Additives to concrete for waterproofing: making an informed choice

Because of its strength and longevity, concrete is a material that can be used in a variety of construction applications. However, keeping concrete structures waterproof is a common problem for both homeowners and builders. Significant harm from water infiltration can include structural weakening, mold growth, and cracks.

There are numerous additives available to improve concrete’s waterproofing qualities in order to address this problem. When combined with concrete, these additives can greatly increase the material’s ability to withstand water intrusion, extending the life of your buildings. But how do you choose wisely when there are so many options available?

It is essential to comprehend the various kinds of waterproofing additives and their advantages. Certain additives function by decreasing the concrete’s permeability, while others produce a surface that is water-repellent. Selecting the best additive will be made easier if you are aware of the particular requirements of your project.

This post will discuss the different concrete waterproofing additives that are available, their benefits, and how to pick the best one for your requirements. By the time it’s over, you’ll know enough to make an informed choice and prolong the life of your concrete constructions.

The need for waterproofing

Why is waterproofing a building’s concrete components necessary? Because of the internal pores and microcracks in the hardened solution, moisture can enter the fill and destroy it from the inside out. Additionally, it’s critical that the concrete not absorb or draw moisture when joining disparate building components with the help of heterogeneous materials, like wood and cement.

By applying additives during the closing solution stage or by using external waterproofing, the concrete structure’s stability against aqueous destruction can be increased. Furthermore, shielding against water will delay internal corrosion and stop putrefactive processes from occurring on the surface.

Types of waterproofing

A series of actions known as waterproofing are intended to reduce the impact of moisture or water on the structure either overall or on specific areas, such as the foundation. There are several methods and materials that can be used to carry out these measures.

The most customary ones are:

• coating waterproofing using bitumen mastic or liquid rubber;
• roll, carried out with materials with a high level of elasticity;
• using clay, including bentonite;
• penetrating and internal using hydrophobic additives.

Unlike an impregnating additive, a waterproofing additive to concrete acts throughout the entire mass of the block, greatly enhancing its quality attributes.

Purpose and principle of operation

The physical characteristics of concrete are altered by a water-repellent additive, which lowers the internal mass of concrete’s coefficient of water absorption. Additives continuously alter the concrete mass’s external porous structure while a building is in use.

The additive material adheres to the inside walls of the capillaries and crystallizes when it comes into contact with any moisture, blocking the flow of water. As a result, gaps or fractures are filled, preventing more damage. Concrete stops allowing moisture to seep through, keeping lime from washing out and preserving the strength of the material.

It should be noted that additives only "repair" the internal walls of the pores, not completely blocking them, which allows the concrete to retain its vapor permeability.

When concrete reaches the strength gain stage, the physical component can choose an appropriate additive that won’t react chemically with the cement to create uniform water drainage, which will lessen the amount of shrinkage.

Naphthalenic acids, calcium salts, and paraffin additives are examples of such additives. They aid in removing air from the solution mass, which lowers porosity, by making the mixture more mobile.

Advantages and some disadvantages

What distinguishes a solution containing additives from a concrete structure that has external waterproofing? There are many clear benefits to concrete that has waterproofing additives added to it. Every external finishing material weakens and cracks with time, lowering the degree of waterproofing.

Furthermore, the process of installing an external protective layer is labor-intensive and time-consuming, and the protective materials themselves are frequently costly. Adding a waterproofing agent to concrete during mixing will initially raise the standard of construction.

This strategy has the following benefits:

• reduction of the estimated volume of work, which entails material savings;
• increase in the service life of the structure;
• simplification of the construction process;
• reduction in the time period for the readiness of a part of the building for further activities;
• significant improvement in the performance characteristics of concrete pouring.

An addition to concrete can raise the mass strength of the concrete by one-third of its original value, raise the level of frost resistance by 100 cycles, and raise the composition’s water resistance coefficient to W20.

Be aware that these additives will shield the internal steel reinforcement from corrosion-related damage and improve its state and longevity.

