Concrete Sealing Compounds – Features & Types [PDF]

Reading time: 1 minute

Concrete sealing compounds or concrete sealers are liquids applied on the hardened concrete surface to prevent the penetration of deicing solutions, carbon-di-oxide, acids, water, etc. into the concrete. The penetration of such materials results in corrosion of reinforcing steel and cracks.

The important features and types of concrete sealing compounds are enlisted below.

Features of Concrete Sealing Compounds

The main objective of concrete sealers is to protect the surface from corrosion, damage, and stains. Moisture penetration accompanied by freezing and thawing results in cracks in concrete. Concrete sealer hence is the best solution for freezing and thawing problems in concrete surfaces.

Note: The concrete sealing compounds must not be confused with concrete curing compounds. The curing compound serves the function to retard the loss of water from a freshly placed concrete. The curing compound is immediately placed after finishing the concrete surface.

The main features of sealing compounds are:

1. Concrete sealer compounds retard the penetration of harmful substances from the surrounding into the concrete.
2. Concrete sealers are applied only after the concrete structure has gained 28 days of age and strength.
3. The concrete sealers can either block the pores of the concrete or act as an impermeable layer to prevent the penetration of foreign materials.
4. Concrete sealers are essential where the deterioration of concrete due to chemical intrusion, corrosion of steel reinforcement, and alkali-aggregate reaction is a problem. Its application is more in freezing and thaw regions.
5. Chemical concrete sealers can last for ten years or longer. There are varied option of concrete sealers in the market which serves the durability requirements of the concrete surfaces.
6. The sealers extend the useful life of the concrete. Hence, using concrete sealers is an environmentally friendly decision. Among different types of sealers available in the market, water-based sealers are found to be more environmentally friendly.

Types of Concrete Sealers

There are mainly two types of concrete sealers - Topical Sealers and Penetrating sealers.

Topical Sealers

The topical concrete sealers provide topical protection to the concrete from stains and external chemical action. These types of sealers also provide visual enhancement to the surface. The topical sealers are applied on a dry and clean surface.

One important issue with these sealers is that they make the surface skid, when wet. It is because the sealer reduces the traction coefficient and imparts gloss to the surface. Anti-skid materials can be used as a remedy for this problem.

Topical sealers can last from one to 5 years. High-end epoxy or urethane system topical sealer polymers can last for a more extended period. Example: Acrylic Sealers, Epoxy Concrete Coatings

Penetrating Sealers

The penetrating sealers penetrate the concrete surface to serve the purpose of sealing. It reacts within the concrete creating a chemical stable compound that acts as a breathable barrier just below the concrete surface. The sealers provide a natural look to the surface. Penetrating sealers do not modify the substrate appearance or traction.

The application of penetration sealers are made on dry or damp surface. The sealer must adequately match with the porosity of the substrate to have effective penetration into the surface and reaction. The lifespan of penetrating sealers are more significant than five years. Example: Silicates, siliconates, silanes, and siloxane.

Frequently Asked Questions on Concrete Sealers

Read More:

• Maintenance of Concrete Structures for Durability of RCC Members
• Surface Treatments for Walls, Roofs, and Floors: Types and Purposes