Freeze/thaw cycles damage your concrete because there is already a large amount of water within the concrete when winter comes. When the concrete has been saturated with water, either due to a poor mixing process or due to a lack of concrete sealer, the concrete will freeze in the winter. The water inside the concrete causes the material to freeze, which then leads to expansion as the water needs more room to freeze and become rigid. Now, the concretes structural integrity has been compromised, and when that ice begins to melt, the concrete will crack. The cracks are unavoidable once the water within the concrete has frozen.
Concrete is filled with a large number of pores that hold water if the concrete is exposed to a large quantity of water. While moisture passage through the concrete is expected and not harmful, it becomes problematic when the water does not pass through, instead sitting within the material. At this point, it is too late to avoid freeze/thaw damage, as there is really no way to draw water from concrete.
The only way to prevent freeze/thaw damage is to treat your concrete with a quality concrete sealer. Siloxa-Tek 8500 or Siloxa-Tek 8505 are the best sealers to use to prevent freeze-thaw damage and prevent the incursion of water into the concrete. As penetrating sealers, these products will seep deep into the concrete to structurally bond to the material, locking out water permanently. With the water locked out of the concrete, there is nothing to freeze when winter comes, thereby protecting your concrete from cracks when winter is over.