Although the technology has few drawbacks, the following must be considered when building:

• Waterproofing additives increase the thermal conductivity of the final block, due to the locking of moisture inside the concrete.
• The resulting surface has lower adhesion to plaster and tile adhesive.
• In addition, it is necessary to consider the chemical properties of additives and their compatibility with other additives, if they are used in the work.

Types of additives

The final product’s strength is taken into consideration when selecting an additive for concrete mortar, but other crucial factors should also be taken into account. Water and frost resistance are a couple of them.

Numerous additives available in the construction market can enhance these indicators. Their usage is straightforward: at the construction site, they can be directly poured into the mixer or added while the solution is being mixed.

Be aware that the percentage of cement in the solution drops when you mix in additives. While keeping the grade for strength, concrete’s quality does not decline but rather rises.

What additives are invented for

To ensure comprehensive comprehension, we will categorize additives into the subsequent groups:

• Superplasticizers. Used to reduce the proportion of cement in the solution, thereby reducing the cost of construction. In addition, such additives can change the density, heat resistance and electrical conductivity of the finished block. A significant advantage is the absolute compatibility with other types of additives.
• Frost-resistant. Used for work at sub-zero temperatures. It should be borne in mind that the use of such an additive accelerates the setting time of the solution.
• Biocidal additives in concrete are used to minimize the development of bacteria or various fungi inside the block. Most relevant in the construction of medical institutions, agricultural or livestock complexes, food production.

• Waterproofing. Their use is especially relevant for underground parts of buildings or for structures that are in long-term or constant contact with water.

Let’s examine the ingredients that should be added to concrete to make it waterproof. Additives come in two different forms: powdered dry or solution.

Additionally, they are separated into:

Using additives

For waterproof concrete, additives are added either during the mixing process or when the composition is complete. Their specific gravity typically doesn’t go above 1% of the cement’s mass.

You should carefully read the required conditions before using the additive. Manufacturers provide usage instructions on the packaging.

Speaking of which, 3–4 kg of dry additive per cubic meter should be used if the weight of the cement used to mix the volume of the solution is unknown. M. Concrete.

If a powder additive is selected, it should be diluted with water, strictly observing the proportions. The resulting mixture is introduced into the mixer with the prepared solution immediately after mixing and mixed thoroughly for 10 minutes.

You can learn how to properly mix a solution with a powder additive by watching the video in this article.

Concrete additives provide waterproofing while also enhancing the final artificial stone’s quality and performance attributes.

Water can enter the block through the cracks created when the solution dries and shrinks. Inside, additives create a hydrophobic coating that prevents moisture from entering the pores.

Possible options

When looking through the extensive selection of additives, you should make the right decision by considering the desired outcome.

The following additives are the most widely used:

Any construction project’s longevity and durability depend on the selection of waterproofing concrete additives. You can choose the additive that best meets your needs by being aware of the various kinds that are available, such as crystalline, hydrophobic, and polymer-based additives.

Every kind of additive has benefits and uses unique to it. For instance, crystalline additives block water pathways by reacting with water and concrete to form insoluble crystals. While polymer-based additives improve concrete’s overall waterproofing qualities, hydrophobic additives repel water and stop it from penetrating.

The environment in which the concrete will be used, the amount of water exposure, and the intended waterproofing longevity should all be taken into account when choosing additives. To get the best results, it’s also critical to adhere to the dosage and mixing instructions provided by the manufacturer.

In the end, by lowering the need for repairs and maintenance, spending money on high-quality waterproofing additives can save time and money over time. You can make sure that your concrete structures are sturdy and resistant to water damage for many years to come by making an informed decision.

To guarantee the toughness and longevity of your constructions, selecting the appropriate additives for waterproofing concrete is crucial. This post will walk you through the various kinds of waterproofing additives that are available, their advantages, and how to choose the best one for your particular requirements. You can improve the performance and durability of your concrete projects by making an informed decision by being aware of the benefits and drawbacks of different additives.

Video on the topic

Waterproofing additive to concrete Penetron Admix

Additive to concrete for waterproofing or how to make a screed waterproof.