Mastic for concrete: features of application, types,

Building a house very rarely does without the construction of the foundation of concrete. But, despite the high quality of the material itself, it also requires some protection from ground and atmospheric moisture. In this article we will discuss two types - waterproofing mastic and sealant for joints (cracks).

Why do you need it

One of the most important enemies of concrete is water, which due to its fluidity can penetrate into the most microscopic pores of the material. After some time, it begins to destroy the base, eventually causing it to become completely unusable.

Bitumen based mastic

This material makes it possible to do waterproofing works with your own hands, even if you do not have sufficient qualifications.

Coverage can:

• be single or multi-layered;
• have a thickness of from 1 mm to several centimeters;
• to form a film that reliably protects the material from water and deformations;
• resist acids and alkalis.

However, only a waterproofing polymer additive will increase the lifespan of this protection to several decades. She will be able to cope well with the expected loads.

Such additives allow hot low-cost bitumen mastic for waterproofing the foundation to acquire greater elasticity and penetration. In this case, you must have a heating tool, and you must comply with fire safety equipment.

Application

In our case, waterproofing mastic will be used for:

• crack repaircaused by sudden changes in temperature.
• creating a hydrophobic film for foundations.
• restoration workswhen separate sections of the concrete base were peeled off and its structure was opened, i.e. large aggregate was exposed.
• waterproofing concrete screeds and seams.

Kinds

Mastic in its characteristics and method of production resembles glue. It differs from it in better viscosity and in the presence of additional components. There are many varieties of it, usually they are divided for use outside the building, which have a well-pronounced weather resistance, or inside.

In composition, they can be:

• bitumen;
• polymeric;
• bitumen-polymer;
• rubber-bituminous.

In addition to the main components, they often include additives, including solvents and fillers. They make it possible to use them as an adhesive, for example, in the manufacture of waterproofing waterproofing concrete foundations. In composition, they are distinguished by:

Advice: if you fail to make a communication channel in the foundation using conventional methods, diamond drilling of holes in concrete will help you.

You should understand that there are mastics intended only for creating waterproofing, and there are those that are used for gluing other materials to the base. Among the large list of the last widespread bitumen, the price is quite acceptable.

There is also a separate version of the mastic, which is called - road. It is intended for waterproofing and sealing the joints and cracks of asphalt and cement pavements.

Due to the possibility of combining different source materials:

• rubber;
• synthetic resins;
• plasticizers;
• fillers,

get materials with high strength and elasticity. In addition, they are resistant to aging and aggressive environments, high and low temperatures.

Subdivide mastic depending on the characteristics of the binder components, they can be:

• elastic;
• plastic;
• not drying out;
• drying out.

The most common are:

• bituminous;
• polymeric;
• polymer-bitumen, combining the properties of the two previous species.

Sealing mastic for concrete joints

In construction use different types of sealants, which differ among themselves:

• the number of components is one- and two-component;
• chemical nature.

The most common:

• acrylic;
• polyurethane - have the best performance for durability, relative elongation, strength and durability;
• from latex.

Technology works

Below is an instruction that describes in detail the process of sealing the joints of a concrete floor with a two-component sealant:

1. Prepare tools and materials:

• hermetic mastic;
• primer for concrete deep penetration - to strengthen the substrate;
• brush - apply a primer;
• narrow triangular spatula - level the sealant layer;
• frame gun - squeeze the sealing compound into the slot.

1. Prepare the basis, which after these works should be:

• strong;
• dry;
• have no signs of fungal infection;
• dust-free;
• free from loose materials, dirt, oil, grease, rust, old paint and other substances, as well as loose particles that can affect the quality of adhesion between materials

For this you can use:

• compressed air blow;
• sandblaster or brush.

Then the plots must be treated with primer.

Tip: after applying the compressor, make sure that there is no oil film left in the seam.

It is recommended to expand the narrow joint before applying the sealant to the concrete; for this, cutting of reinforced concrete with diamond circles is used. It is also necessary to pre-reinforce the base with a concentrated primer.

1. Knead the sealer by mixing the paste with the hardener. Usually it takes 3-5 minutes, the result should be a homogeneous mass. Do not violate the dosage of the components indicated on the package. Otherwise:

• the lack of hardener will not give the sealant enough to harden;
• overabundance - the mass will turn out too hard.

Tip: to increase the fluidity of the material can be diluted with a solvent (white spirit or gasoline) at the rate of 80 g per 1 kg of the composition.

1. Apply sealant with a gun, spreading it evenly over the seam. Take a spatula and level the layer flush with the concrete floor and remove excess material.

Tip: to get a smooth and beautiful seam, moisten the spatula in a soapy solution before smoothing.

The viability of such a sealant is about 40 minutes at + 20? С. When the composition loses it (ceases to be smeared over the surface), apply a layer of sand or cement with a height of 1-2 mm on it. After 5 - 7 days the composition will gain the necessary strength.

Tip: during and after work the room must be thoroughly aired.

The particular elasticity of the material makes it possible to use it for sealing and repairing concrete floors and slabs, for example, holes and cracks in the coating, as well as cracks in the roadway. The composition can withstand temperature fluctuations in the range of - 50? C - + 60? C, which allows its use for outdoor work.

Conclusion

Protection of concrete surfaces - the main properties of the mastic and sealants presented in the article. Their use makes it possible to significantly increase the service life of structures, which saves thousands of rubles. There is nothing difficult in applying mastic and sealants to the surface; you can do this work on your own without much difficulty. The video in this article will help you find additional information on this topic.