Hi Greg, I used to use a deicer on the sidewalks around my home. I did not have a ramp but I think it would work on the ramp better than salt will. I do not remember the name of the product but if you search for deicers on the Internet I am sure you will find something. It is crystalline and unfortunately more expensive than salt. But the product I used to buy would melt up to 2 inches of snow and crack and dissolve ice at very low temperatures.
I typed in deicers on Google and information comes up from about.com. There are also products listed there. I used to order my deicer by mail and it was delivered to my house. 2 gallons size boxes (I'm guessing) sized lasted me through a southeastern Ohio winter. Just make sure you read the directions carefully and do not leave the deicer close to a heat source because it will melt. Kathy (C6, C7) 44 years post