Plasticizer for screed: its composition, purpose

Plasticizers for floor screed are special substances that are added to the composition of the mortar for flooring, concrete and other mortar, to give ductile properties, as well as significantly improve the existing technical characteristics. Screed plasticizer accelerates and facilitates the mixing of the solution, contributing to the fastest dissolution of liquids, reduction of solid particles, speed and strength of interaction between them.

When pouring a warm floor, it must be borne in mind that the heating agent is unevenly distributed on the floor, only in those places where people walk. When you turn on the heating, the floor in some places is very hot, while in others it remains cold. The temperature changes quickly when the heating is turned on and off.

During operation, the floor:

1. should not crack, crumble;
2. It must be perfectly smooth, not squeezed or rubbed;
3. should warm evenly.

What is a plasticizer for?

A plasticizer for screed underfloor heating, when added to the composition, gives the mixture the following properties:

• up to 30% increases the strength of concrete, as well as its ability to stretch in a frozen state;
• prevents cracking;
• increased resistance to mechanical stress;
• up to 30% the amount of water used for mixing is reduced;
• the amount of cement consumed is saved;
• abrasion resistance increases;
• facilitates the process of filling the floor;
• the composition becomes much more dense, homogeneous, more thoroughly and more closely adheres to the heating elements;
• screed self-leveling;
• thermal conductivity increases;
• water absorption is reduced by minimizing air pores;
• greatly increases resistance to aggressive environments, humidity, fungi, salt deposition, corrosion.

What are the requirements for plasticizers?

These substances should have good compatibility with the selected cement grade, so that during the interaction the mixture acquires the necessary plastic qualities. The additive should have low volatility and no odor. The plasticizing agent must have a high chemical inertness. Also, the plasticizer should not be released from the polymer under the influence of liquids, oils.

Plasticizers for floor heating are used in the manufacture of:

1. floors warm and bulk;
2. couplers;
3. industrial floors;
4. floor slabs.

In addition, these additives are used for interior and exterior surfaces.

The inclusion in the composition of concrete plasticizing additives, allows for construction work both at sufficiently low and high temperatures. The addition of plasticizers allows you to work at temperatures from + 5 C to +35 C.

Screed for underfloor heating It is prepared using liquid, powder additives, emulsions. Plasticizer in the amount necessary for the preparation of a warm floor has been added to the adhesive for the tiles.

The composition of the screed for warm floors includes: one part of cement, three parts of coarse sand (size from 0.5 to 0.8 mm) or fine gravel. Cement and filler are premixed. A plasticizer is added to half the recommended volume of water, gently poured into a mixture of sand and filler, mixed. The rest of the water must be added in portions, until a thick viscous consistency is obtained. The average consumption of liquid plasticizer is from 400 to 800 milligrams per 1 m2 of surface.

The screed for underfloor heating using powder plasticizer has the same composition as with a liquid plasticizing additive, but with the addition of reinforcing fibers made of polyamide.

Today, mixtures for pouring underfloor heating, as a rule, are sold in construction stores in finished form. Buying ready-made building mixtures will allow you to quickly and easily fill the floor, but will significantly increase the cost of work.

If necessary, plasticizers for pouring warm floors may have additional characteristics:

• the presence of an accelerator for hardening cement mixtures;
• an additive that increases the density of concrete during freezing and thawing (can increase the strength of concrete by 20 - 30%);
• additive for surfaces that will be used in conditions with increased corrosion stress, for example, in pools;
• anti-frost hardening accelerator, increases the early grade strength of concrete, accelerates hardening and allows work at temperatures up to minus 15 C;
• anti-shrink effect.

Safety rules when working with plasticizers

These building supplements can cause irritation to the mucous membranes of the eyes and respiratory system. When using them, it is necessary to use personal protective equipment. To protect the lungs, use respirators; to protect the eyes, use safety glasses. Perform work with rubber gloves to avoid skin contact.