Do you have damaged concrete you wish to repair? Have you tried to repair concrete, but the new cement didn’t stick? Do you need to add fresh concrete to an existing one?
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If you answered yes to these questions, this post is for you. We have researched the proper steps for using concrete bonding adhesives to help you with your repairs.
When using concrete bonding adhesive to repair concrete, follow these steps to ensure that materials will correctly adhere to the concrete:
- Chip and loosen the concrete
- Dust off the surface
- Mix the concrete bonding adhesive
- Apply the concrete bonding adhesive
- Apply the new cement
Throughout this post, we will discuss these steps in detail. We will also talk about other things related to concrete and some tips on concrete bonding. Continue reading to get information on this topic!
How To Use Concrete Bonding Adhesive
Cement or concrete has no binding agent. In this case, wet cement will separate from old cement, even when it dries, if you pour it directly.
A bonding agent aids in the adhesion of concrete and other materials. It can be used to repair chipped concrete or pour new concrete over existing ones.
A bonding agent makes concrete more structurally safe. If you don’t use a concrete bonding agent, the new cement will settle on top and dry on its own; later on, it’ll chip and pull away from the old concrete.
The same principle applies to concrete floors. So bonding agents are also used to repair gaps on floors.
Apart from improving adhesion, bonding agents reduce the porousness of concrete. Therefore, they help reduce cracks. Moreover, they protect concrete from the elements such as frost and UV rays.
The steps illustrated below are for a brush-on concrete bonding agent that is thin, like milk.
1. Chip Or Loosen The Old Concrete
There are situations where you need to chip off the concrete. This is required when you are doing repairs to remove damaged parts. It would help if you used a chisel and hammer for the job.
Make sure you chisel out broken concrete until you reach strong concrete.
Additionally, this step is needed when the concrete bonding agent requires you to do so. Some products can be applied directly, though. It is better to read the label for the product's applications.
If you are doing minor repairs, this step may not be needed. This step is unnecessary if you are putting cement for finishing.
2. Dust Off The Surface
The next step is to clean off the surface. If you did step number one, make sure that you brush off, vacuum, or sweep the dust left from chipping the concrete.
The cleanliness of the existing surface affects adhesion, so it is important to remove debris. Moreover, the bonding agent won't work correctly if you don’t dust off the surface.
3. Mix The Concrete Bonding Adhesive
It is important to note that bonding adhesives have different consistencies depending on the type. Some types need to be diluted in water; some don't need to.
The brush-on type has a soupy consistency.
Before you paint it on the surface, ensure that you have mixed it well. Transfer the liquid into a pail, if you have bought one that comes in a plastic gallon, to be able to mix it properly. You can also shake the container for a few minutes before opening it.
Note that some thin bonding agents can be combined with cement to create a concrete bonding slurry. This mixture results in a paste-like consistency.
This benefits the surface constantly exposed to water since it will increase durability.
Different types of concrete binding adhesive require additional mixing instructions in most cases. Make sure that you check the label for instructions on preparation before starting.
4. Apply The Concrete Bonding Adhesive On The Surface
Apply the bonding adhesive directly to the surface with a brush or a roller.
Refer to the label for the thickness of the application. Make sure that you adhere to the manufacturer's instructions on application timing.
5. Apply The New Cement
Fresh cement can be applied before the bonding agent dries. Use a trowel or spatula to level and smoothen the new cement when the application is made.
Finally, let it dry. You may want to steer activities away from drying cement until it completely cures. Drying time depends on the application's thickness and environmental factors like humidity.
What Are The Different Types Of Concrete Bonding Agents Used In Construction?
A good bonding agent must be easy to use and provide excellent adhesion. It should reduce the permeability of concrete while making it workable.
Three main types of concrete binding agents are epoxy, acrylic latex, and polyvinyl acetate.
Epoxy or Epoxy Resin
This bonding agent is known to have great strength and performance. It doesn’t only bind concrete to concrete but also concrete to steel. It can be used to bind new and old concrete.
Furthermore, it repairs cracks in existing ones.
If you choose this type of concrete bonding agent, make sure that the materials with which this comes in contact will bond. Check the product's label for this information.
Knowing the environmental elements that may affect adhesion, like humidity and cold, is also essential to maximize this concrete bonding agent.
Epoxy-binding agents may be paste-like or water-like liquids.
This bonding agent is primarily used to bond fresh and old concrete. This is a white liquid with 45% solid content, so mixing or shaking the container before use is a must. It has the same consistency as milk.
This type is water-resistant. Apart from concrete, it is also used in other surfaces like stucco, masonry, and cement. Acrylic latex is applied using a brush, spray, or roller.
This is known as PVA. Polyvinyl acetate is a popular bonding agent for cement and numerous substrates. Its primary use is to repair works in concrete.
It protects against moisture, aging, and UV. You can use this type if you are bonding gypsum to interior surfaces.
Does Concrete Stick To All Surfaces?
As mentioned earlier, concrete has no natural binding agent but sticks to wood and plastic.
Because of that, wood panels used as the foundation where concrete is poured have to be treated with a release agent, so cement won't stick to them, as shown in the picture below.
Besides old concrete, fresh concrete does not adhere to many surfaces with molds, paint, oil, glue, and mortar.
If you need to pour cement on molds made of rubber, do not worry, it'll come off when it dries. These are made to resist concrete bonding. Moreover, repairing painted cement won't work unless you remove the paint first.
Paint also has no binding agent; concrete will only separate. In addition, oily surfaces will not make concrete sticks either.
An oily surface needs to be cleaned thoroughly before repair. Brush the surface to remove stubborn oil if you need to repair it.
To Wrap Up
Now that you have read about the steps to use concrete bonding adhesives, you can apply these to complete your DIY project.
When choosing concrete bonding agents, remember that a good one should strengthen the hold of fresh cement to old cement.
Using concrete bonding agents is essential for establishing the strength of newly poured concrete and repaired ones.
You may or may not chip off the old paint before applying bonding agents, but take note that preparing the surface where new concrete will be poured is essential to maximize the product’s adhesion.
The surface needs to be free from debris. Moreover, the preparation or mixing for each product differs per type, so take time to read the product's label for instructions.
Finally, the bonding agent to use depends on how you will use it. This is to ensure you don’t do the same project twice.
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