Bricks, Masonry, Asphalt and Concrete - Concrete Step Surface Separating

In July 2005 I replaced my front porch and had some concrete steps installed. The surface was lightly stamped. Last Fall I applied a rather thick coat of Shark Teeth or whatever that sealer is called.

While pushing the snow off of them last week, about one square foot of the stamped surface came, revealing the rock mix below. Evidently water somehow gotten below the surface, froze, and now I have a mess.

The steps never saw any antifreeze material and this is their 3rd winter season.

1. What is the term for this, when the top smooth surface comes off?

2. The top surface is barely a millimeter thick. I expected it to be at least 1/4 inch thick. Is it usual for it to be so thin?

3. Is this a normal occurance? It is starting to happen on other areas of the steps.

4. What steps can I take to prevent this condition from spreading?

that's a ground polycarbonate which's pour'd into sealer then applied to conc,,, failing to keep the mixture stirr'd causes it to fall our of suspension often.

if the steps were properly stamp'd, there shouldn't have been any 'scaling' of the 'cream',,, i'd suspect too much wtr was add'd ('bless'd) when finishing,,, unlikely only 1 area was 'bless'd' as there was only 1 finisher on site.

we'd chip all the surface off & apply a trowel'd topcoat of integral-color polymer-modified cement but that's our work.

you could apply some silicone-siloxane,,, might stop further degradation but won't repair the damag'd areas,,, i don't know of any diy fix's, only the pro methods.