Used for the production of cellular concrete (foam concrete, foam gypsum, foam-magnesite). Frothers used to produce a foam that is miscible with the binder (a method of dry mineralization of the foam) or a closed binder. Characterized by a stable foam with a uniform structure. For foaming use a special device – foam generators, porizators, etc. In the XIX century, builders mixed bovine blood, at the beginning of the XX century – soap root. At the present time, in general, ready-made foaming agents are used as marketable products. In such foaming agents, hydrolysates of vegetable and animal proteins obtained on the basis of blood, as well as saponified (kleikanifolny foaming agent, SDO) and various synthetic foaming agents are used as a basis. Frothers, directly introduced into the closed binder. Air in the structure of the material is captured for rapid mixing of the mixture (turbulent method and barotechnology). In such systems only synthetic blowing agent is used, as it quickly foams and withstands high pressure.
When working with foam generators, a protein (also a protein, organic) foaming agent is used, since the already prepared foam solution is combined with the mixture and does not undergo excessive pressure, the foam in this case is more stable and viscous, the interporal septa are thicker, and thanks to this, the end product has higher strength and better performance.
Plasticizers are substances that are introduced into the composition of polymer materials to impart (or enhance) elasticity or ductility during processing and operation. The plasticizers facilitate dispersion of the ingredients, lower the processing temperature of the compositions, improve the frost resistance of polymers, but sometimes impair their heat resistance. Some plasticizers can increase the fire, light and heat resistance of polymers. General requirements for plasticizers: good compatibility with the polymer, low volatility, no odor, chemical inertness, resistance to extraction from the polymer by liquid media, for example, oils, detergents. The most common plasticizers are esters, for example, dioctyl phthalate, dimethyl phthalate, dibutyl phthalate, dibutyl sebacate, dioctyl adipate, dioctyl sebacate, diisobutyl phthalate, tri (2-ethylhexyl) phosphate, phthalic and trimellitic acid esters, orthophosphoric acid esters. Mineral and non-drying vegetable oils, epoxidized soybean oil, chlorinated paraffins, etc. are also used.
Plasticizers are also surface-active additives, which are introduced into mortars and concrete mixtures (0,15 … 0,3% of the mass of the binder) to facilitate laying in the mold and reducing the water content. This improves most of the characteristics of the solidified mixture, and also reduces cement consumption, reduces energy consumption when vibrating concrete (self-compacting mixtures) or leveling screeds (self-leveling self-leveling floor mixes). A widely used plasticizer of this type is the sulphite-alcohol bard. Later, super- and hyperplasticizers with smaller dosages, as well as antifreeze, air-entraining and other useful properties were created.
Due to the chaotic arrangement of cellulose fibers, the fiber has a high bending resistance, it prevents linear mechanical stretching and thermal expansion of the material, performing a reinforcing function . Fiber in the form of fibers or narrow strips is used for disperse reinforcement of concrete structures. This increases the resistance to stretching, abrasion, impact loads. Fiber can be steel, glass, basalt, polymer, polyester.
Fiber improves the characteristics of concrete after a set of concrete strength – performs power functions. First of all, the fiber prevents the formation of shrinkage cracks during the setting of the concrete mixture. Steel fiber, being well mixed, is a uniformly distributed reinforcement in the body of a concrete slab. The application is wide enough; for example, in the production of foam concrete, fire-resistant concrete, prefabricated structures, piles, walls, foundations, bridges and tunnels, decorative products.
Compressor (air compressor)
Compressor (from Latin compressio – compression) is an energy machine or device for increasing the pressure (compression) and movement of gaseous substances.
The capacity of compressors is usually expressed in units of the volume of gas compressed per unit time (m³ / min, m³ / h). Productivity is usually considered according to the indicators given to normal conditions. In this case, the input and output capacities are distinguished, these values are practically equal for a small difference in pressure between the inlet and outlet, but with a large difference, for example, in piston compressors, the output capacity can fall more than twice as fast as the same rotations input capacity measured at zero differential pressure between input and output. Compressors are called incremental if the pressure of the intake gas is significantly higher than the atmospheric pressure.