There are several options available for surface treatments on both horizontal and vertical surfaces of buildings. These surfaces may be constructed from various materials including brick, stone, concrete, tarmac, and slate. Among the major types of surface treatments are penetrating sealers, surface-applied corrosion inhibitors, surface sealers, high coatings, membranes, and overlays. It is crucial that these treatments are applied to a clean, dry, and sound substrate in moderate temperature and humidity conditions within a well-ventilated space.
To apply liquid-applied membranes, a relatively smooth surface is necessary. Before most surface treatments are applied, any necessary concrete repairs must be completed and allowed to cure. The curing time usually lasts 28 days but may vary depending on the repair material. In addition, it is important to review and install expansion and control joints, door and window openings, drains, and curbs correctly to ensure successful application of surface treatments.
Purpose of Surface Treatment
Surface treatment applications are utilized to enhance the appearance and prolong the lifespan of various surfaces. One of the primary objectives of this process is to safeguard surfaces from corrosion. This can be achieved by minimizing the amount of moisture present in concrete and preventing further infiltration of moisture and chlorides.
By reducing the level of moisture within the concrete, surface aesthetics are improved, and damage to the surface is repaired. Furthermore, restricting the ingress of moisture and chlorides can significantly increase the service life of the surface.
Overall, the purpose of surface treatment applications is to ensure that surfaces remain protected and aesthetically pleasing while extending their lifespan. Minimizing corrosion through the reduction of moisture and chlorides is a crucial aspect of this process, which helps to achieve these objectives.
Types of Surface Treatment Systems
1. Penetrating sealers
Penetrating sealers are substances that can be absorbed into repaired concrete. The depth of penetration can differ depending on various factors such as the product, the size of the sealer molecule, and the pore structure in the concrete. While deep penetration is not always essential, it can enhance the abrasion resistance of surfaces. However, it is important to note that penetrants do not have crack-bridging capabilities. Nevertheless, certain hydrophobic sealers may reduce the intrusion of moisture into narrow cracks.
When it comes to the appearance of concrete surfaces, applying these sealers generally does not have a significant impact. In most cases, there may be only a slight change in color. It is worth noting that the sealants do not usually conceal surface flaws.
1.1 Functions of Penetrating Sealer
Penetrating sealers are a popular choice for those seeking effective protection for various surfaces. They offer dual protection by providing water repellent properties and surface hardening capabilities. This means that they not only repel water and prevent it from seeping into the surface, but they also strengthen the surface by increasing its resistance to ultraviolet rays, wear and abrasion.
One of the primary benefits of penetrating sealers is their ability to repel water. By forming a protective barrier on the surface, they prevent water from penetrating the material and causing damage. This is particularly important for porous surfaces such as concrete, brick, and stone, which are prone to water damage. With the use of penetrating sealers, these surfaces are better protected against water damage, and the need for costly repairs is minimized.
Another benefit of penetrating sealers is their surface hardening properties. When applied, these sealers penetrate deep into the surface, creating a chemical bond that strengthens and hardens the material. This results in a surface that is more resistant to ultraviolet rays, wear, and abrasion. In fact, the resistance provided by penetrating sealers is often superior to that of coatings, making them an excellent choice for surfaces that are exposed to harsh environmental conditions.
In conclusion, penetrating sealers are an effective choice for surface protection due to their dual protection capabilities. They provide water repellent properties that prevent water damage, as well as surface hardening capabilities that increase resistance to ultraviolet rays, wear, and abrasion. With their superior performance compared to coatings, penetrating sealers are a smart choice for those seeking long-lasting protection for their surfaces.
1.2 Types of Penetrating Sealers
The following are various types of penetrating sealers available: boiled linseed oil, silanes, siloxanes, certain epoxies, magnesium and zinc fluorosilicates, and high molecular-weight methacrylates. It is worth noting that some of these products are solvent-based, which can contribute to air pollution, while others are water-based. It is important to consider the environmental impact of the sealer before selecting a product for your specific needs.
1.3 Tools for Applications
When it comes to applying a penetrating sealer to a concrete substrate, there are a variety of equipment options available. One commonly used method is to apply the sealer using a roller. This technique involves rolling the sealer onto the concrete surface in a consistent and even manner. Using a roller can be a cost-effective option and is suitable for smaller areas.
Another option for applying a penetrating sealer is to use a squeegee. This technique involves spreading the sealer over the concrete surface using a rubber squeegee in a back-and-forth motion. Squeegee application is often preferred for larger areas as it allows for faster coverage and can produce a smoother finish than a roller.
