What have they put?

[Mange RE]

There has been some construction outside the apartment, and I wanted to check, is this cement? I accidentally stepped in the freshly laid area and am wondering what it is. It's been around 50-55 hours since I stepped in it and since then it's developed a dirt-like surface, which is gray but with a much darker color underneath the thin surface. It's hard but you can reach the darker layer underneath. It was wetter at first but has become somewhat semi-hard, and powdery. They laid it on the lawn without any mesh around. Is it clay they have laid then?

 

[Stefan N]

Not cement, looks like joint sand or equivalent.

 

[Mange RE]

Not cement, looks like joint sand or equivalent.

Okay, is it a bit darker and moist/wet at first and then after it has dried a bit, in turn becomes gray?

 

[Strontus]

All finer stone/gravel fractions become darker when wet, only to become lighter when they dry, just like many other materials.