Concrete Freeze-Thaw Cycles
Freeze-thaw cycles are a common stress factor for concrete structures. Water seeps into surface irregularities (cracks, spalls) and often salt follows in with the water. Water freezes and expands causing damage. Furthermore, salt also re-crystalizes and expands when it is dry, even if it is very cold. In this sense, salt is like a "liquid crowbar" that dissolves and expands as it recrystallizes, magnifying cracks. This salt also attacks rebar, causing it to corrode, which further causes expansive pressure within the concrete, causing and spalling and eventual asset failure.
The Challenge For Existing Preventative Products
Traditionally, asset owners have tried to protect concrete with organic coatings. However, organic coatings have many inherent shortcomings:
Weak Attachment Organic coatings do not bond to concrete. Rather they stick to the surface via a weak mechanical bond. Consequentially they easily separate from the surface that they are intended to protect.
Poor Cold Temperature Performance Cold temperatures place organic coatings "under compression" causing them to delaminate.
Incompatible Flexibility Organic coatings have a different expansion-contraction coefficient than concrete, which also leads to delamination. Even when used to fill cracks, they delaminate inside the crack allowing water and contaminant ingress. Thus, despite the widely marketed flexibility of these coatings, their expansive properties are effectively meaningless on concrete.
Not Breathable Organic coatings do not breath, trapping moisture inside of concrete which expands and contracts throughout freeze-thaw cycles causing structural damage.
Contaminant Trap During their failure and delamination, organic coatings begin to trap contaminants that attack the underlying concrete further accelerating decay.
Weak Shield Organic coatings can be easily punctured or abraded, thus creating an entry point for moisture and biological contaminants.
The bottomline: organic coatings are very poor protective coatings for inorganic structures.
The Zirconia Solution
Zirconia Ceramic Surface Treatments (CST) provide exceptional concrete asset preservation.
Chemically Bonded CSTs chemically bond to the surface and are surface compatible due to similarities in inorganic chemistry and physical behavior. They cannot be separated, once cured to the concrete, because they are now a single composite system (e.g., not two separate layers as with organics).
Flexible Shield CSTs move with the concrete (are flexible), and are not chemically or physically affected by freeze-thaw cycles. CSTs fill in micro- and macro-cracks, and stop the ingress of water and contaminants like salts. Crack filling is stable and permanent. This stops the root cause of freeze-thaw damage. Note, if the concrete cracks due to poor structural engineering or ground movement from underneath, CSTs cannot stop the crack, as they are only 6-10 mils thick.
Breathable CSTs act like Gortex for concrete, meaning the porosity is nano-scaled, stopping liquid water but allowing the surface to breathe.
Inert Material Thus salts and contaminants like oil or other petroleum products from automobiles cannot attack it.
Increased Strength CSTs create a durable near diamond-like hardness (MOHs hardness of > 9) that resists weighted and grating abrasion. Increasing the overall robustness of the surface.
The bottomline: Zirconia Ceramic Surface Treatments are engineered to stop the root cause of concrete freeze-thaw cycle deteroriation.