Seal concrete

Technologien und Beratung für den Betonbau - B.T. innovation

Reliable protection for concrete and precast concrete elements

The use of concrete for the production of structural elements, in addition to the question of the optimal formwork, always raises the problem of sealing the concrete parts against pressurized water, rain or general moisture. Whether it is an elaborate project such as a dam wall or an everyday application such as the basement of a home designed as a “white tank”. Making the concrete itself impermeable to water or other liquids is the lesser problem. The real difficulty in sealing concrete is always the construction joints that occur between the individual parts of a structure made of concrete for physical reasons or as a result of the method of manufacture. Reliably sealing construction joints in cast-in-place concrete areas or other construction joints is a considerable challenge in terms of construction technology as well as construction chemistry and requires a lot of know-how.

Sealings for concrete and precast concrete elements must reliably protect against water under pressure and other weather-related influences and also permanently maintain this protection. Foremost, this means that the material must really be suitable for the respective application as a sealing medium. The installed seal made of it must be resistant to aging as well as to the occurring media and their possible admixtures, against which it is to seal. Furthermore, sealing must be so easy to install that the correct installation guaranteeing the function can be carried out even under difficult conditions. However, experience has shown that extremely complex installation does not necessarily equate to the reliability of the sealing technology used.

This results in the core requirements for good concrete sealing technology:

  • High-quality materials suitable for the respective application
  • A system tailored to the specific application
  • Quality guaranteed by the manufacturing process
  • a well thought-out application procedure for uncomplicated processing on the construction site

To meet these requirements, an experienced supplier familiar with the practice on the construction site and with a suitable product range is needed. In addition, competent advice is essential, which ensures that the right product is selected for the individual application.

No two sealing systems for concrete are alike, as there cannot be one process that is ideal for all uses. Essentially, three major areas of application can be distinguished from one another:

  • sealing of construction joints in cast-in-place concrete areas (see joint tape)
  • sealing of precast concrete elements, sealing of concrete surfaces (see sealing slurry)
  • the subsequent sealing of joints in existing structures (building sealing)

Each of these uses is different, with differences in sealing requirements within each area as well. Therefore, B.T. innovation offers you a wide range of products from which you can choose the right solution for your individual task. Learn more about sealing floor slabs here.

In cast-in-place concrete, construction joints are mainly caused by the fact that not all parts of a white tank, a bank wall or a tank can be produced in one operation. In the case of large components, predetermined cracks are also provided, i.e. parting lines that prevent the component from later cracking in an uncontrolled manner due to stress relief. This gives you a predefined predetermined crack joint that can be sealed preventively by a profile. The assembly of precast concrete elements manufactured in the precast plant or directly on the construction site (cavity wall construction method) leads to joints between the precast concrete element joints. In both cases, sealing systems are needed that can be processed together with fresh concrete and bond with it in such a way that no water can later pass between the concrete and the sealant.

An example of a product from this area is the SynkoElast sealing tape. When building a basement, for example, it is inserted into the still fresh concrete in place in the area of the connections of the basement walls after concreting the floor slab. This does not require any additional tools. Even the connection reinforcement that usually protrudes here does not cause any undesirable interference, as the flexible sealing tape can be laid in between without any problems.

With the general need for rationalization and the high cost pressure also especially in construction projects, the use of precast concrete elements has increased strongly in the last decades. A significant problem here is to seal the butt joints between precast concrete elements, especially if, as in the case of basement walls, the concrete structures are built up in the pressurized water zone.

With innovations in sealing technology, such as RubberElast® , this problem can be reliably solved. This is a sealing tape with a high adhesive capacity, which is applied to the joint in each case before the adjacent part is attached. By lining up the next concrete part, pressure is built up due to the compression and the RubberElast reliably bonds with the concrete of both parts, thus ensuring one hundred percent impermeability (see Joining concrete).

RubberElast® bonds reliably not only to concrete, but also to other building materials, such as glass or steel. This allows the architectural possibilities arising from the combination of these building materials with concrete to be exploited without any problems in practical execution.

During renovation and installation work on existing houses, but also during the initial installation of building services in new buildings, the sealing of wall and ceiling penetrations is often required. The aim here is to achieve impermeability between concrete on the one hand and a whole range of materials such as steel, PVC or other materials on the other. For this purpose, the versatile InnoElast adhesive offers the right solution for a really tight seal.

InnoElast is suitable for sealing and filling joints of all kinds due to its excellent chemical properties. It is resistant to environmental influences as well as acids, alkalis and bacterial attack. InnoElast can be applied on damp substrates, even in light frost, and usually without preparing the substrate with a primer. Together with the ProElast waterproofing membrane, InnoElast can also be used for sealing exterior wall joints and cracks against pressing water in strips (see Sealing concrete cracks).

Another product for surface sealing is SurfaceElast, a sealing compound that can be brushed or rolled on and that sets due to the humidity of the air. This sealing measure is especially suitable also for the repair of flat roofs, even if the roof was originally coated with a bituminous mass.

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