Types of additives in concrete to improve waterproofing

Due to its strength and versatility, concrete is one of the most commonly used building materials in the world. Concrete’s inherent porosity, which can eventually cause water penetration, is one of its drawbacks. This may cause structural deterioration and expensive repairs. Concrete’s waterproofing qualities are improved with different additives to make it more resilient to moisture and more durable.

In order to lessen water’s ability to pass through the pores in the concrete, waterproofing additives fill them. These additives shield the concrete’s internal reinforcement steel from corrosion in addition to keeping water out of the mix. Consequently, buildings have an increased capacity to tolerate severe weather and retain their structural integrity over time.

Additives come in a variety of forms, each with advantages and uses of their own. While some are meant to be applied to the surface once the concrete has hardened, others are meant to be mixed right into the concrete before it is poured. These consist of, among other things, polymer-based additives, water-reducing agents, and crystalline waterproofing agents. Recognizing the various types

Additives to concrete are necessary to improve its waterproofing properties and increase its durability and moisture resistance. Water-reducing agents, which lower the amount of water required in the mix, and hydrophobic agents, which repel water and decrease porosity, are two types of these additives that can be distinguished. Other additives, such as crystalline waterproofing compounds, function by obstructing water pathways in the concrete through the formation of crystals. Builders and homeowners can greatly increase the lifespan of concrete structures by being aware of and making use of these various additive types. By doing so, they can avoid problems like water infiltration and cracking that can require expensive repairs.

What are additives

Air that has entered the mixture is dispersed and all the gaps in the concrete mass are filled with water-repellent additives. As a result, the concrete is compacted and gains moisture resistance, and all of these enhanced qualities endure for the duration of the structure’s service life.

Practical! Molecules that "try to avoid" contact with the aquatic environment are said to be hydrophobic.

Calcium nitrate, silicate glue, and iron chloride are examples of hydrophobic concrete additives.

Moreover, water-repellent additives comprise:

• salts of naphthenic acids;
• paraffin;
• calcium salts;
• stearic acid.

These materials are merely mechanical impurities that serve the sole purpose of increasing waterproofing qualities; they do not interact chemically with concrete mortar.

Any material that can enclose the walls of pores and shield them from the effects of moisture can also be classified as a water repellent.

Additionally, silicone compounds with the following formulas are frequently employed in construction:

• alkoxysilanes;
• hydrogen-containing siloxanes;
• potassium alkyl silicates.

Water-repellent additives also offer additional benefits.

Advantages and disadvantages of water repellents

Certain additives that "lock" pores in concrete have many advantageous qualities.

• Increase the strength characteristics of concrete (due to an increase in the density of the solution).
• Increase the mobility of the sand-cement mixture. Thanks to this, there is no need to use plasticizers.
• They significantly extend the service life of the building, save time and construction resources.
• Increase the water resistance of concrete to level W
• Increase frost resistance by 50-100 cycles.
• Protect the reinforcing frame from corrosion.
• Increase compressive strength by 30%.

Furthermore, new water-repellent additives are now available on the market that not only fill in all the spaces in the concrete "body," but also start to swell when there is more moisture contact with them.

The rise in the concrete structure’s thermal conductivity is the only drawback of adding water-repellent materials. The truth is that the air bubbles in the concrete help to precisely retain heat. The material’s ability to retain heat will be greatly reduced if the hydrophobic additive replaces all of the air. However, with the aid of finishing materials, such issues can be resolved with ease.

The type and brand of waterproofing additives must be considered when selecting them.

Types of additives

The following forms of waterproofing additives are available for purchase: liquids; pre-dissolved compositions in water; and ready-made powders that simply need to be added to the concrete solution.

Concrete waterproofing additives come in three varieties:

• Polymer. If you add this type of additive to a liquid solution, the concrete will become waterproof, its mobility will increase. Polymer compositions cover the fillers (crushed stone and sand) with a protective film, due to which hydrophobization is carried out.
• Plasticizing. In this case, the increase in hydrophobic characteristics is achieved either due to the film that forms inside the composition or due to the fact that the additive particles gain a surface charge. In the latter case, polycarboxylate is used, which is also responsible for increasing the strength characteristics.
• Colmating. These additives increase the grade strength of concrete, making it resistant to aggressive organic and inorganic environments. Penetrating into the cement-sand mixture, the sealing compounds fill its pores with finely dispersed, waterproof, mineral particles and soluble substances. During the hydration process, all components combine and harden.

Practical! A pressure sealant can be used to shield the cracked surface of hardened concrete from moisture.

The mortar’s composition is the determining factor when it comes to the use of additives in concrete for waterproofing. To make a standard cement-sand mixture, you will require approximately one liter of additive for every 100 kg of mixture. When combining lime or gypsum mortars, the additive’s volume drops by thirty percent. Typically, 20 m2 of concrete surface requires no more than 1 liter of water repellent.

Once the waterproofing additives in concrete have been determined, the next step is to identify the best manufacturers.

Improving concrete’s waterproofing qualities is essential to guaranteeing the resilience and longevity of buildings subjected to moisture and inclement weather. In order to increase concrete’s impermeability and resistance to water seepage, additives are essential. Through careful consideration of additive combinations, builders can mitigate the risk of water damage to concrete structures and eventually lower maintenance expenses.

Additives come in a variety of forms, each with special advantages. Water-repellent additives, for example, form a barrier that stops water from absorbing, whereas crystalline additives function by plugging the pores in the concrete, obstructing the water’s ability to enter. Additives based on latex improve the bonding strength and flexibility of concrete, adding another barrier against water infiltration and cracking.

The particular needs of the project and the environmental factors the concrete will encounter must be taken into consideration when selecting the right additive. Knowing the characteristics and advantages of various additives allows builders to make

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