Spraying the sealer onto the concrete surface is another popular option. This technique involves using a sprayer to distribute the sealer evenly over the surface. Spraying is often preferred for larger areas as it can be more efficient and effective than rolling or squeegeeing. However, it can also be more challenging to achieve an even coverage and prevent overspray.
Regardless of the equipment used, proper surface preparation is crucial for successful application of a penetrating sealer. This may involve cleaning and degreasing the surface, removing any existing coatings or sealers, and ensuring that the surface is completely dry before application. By using the appropriate equipment and ensuring proper surface preparation, a penetrating sealer can be applied to concrete surfaces to protect them from water damage, stains, and other forms of deterioration.
2. Surface-applied Corrosion Inhibitors
Corrosion inhibitors that are applied on the surface are meant to decrease the speed at which corrosion occurs. The degree of efficacy and longevity of these substances is dependent on a variety of factors, such as the characteristics of the concrete, environmental conditions at the site, and the specific type of inhibitor used.
3. Surface Sealers
When working with concrete, sealers and paints are often applied to the surface. These substances adhere to the concrete and create a layer that can be between 0.03 and 0.25 mm thick. Depending on the desired outcome, pigmented or naturally colored paints may be used. Transparent paints, on the other hand, will create a wet or glossy appearance.
It’s important to note that surface sealers don’t have the ability to bridge significant cracks. However, some of these products are hydrophobic, which means they can reduce the amount of moisture that enters narrow cracks. Additionally, certain sealers may fill dormant cracks, although they aren’t effective at bridging small, nonmoving cracks.
Overall, sealers and paints can be useful in protecting and enhancing the appearance of concrete surfaces. However, it’s important to choose the right product for the job and to understand the limitations of surface sealers when it comes to repairing cracks.
3.1 Function of Surface Sealers
The objective is to minimize the impact of water, chlorides, and mild chemicals, as they can cause significant damage to surfaces. Therefore, the aim is to reduce their intrusion and prevent them from penetrating into surfaces as much as possible. This can help to prolong the lifespan of the surface and prevent costly repairs or replacements.
However, in the process of reducing the intrusion of water, chlorides, and mild chemicals, there may also be a decrease in skid resistance. Skid resistance is important as it helps to prevent slips and falls, especially in areas that are prone to wet or slippery conditions. Therefore, it is essential to balance the need to reduce the intrusion of harmful substances with maintaining adequate skid resistance to ensure the safety of people using the surface.
It is also important to consider whether the surface should permit the transmission of water vapor. This depends on the intended use of the surface and the environment it will be in. Allowing the transmission of water vapor can be beneficial in some cases, as it can help to prevent the build-up of moisture and prevent the growth of mold or mildew. However, in other cases, such as in areas where there is a risk of water damage, it may be necessary to prevent the transmission of water vapor to maintain the integrity of the surface.
3.2 Types of Surface Sealers
Certain products used in construction and industrial applications rely on the use of solvents for their effectiveness. However, this can cause issues for the environment and contribute to decreased air quality. These products can also be susceptible to degradation from exposure to UV light and can wear down over time from surface abrasion.
Some examples of such products include epoxies, polyurethanes, high molecular weight methacrylate (HMWM), siloxanes, silanes, and moisture-cured urethanes. In addition, acrylic resins and certain types of paints, such as those containing styrene-butadiene, polyvinyl acetate, acrylic, or blends of these polymers dispersed in water, may also be affected. However, only if the resulting layer is less than 0.25 mm thick.
It is important for those using these products to be aware of their potential impact on the environment and to take precautions to minimize their exposure to harmful chemicals. Proper handling and disposal methods should be followed to prevent negative effects on air and water quality. Additionally, it may be necessary to consider alternative products or methods that are more sustainable and environmentally friendly.
3.3 Tools for Applications
- Brush
- Roller
- Sponge
- Spray
4. High-build Coatings
High-build coatings are coatings that are applied to the surface of concrete and have a dry thickness between 0.25 mm and 0.75 mm. When selecting a protection material for exterior walls and slabs-on-ground, breathability is often an important factor. For exterior environments, the coating must also be resistant to oxidation and UV and infrared radiation exposure.
When it comes to floors, the coating material must be able to resist abrasion and punctures as well as mild chemicals such as salts, grease and oil, and detergents. It is also important that the coating material is durable and that there is a strong bond between the coating and concrete substrate. Overall, the selection of a coating material is crucial in ensuring the longevity and protection of concrete surfaces.
