The mechanism
Salt attacks concrete indirectly. It lowers the freezing point of water, so moisture in the surface cycles through freeze and thaw more times per winter than plain water would, and it is hygroscopic, holding that moisture in the slab instead of letting it dry. Every extra cycle expands ice inside the pore structure, and the paste layer loses that fight a little at a time.
What it looks like
Scaling: thin flakes of the smooth surface popping off to expose the sandy layer beneath, concentrated where wheels stop and slush puddles. White residue lines mark where brine pools dry. Left alone the surface roughens season by season, sheds dust constantly, and eventually exposes aggregate.
Repairing a salt-scaled slab
Scaling is surface damage, so the fix is mechanical: grind back to sound concrete, rebuild deeper spalls with resin mortar, then protect the new surface, either a full coating or, at minimum, a penetrating densifier and sealer. Coating over scaling without grinding first just reproduces the rough surface in a new colour.
Prevention is a film, not a habit
A coated floor turns the whole problem into housekeeping: brine sits on the film all winter and mops off in spring, and the slab beneath never sees it. This is the honest reason garage coating in a Canadian climate is slab protection first and appearance second.
Want this answered for your slab?
Free site visit with a moisture reading, then a written fixed price. Across the BC Interior.