I don't have as much experience with the concrete dust, but this is the sort of baseline I would experiment on if I was going for it.
So this was using just castellax bronze to put a thin coat over leadbelcher on treads, and light highlight on edges, a bit of iron warriors for other damage.
If I were to try to get crushed concrete dust I'd probably see what I can do with the lightest dry brushing in targeted areas where dust would build up with seer gray first. Key thing to think about is where the tank would scrape against blocks, and what dust would collect either on contact points, or settle as a cloud and not quickly fall off or wear off
If I'm going to go for rustier settings I start with Mournfang brown on treads, dry with ryza rust, then tone down with typhus often using sponges and retouches, light highlight with iron warriors after, but to me, urbanised might inolve less mud/rust so I'd probably stick with base tread color (e.g. color/metal with castellax/metal dry brush). At a local tank museum many tracks still have good paint matching hull.
Some images to consider