Is IT true THAT the use of silicate sealers can lead to long-term concrete damage?
Yes, it is true.
As stated earlier, conventional silicate solutions’ immediate surface reaction can result in an ineffective, incomplete CSH gel. Since the reaction begins immediately upon contact with the concrete’s surface, there is a tendency for more silicate solution to be available in the application than there is hydroxide material in the concrete with which to react. This causes varying portions of the CSH gel deposited inside the concrete to not react completely, thus becoming an incomplete gel – a gel that contains areas that remain susceptible to additional reactions. These unfulfilled reaction areas can eventually react with atmospheric carbon dioxide (CO2) and form carbonates – the source of concrete carbonation that is detrimental to embedded reinforcing steel. The carbonates can also eventually migrate to the surface and cause damage to the concrete that it was meant to protect.
Some conventional silicate reaction by-products can form gel that will absorb moisture and begin swelling, and continue swelling whenever moisture becomes available. This can produce damage inducing internal pressures and stresses – similar to alkali-aggregate reaction.
So, how can DRYCRETE claim the opposite?
DRYCRETE catalyzed colloidal silicate reacts with free alkali to form a 100% solids, water insoluble silica gel deep inside the concrete, without generating heat or expansion pressure. In the initial encounter with free alkali, DRYCRETE hydrates well inside the concrete’s interior, within the transition zone between its surface porosity bottom and its matrix component. This is usually where the internal barrier begins. A minute portion of DRYCRETE in its liquid dispersion, keeps penetrating deeper and deeper, with the unique ability to pass through its own colloidal silicate precipitate.
Unlike concrete surface-activated thixotropic gel-producing silicate solutions, DRYCRETE integrally seals the concrete, in addition to harden and strengthen it.
DRYCRETE has the unique ability to render harmless existent or potentially existent internal steel corrosive activity (if any), by neutralizing internal acids (if any), and removing electrolyte availability.
It also has the ability to arrest or at least significantly retard detrimental internal chemical reactions that may exist, or potentially exist, i.e., alkali-silica reaction (ASR).