Why are pieces of stones used to cover the ground at electric switchyards instead of just having a concrete floor ?

Question

Why are pieces of stones used to cover the ground at electric switchyards instead of just having a concrete floor ?

In: 4541

Answer 1

It’s cheaper than concrete, requires almost no maintenance, drains well, compacts well for moving heavy gear and trucks, and there is usually a grounding grid built underneath the whole substation which requires the whole area to be dug subgrade and backfilled, for which gravel is a good material.