What are release agents and where are they used?

Combining individual substances with each other is useful in many areas of life. You use it by sticking the hanger on the wall or painting the inside of the cabinet. Adhesion also appears in construction, where it is not necessarily a desirable phenomenon. Read how concrete release agents work and why you should use them.

What is adhesion and cohesion?

In order not to confuse two completely different phenomena, it is worth realizing the difference between adhesion and cohesion . Although both processes involve intermolecular bonds, but:

• In the case of adhesion, they take place outside the substance (e.g. painting walls with paint). Adhesion is the surface joining of bodies and results from intermolecular interactions and the formation of unstable chemical bonds.
• Cohesion takes place inside the body and is based on intermolecular forces of attraction (so-called Van der Waals forces). The value of cohesion is judged by the work required to separate the body into its parts. This is why solids have high cohesion, while liquids and gases have low cohesion.

How do concrete release agents work?

In plastics, foundry and construction, it is often necessary to separate one material from another. This happens e.g. When:

• you take the charge out of the mold;
• you are pouring concrete and you don't want it to stick to the formwork.

This is exactly what anti-adhesive agents are used for, which prevent different surfaces from sticking to each other. If adhesion occurs in the course of the work, there is a very high risk that an attempt to separate the materials will lead to damage to at least one of them.

Thanks to the use of release agents for formwork, you can prepare exactly the form you need and then take it apart without the risk of damaging the concrete surface. Concrete will retain not only its structure, but also a smooth texture, which will be easier to work on later.

The regulations do not introduce specific requirements for anti-adhesion preparations. Only the Polish Standard PN-EN: 13670: 2011 on the execution of concrete structures shows that the anti-adhesive chemistry:

• it must be selected and applied so that it has no detrimental effect on the concrete, reinforcing steel, prestressing steel, formwork and structure;
• shall not unintentionally affect the colour, surface quality of the structure or its individual layers.

Types of release agents for concrete

There are two types of preparations that allow you to separate the surfaces from each other. These are:

• physical (so-called barrier);
• reactive (distinguishing between fully and partially reactive).

Physical agents are in the form of oils or waxes that are applied directly to the element (e.g. formwork). Their advantage is easy application and predictable operation. However, they can leave stains and discoloration on the concrete. For this reason, it is not recommended to use them for facade concrete.

On the other hand, reactive preparations are based on a chemical reaction that takes place between the chemical and the material to which it has been applied (more precisely, calcium ions). These agents are more susceptible to external factors (e.g. temperature or air humidity), but they do not leave a trace on the surface of the material.

To increase the effectiveness of concrete release agents , various types of stabilizers are often added to them, such as EXOemul OM3 LSP . It facilitates the application of the agent by facilitating the dispersion of the oil phase in the water phase, and also improves the mutual compatibility of the ingredients. It is safe for the natural environment.

How to use formwork release agent?

Before applying the release agent, you should clean the surface well. Also, mix the liquid so that it has a uniform consistency without any deposits or lumps. You can apply it manually with a brush.

On large surfaces, however, pressure nozzles will be much better, which will allow you to quickly and efficiently apply an equal amount of the agent. In addition, they save the use of the preparation up to seven times!

Remember not to apply too much chemistry to the formwork, which protects the so-called architectural concrete. It is left in the "raw" phase and is not covered with any plasters and paints, so all discoloration will be very clearly visible.

Try not to apply anti-adhesive agents to the formwork in the immediate vicinity of metal reinforcements. Spraying the bars will make anchoring slower and less effective. This may adversely affect the stability of the entire structure!

How much do release agents cost?

The price of the release agent depends largely on its parameters. Of key importance are:

• application conditions;
• speed of action;
• water resistance;
• agent performance;
• expiration date.

Remember not to be guided only by the price when choosing construction chemicals! High-quality substances produced by reputable manufacturers guarantee effective, efficient and, above all, safe performance of all construction works and an aesthetic effect.

The differences in price can be really big! You will pay for a 5-liter package from a few zlotys (in the case of products available at online auctions, from little-known companies) to even several hundred, if the chemistry has the necessary certificates and is suitable for professional use.

To ensure that you use only the highest quality materials, choose only products from reputable manufacturers. It is a guarantee of comfortable work and safety of building users.

If you are looking for chemicals that will improve the performance of anti-adhesive agents for concrete, check out the Distripark warehouse offer. We guarantee attractive prices, fast shipping and professional advice.

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