Other blocks
Bridge Concrete Block
A composite material composed of sand, stone, and cement. Can be upgraded to Steel.
Upgrade path
Hit a placed block with a stone axe, claw hammer or nail gun while carrying the material of the next step: 4 hits per upgrade.
Harvest drops
Small Stone× 25
Taken apart with a harvesting tool (axe, pickaxe, shovel), before perks and tool bonuses.
When it collapses
Falling, it leaves 
Destroyed Stone (75% of the time) where it lands.
Where to find (1 POIs)
Water Works (tier 4).
Points of interest built with this block (any of its variants), the highest tiers first, from the game's prefab files.