In some situations, such as where there is a risk of further alkali aggregate reaction, the concrete structure has to be protected against water penetration.
This can be achieved by the use of different types of products including hydrophobic impregnations, surface coatings and electrochemical treatments.
For many years, Sika has been one of the pioneers in concrete protection through the use of deeply penetrating silane and siloxane hydrophobic impregnations, plus durable acrylic and other resin based protective coatings.
Several of these are also tested and approved for use in conjunction with the latest electrochemical treatment techniques.
All of these Sika systems for the Method “Moisture Control” are fully in accordance with the requirements of EN 1504.
At first sight, concrete seems like a solid material that allows no penetration of aggressive materials. However, the hydration of cement as a binder makes concrete a naturally porous substance. A network of pores and voids of different sizes allows the penetration of different molecules and ions over time.
Depending on their location and use, concrete structures are subjected to a wide range of exposure conditions – from normal atmospheric carbonation to the aggressive influences in polluted urban and industrial environments, plus marine atmosphere and liquid or gaseous chemicals, along with influencers that can damage or attack the concrete and embedded steel reinforcement.
Sika Offers All Types of Technology for Concrete Protection
For over 100 years, we have gained extensive experience and expertise in the repair and protection of concrete. Sika has all the necessary products and systems for technically correct concrete repair and protection.
To adapt the concrete protection method to the specific project needs (e.g. exposure, concrete conditions, time constraints, accessibility, etc.), our customers have the possibility to choose among the following solutions:
Active Corrosion Inhibitors
Using corrosion inhibitors may be a cost-effective solution to deal with corrosion of reinforcement in reinforced concrete structures. It depends on the exposures, environment, quality of concrete and amount of concrete cover.
Based on these factors, passive or active corrosion inhibitors are selected. Neither system alters the concrete appearance.
Passive Corrosion Inhibitors
Passive corrosion inhibitors, which includes hydrophobic impregnations, are a special concrete protection solution applied to reduce water uptake and prevent ingress of water-dissolved contaminants such as chlorides. They are easy and fast to apply without causing any change to the concrete appearance.
Protective Coatings
To provide specific protection such as anti-carbonation or chemical resistance, a film-forming protective coat could be applied on the surface. Such protective coatings are available as rigid, plasto-elastic or elastic systems.
Sika also has anti-graffiti and anti-fly poster coatings to protect concrete, wood, or masonry permanently from deterioration and vandalism.
Cathodic Protection
It is possible to electro-chemically reverse the naturally occurring corrosion current in concrete.
By applying a sacrificial metal (anode) or current, the cathodic protection solution ensures that the steel rebar stays passivated inside the concrete (cathodic mode). It is often the last and most effective way to refurbish critical infrastructure.
