Concrete rot or concrete cancer is a term commonly used for concrete damage or concrete degradation. Usually this means corroding of the reinforcing steel in the concrete. This is an expansive reaction (rust expands), which makes the concrete crack. This can be very damaging to the strength of the concrete itself and the concrete structure as a whole.
Concrete degradation is caused by carbonation or chloride penetration and usually this happens in difficult circumstances for the concrete: places where road salt is used (bridges for example) and in concrete where hardening accelerators like calciumchloride (CaCl2) have been used to excess. In these cases the protective iron-oxide layer will be broken up.
In carbonated concrete the pH is lowered, causing the protective layer to deteriorate and leave the concrete as FeCl3 and rust to build up.
Another form of concrete degradation is a reaction which occurs over time in concrete between the highly alkaline cement paste and reactive non-crystalline silica, which is found in many common aggregates. This is called the alkali-silica reaction in concrete which causes the concrete to expand and crack.
To combat these problems New Way Technology International BV now has a concrete additive with the properties to influence salts in the concrete in such a way that these will not leave the concrete. By adding the additive during the production process of the concrete, water soluble salts remain fixed in the concrete to harden to a non-soluble state. The steel reinforcement of the concrete will be protected by the additive, remain rust free and concrete cancer will be a thing of the past.
The water vapour can still leave the concrete but the molecular compounds of water, calcium and cement remain in the mortar.
- Improves processability and reduces water use
- Improves water repellency
- Improves resistance against wear and tear
- Improves adhesion and prevents corrosion
- Accelerates drying and hardening processes
- Enhances mechanical resistance
- Frost resistant
- UV resistant