Concrete damage can occur through some of the following means:
Carbonation: Carbon dioxide from the air can react with the calcium hydroxide in concrete to form calcium carbonate in a process which is called carbonation. Carbonation is a slow and continuous process progressing from the outer surface inward, but slows down with increasing diffusion depth. Carbonatation decreases alkalinity, which is essential for corrosion prevention of reinforcing steel.
Chlorides: Chlorides, particularly calcium chloride have been used to shorten the setting time of concrete.However, calcium chloride and sodium chloride have been shown to leach calcium hydroxide and cause chemical changes in Portland cement, leading to loss of strength,as well as attacking the reinforcing steel present in most concrete.
Sulfates: Sulfates in contact with concrete can cause chemical changes to the cement, which can cause significant microstructural effects leading to the weakening of the cement binder.
- Sea Water: Concrete exposed to salt/sea water is susceptible to its corrosive effects. The effects are more pronounced above the tidal zone than where the concrete is permanently submerged. Above the water surface, mechanical damage may occur by erosion by waves themselves or sand and gravel they carry, and by crystallization of salts from water soaking into the concrete pores and then drying up. Sea water corrosion contains elements of both chloride and sulfate corrosion.
In order to prevent the aforementioned concrete damages the use of a concrete sealer will help to prevent and protect substrates and extend the life of concrete. The Siloxa-Tek 8500 is an advanced, high performance, industrial strength water based concrete/masonry water repellent solution designed to reduce water and moisture intrusion. The active ingredients seal the pores within the substrate adequately blocking surface moisture while still maintaining the concretes ability to breathe. It will not significantly modify substrate appearance or traction and will only wear away if the concrete surface itself wears away.