4.1 Functions of High-build Coating
High-build coatings are commonly utilized for both decorative and protective purposes. These coatings can be applied to a surface to enhance its abrasion and skid resistance, and to mitigate the effects of corrosion in repair work. They are also effective in protecting against rain, salts, and mild chemicals.
In addition to their practical benefits, high-build coatings can also change the appearance of a surface, and are sometimes pigmented to achieve a desired color or effect.
However, it is important to note that certain high-build coatings can result in a slippery surface when wet, which may make them unsuitable for use in areas with pedestrian or vehicular traffic. Careful consideration should be given to the specific properties of a high-build coating before selecting it for a particular application.
4.2 Types of High-build Coating
Epoxy resins are a popular choice for repair materials due to their strong bonding and durability properties. They can also be mixed with fine aggregates to enhance skid and abrasion resistance. However, non-elastomeric high-build coatings may not be effective in bridging moving cracks but can be useful for filling small, nonmoving cracks. They offer better wear resistance compared to thinner coating systems.
Various base polymers are used in these products, including acrylics, alkyds, styrene butadiene copolymers, vinyl esters, chlorinated rubbers, urethanes, silicones, polyesters, polyurethanes, polyurea, and epoxies. It’s important to note that some of these products may be solvent-based, which can pose environmental pollution issues.
4.3 Tools for Applications
- Brush
- Roller
- Sponge
- Spray
5. Membranes
Membrane systems are coatings with thicknesses ranging from 0.7 mm to 6 mm that are used to modify the appearance of concrete surfaces. These systems can be applied to the surface of the concrete in three different ways: bonded, partially bonded, or unbonded. For some membrane systems, it is necessary to locate and seal any cracks that are wider than 0.25 to 0.375 mm before applying the membrane.
Preformed sheets can also be used to create a continuous waterproofing membrane, which is achieved by sealing the edges of the sheets. Most of these membranes are designed to be resistant to water absorption and can bridge small cracks that are less than 0.25 mm in size, whether they are moving or nonmoving.
To ensure that the membrane systems meet industry standards, various tests must be conducted. These tests evaluate the membrane’s permeability, elongation, tensile strength, tear strength, adhesion, modulus of elasticity, abrasion resistance, low-temperature flexibility, and water vapor transmission. By performing these tests, manufacturers can provide customers with membranes that meet the required standards and specifications.
5.1 Functions of Membranes
Membranes serve as a versatile solution for a wide range of applications where a protective layer is needed. One common use is in bridges, where they can be used to bridge narrow cracks of various widths, preventing water and other harmful substances from penetrating the structure. This helps to increase the longevity of the bridge and reduce the need for costly repairs.
Another important use of membranes is in waterproofing applications. By creating an impermeable barrier, membranes can be used to prevent water from entering a structure, such as a basement or roof. This can help to prevent water damage, mold growth, and other issues that can arise from excess moisture.
In addition to their waterproofing properties, membranes can also be used as a wearing course for traffic. This is particularly useful for structures such as parking garages, where the surface must be able to withstand the weight of vehicles without becoming damaged.
Finally, membranes can be used as part of damp-proofing systems. By preventing moisture from entering a structure, they can help to prevent issues such as rot, mold growth, and structural damage. This can be particularly important in areas with high levels of moisture, such as basements or crawl spaces. Overall, membranes offer a versatile and effective solution for a wide range of protective and waterproofing applications.
5.2 Composition of Membranes
Elastomeric membranes are commonly found in gray or black color, although some manufacturers offer a range of alternative colors. These materials are composed of various chemical components such as urethanes, acrylics, epoxies, neoprene, cement, polymer concrete, and asphaltic products.
When it comes to durability, elastomeric membranes with a rigid urethane mortar or epoxy-mortar top coat are a reliable option as they provide reasonable skid and abrasion resistance, even under heavy traffic conditions. This added layer of protection can help to extend the life of the membrane and ensure that it remains in good condition for a longer period of time.
5.3 Tools for Applications
- Brush
- Sponge
- Roller
- Trowel
- Spray
6. Overlays
An overlay refers to a deposition that has a thickness of 6 mm or more and can be applied to a concrete surface in various ways. The overlay may be bonded, partially bonded, or unbonded to the concrete surface. The materials and placing methods for the overlays have been previously described. The overlay materials can be made of different types, such as Portland cement concrete, latex modified concrete, polymer concrete, and silica-fume concrete.