Concrete cancer, also known as spalling or concrete corrosion , is a destructive process where the surface of concrete begins to break down and crumble due to water damage, the effects of freezing and thawing, carbonation or corrosion of embedded steel reinforcement. The process of spalling can be accelerated by salt in the air or soil near the concrete, or too high a water – cement ratio in the original concrete mix.
Road and Rail (Bridges, Tunnels, Noise Walls, Safety Barriers)
Signs of concrete cancer include visible cracks, discoloration, flaking or pitting of the surface, downward or outward bulging, and popping or cracking s ounds when stepped on. In some cases, the steel reinforcement from within the concrete may begin to corrode and show through the surface. This can lead to further weakening of the structure, as the steel loses its structural integrity.
Preventing concrete cancer requires proper weatherproofing, proper drainage systems, and the use of quality materials . The most effective way to stop spalling is to apply a water – resistant sealer to the surface. This helps protect the concrete from being exposed to water, which is typically the main cause of the problem. Additionally, it ’ s important to check for signs of corrosion or damage on a regular basis to ensure that any problems are identified and repaired quickly.
Although all concrete deteriorates overtime , when it comes to structural concrete this can have serious and costly impacts if it results in strength or integrity issues.
Unprotected concrete in some tunnel and bridge locations throughout the World have demonstrated as much as 30 mm of concrete carbonation in as little as 20 years into a 100 year design life.In many cases there is only25-35mm of concrete cover over the reinforced steel (rebar) this can represent a huge problem.
Even concrete that is not structural-such as noise walls and safety (jersey) barriers can also benefit from coatings–both aesthetically and from the likes of graffiti
Nanokote’s ProGuard coating technology not only protects concrete assets from concrete cancer it also doubles as an permanent decorative anti graffiti surface. It is also unique in that it can be applied as a single coat directly to damp or dry concrete. The only surface preparation required isa jet wash.