What is concrete sealant, how and where is it used?

Often, during construction or repair work, it is required to reliably seal a section. Today, many different companies produce sealants for concrete and metal. About what it is, where and how it is applied and will be described in the article below.

General information

For concrete surfaces used single-component sealant of high elasticity and high quality. It can penetrate into their depths, ensuring durability and strength of the connection. Put it both on freshly laid, and on old concrete.

When the material hardens evenly, it will begin:

• monitor cracking;
• Prevent the penetration of chemicals and moisture.

Consider some similar products:

1. Specialized sealant for concrete joints - "Accent 117". It is made on the basis of acrylic, is one-component and has a wide scope of use. The material provides a durable and reliable sealing, with a degree of deformability of 15% outside and indoors. In addition, it is used to work with the roof and air ducts. It is recommended to use it during various repair work, in the construction of residential premises, industrial objects, as well as in individual buildings.

Tip: due to the high thixotropy of the material, you can apply it on surfaces with different angles of inclination (horizontal and vertical).

Application:

• Surfaces must first be cleaned.
• "Accent 117" can be used on dry and wet surfaces, but not with the presence of open moisture or drops.
• It should also not carry out work in rain or snow.
• In case of insufficient air humidity, adhesion problems may occur. In this case, wet the surface with a sprayer.

1. Silicone sealant "Accent 128" is made on the basis of polyacrylate, it is also one-component, manufactured according to GOST 30971-2002. It has high adhesion to concrete, foam concrete, metal and brick, natural stone, plaster and wood.

Distinctive feature of the product:

• vapor permeability;
• resistance to UV radiation;
• high thixotropy;
• resistance to precipitation.

Usually, it is used to seal window units from the outside. It helps to remove water vapor, seals the air ducts and roof, provides reliable sealing of joints with a degree of deformability of almost 25%, which is a big indicator. Special mention should be made of the adhesion of this material to tin and galvanized metal.

Tip: if during operation you have to strictly observe the thickness of the layer of sealant, use for this purpose anti-adhesive gaskets made of polyethylene foam.

Two component sealant

In modern construction, sealants have proven their indispensability. They are used in many works, including those related to the sealing of joints and seams, as well as at one of the stages of the screed device.

Sealant is used where it is necessary to ensure the integrity of the structure and prevent the flood and rainwater from entering the structure. To do this, with its help fill the gap between the blind area and the foundation. When constructing concrete floors, they are also used, in particular, a sealant is used for expansion joints in concrete.

They are mastics that can harden under the influence of chemical reagents and air humidity.

For such materials are characterized by the following properties:

• good grip;
• resistance to temperature extremes;
• hydrophobicity.

Therefore, they are used both outside and inside buildings. With proper sealing of joints and seams, a long service life and high mechanical strength of the structure are guaranteed. (See also the article Protecting concrete from moisture: features.)

Sealant for seams in concrete has a reliable grip with the latter, which makes it indispensable when creating a concrete floor.

In addition, it has good adhesion with other building materials, for example, with:

• a stone;
• brick;
• metal;
• lacquered or ordinary tin;
• a tree;
• plastic;
• ceramics.

If you do not violate the instructions and technology, you can ensure a reliable adhesion of the material with the specified surfaces.

Polyurethane Sealant

Due to its resistance to strong vibration, corrosion, humidity and temperature changes, the material is able to ensure tightness between surfaces with particular strength. Some products are even used for joints and seams in flexible joints.

This method was made possible by the high elasticity of the material. Another important parameter is the high rate of solidification. Therefore, it is he who is considered the best facade sealant.

Application

Polyurethane two-component sealants are prepared by mixing paste and hardener. It is very important not to deviate from the technology indicated on the packaging.

Apply the material on a dry, cleaned from dirt and dust surface. The air temperature should not be below -10? C, otherwise the process of hardening can take a long time, for example, at +20? C, it freezes in about 12 hours, and at +5? C - about 18 hours.

Tip: Protect fresh polyurethane sealant from precipitation.

Sealing mastic for sealing seams

From the above information you have learned that in the building industry various types of sealants are used in the work. They differ in the number of major components and chemical nature.

The most common are acrylic and polyurethane. The best performance, including strength, durability, durability and relative elongation of the latter.

Below we consider in detail the process of sealing the expansion joints of a concrete floor with its help.

1. Prepare tools and materials, among them must be:

• hermetic mastic;
• primer brush;
• narrow triangular spatula for leveling material;
• deep penetration primer to strengthen the substrate;
• frame gun for working with sealant, its price is low, but it does a great job.

1. Preparation of the base, which should be:

• strong;
• dried;
• cleared of fungal infections, dust, oil, grease, bulk materials, rust, dirt, old paint.

Remove everything that will interfere with good adhesion of materials. Use to facilitate the work and improve their quality by blowing the area with compressed air, sandblaster or a brush, then treat the place with a primer.

Ensure that no oil film remains in the seam after the compressor. It is also better to slightly narrow the seam and slightly treat the base with a concentrated primer.

1. Prepare a sealant, for which mix the paste and hardener to get a homogeneous mass, usually it takes 3-5 minutes. Do not disturb the dosage of the components, otherwise if the amount of hardener decreases, the material will not be able to harden, and if it is increased, it may turn out to be too hard.

Tip: use to increase the fluidity of the composition of gasoline or white spirit at the rate of 80 grams per 1 kg of composition.

1. Applying sealant is best done with a gun. Evenly distribute the composition over the entire length of the seam, and then level the strip with a spatula level with the concrete surface. Before that, you can dampen the instrument in a soapy solution so that the seam is beautiful and even. Remove excess material. The material can remain “viable” for about 40 minutes at room temperature. After that apply on it a cement layer 1-2 mm thick. Full strength material will reach after 5-7 days.

Tip: while working indoors and after they are finished, it should be well ventilated.

The special elasticity of this material makes it possible to use it not only for sealing concrete floors, in particular, when sealing holes and cracks in them and concrete slabs, but also for repairing cracks in the roadway. The mortar is able to withstand temperature fluctuations in the range of -50? C - +60? C, thereby allowing it to be successfully applied to work on concrete outside. (See also the article Aerated concrete facing: how to do.)

Conclusion

From the article it became clear that there are two main types of sealants for concrete - one-component and two-component. In the latter case, it is necessary to mix the paste and hardener immediately before work.

These materials are indispensable at the construction site, they allow you to reliably seal various parts of structures, protecting them from destruction. The video in this article will help you find additional information on this topic.