete in structure: dense concrete, coarse-porous concrete, porous concrete and cellular concrete

According to the conditions of hardening: concrete of natural hardening; Concrete subjected to heat treatment; Concrete hardening in autoclaves at elevated pressure.

 

1.2. Depending on the ultimate strength of concrete during compression at the 28-day age of natural hardening, concrete is divided into the following classes: B 7.5; AT 10 O'CLOCK; At 12.5; At 15; IN 20; At 22.5; At 25; At 27.5; At 30; At 35; At 40; At 45; At 50; At 55; At 60.
In order for the concrete mixture to easily fit into the formwork, it is good to compact, not to delaminate during transportation, it must have mobility (stiffness) and plasticity.
   

1.3. Concrete mixtures with a high content of water or plasticizer, which have the ability to spread and lay well to fill the mold under the influence of their own weight are called mobile, mixtures with low water content, acquiring fluidity only under mechanical influences (when vibrating) are called rigid.

1.4. According to workability, concrete mixtures are divided into cast, having a cone of OK more than 12 cm, mobile - with OK 2-12 cm, inactive - with OK 0.5-2 cm, hard - with OK equal to 0.

1.5. Concrete is also subdivided into the following types:
                      A) ready-to-use concrete mixes.
                      B) concrete mixes are dry.