Our latest SITREN® Selfheal additives for self-healing concrete combine traditional construction chemistry with cutting-edge biotechnology using special bacteria to seal cracks in concrete prolonging the useful life of buildings.

• Repeated healing of cracks and pores
• Lower water penetration. Improved freeze-thaw resistance
• Densified concrete structure for higher compressive strength
• Reduced CO2 emissions and less concrete waste due to lifetime elongation
• Smooth surface finish and excellent workability properties
• Less out-of order occurrences. Reduced risk of failure. Saving cost and time for repair
• Easy-to-use product
• Formulation based on natural and safe microbes without any hazard labelling

SITREN® Selfheal 455 is a sustainable admixture extending the service life of concrete buildings.


Application Areas

• Groundwater retaining basement walls
• Water reservoirs
• Tunnels
• Bridges
• Pipes
• Dams
• Precast elements - gardening, garages, railway sleepers

The entrainment of uncontrolled air into cement based building materials is unavoidable and leads inevitably to a loss of quality in high performance concrete. Undesired air voids weaken the system resulting in lower mechanical strength and abrasion resistance. In addition, surface air voids often compromise the desired quality requirements of a product.

Defoamers are preferably used for the prevention and removal of large air inclusions at the concrete’s surface and for rapid foam collapse in aqueous formulations. If, on the other hand, it is necessary to remove finely distributed air from a system, deaerators are the preferred alternative. However, practice has shown that a clear differentiation between defoamers and deaerators is usually not possible. Most defoamers also have a deaerating effect to some extent and vice versa.

Application areas

Defoamers are added to plasticizers and hybrid systems (on a chemical basis of lignosulphonates, naphthalenes, melamines or PCE’s) for the production of

• Onsite and ready-mix concrete (incl. lightweight and special concrete)
• Precast concrete elements
• Concrete products (e. g. paving stones and concrete blocks)
• Screed concrete
• Special concrete (e. g. HPC/UHPC)
• Architectural concrete
• Reinforced concrete
• Self-compacting concrete

With the SITREN AirVoid® brand, we offer high-quality defoamers that allow air voids to be selectively removed from the system. This not only results in higher mechanical strengths, an= optimization of the surface and easier workability, but also in meeting the highest demands of aesthetics and durability. Our defoamers can be dosed easily. They can either be added to the plasticizers or directly to the concrete.

Our air entrainers create stable and homogeneously distributed air voids. Their main purpose is to stabilize the air entrained with the water during mixing. Depending on the requirements, our portfolio of airstabilizing additives can optimize the size, content and distribution of the air voids.

Contrary to what the current name indicates, the function of air entrainers is not to generate air voids but to stabilize the mechanically entrained air during mixing. Therefore, air void content is dependent on the mixing process and can vary depending on mixing device, mixing duration, time of mixing, temperature and the additives used.

While the air void content is controlled under more or less defined conditions during the mixing process in a prefab concrete plant, the situation is different if the concrete is transported from the concrete plant to a construction site by truck. The transport of the concrete to the construction site is a factor which is difficult to control, as transport time and ambient temperature can vary. If the concrete is not mixed long enough during the production process or if the air entrainer concentration is too high, the concrete can contain unreacted air-entraining agents. As these are activated by the mixing energy during transportation, the air void content (post-activation) can increase. Conversely, the air void content may decrease due to extended and intensive mixing, or increasing temperatures.

• Onsite and ready-mix concrete (incl. lightweight and special concrete)
• Road paving concrete
• Concrete products (such as paving stones and concrete blocks)
• Screed concrete
• Air-entrained concrete
• Reinforced concrete
• Reinforced concrete
• Self-compacting concrete

Air entrainers from the SITREN AirVoid® range provide increased durability and the option of efficient lightweight construction and improved processing, thus optimizing construction costs and the entire life cycle management of a building. Ideal for the manufacture and processing of air-entrained concrete, in accordance with EN 1992 EC2.

Water repellents are used to provide buildings and roads with durable protection against water and moisture. Our silicone-based water repellents minimize the infiltration of water and dissolved pollutants, while maintaining the water vapor permeability at the same time.

Important requirements for water repellents

• High degree of alkaline stability
• Permeability to gas and water vapor
• Low surface tension
• No sticky surfaces
• Deep penetration depth

Our TEGOSIVIN® brand consists of powerful water repellents, which significantly reduce water absorption and provide outstanding beading properties. This optimizes a building’s external appearance and offers more design freedom; it also guarantees a significant improvement in durability, which in turn leads to lower maintenance costs.

Shrinkage is the term used to describe a reduction in volume of cement-based products due to a change in the water balance. In addition to ambient weather conditions and internal dehydration, chemical/mineral reactions also play an important role. This volume reduction can affect both the shape of the concrete element as well as its bearing points. Restriction of the free shrinkage results in the build-up of internal forces and tensions, which can lead to deformation and crack formation. The most important factors that affect shrinkage include not only low humidity, wind, solar radiation and unfavorable temperatures, but also the individual concrete composition and component dimensions.

Application areas

• In-site and ready-mixed concrete
• Prefabricated concrete
• Concrete products (e. g. paving stones and concrete blocks)
• Concrete screeds
• Special concrete (e. g. HPC and UHPC)
• Architectural concrete
• Reinforced concrete
• Self-compacting concrete

Evonik recognizes that sustainability is of utmost importance for all our futures. As a result, our product development focuses on high-performance products that are friendly to the environment. With this in mind, Evonik has developed a new generation of SITREN® shrinkage reducing agents. Thanks to their extremely low VOC content, SITREN® shrinkage reducing agents are able to meet the most stringent eco label requirements such as EMICODE EC1PLUS – without any dosage restrictions.

The demolding process and the associated use of mold release agents is becoming increasingly important due to the aesthetic demands on concrete structures. Smooth, defect-free and thus visually attractive concrete surfaces are seen today as hallmarks of quality in manufactured building components.
After the concrete has cured the demolding process has to be undertaken with care to avoid damaging the concrete surfaces, especially for visible surfaces, but also in sensitive areas, such as corners, edges and recesses. To ensure a smooth and efficient process, the release procedure between the mold and the concrete must be safe and reliable. Our mold release agents form a protective film at the interface between the mold surface and the fresh concrete to avoid unwanted bonding and build-up.

Our mold release agents are used in almost all molding processes. Depending on the application, very different demands are made on the release agents to be used. Appropriate systems that match the general and working conditions should be selected; this will achieve a dependable and safe mold release procedure.

• Onsite and ready-mix concrete (incl. lightweight and special concrete)
• Precast concrete elements
• Concrete products (e. g. paving stones and concrete blocks)
• Special concrete (e. g. HPC/UHPC)
• Architectural concrete
• Air-entrained concrete
• Reinforced concrete
• Prestressed concrete
• Self-compacting concrete

SITREN® mold release agents guarantee visually excellent concrete surfaces, they also generate enormous cost efficiency thanks to optimized working and usage times. Our products ensure easy demolding process and are readily biodegradable.