[knowbodies]

I wouldn't worry about it at all. It just looks like efflorescence. Waterproofing it likely won't help. Efflorescence is a side effect of water pushing through the concrete from the ground. You can take a look outside and make sure you have adequate drainage around your home - just make sure the ground slopes away and all your downspouts are diverted away. However, you're located in Winnipeg which is a natural floodplain - every spring the ground gets waterlogged pushing moisture up through your garage floor. Structurally, your garage should be fine but you might want to think of parging the concrete if the spalling gets too bad (if it loses 0.5 - 1.0 inches of thickness).