The map icon for these challenges looks just like the achievement tile. You must beat the pro time of each Demolition challenge to get this. The challenge involve different ways of taking down structures. Usually, the best way is to go for the lower supports and let the building topple over itself.
These are found in each sector of mars. There are 16 total. Check how far along you are in the statistics achievement progress menu. Also, check out this thread for hints and tips on beating pro times.