Engineered Fill

Everything is engineered these days, even soil with the discipline of geotechnical engineering. IRL it's called Roller Compacted Concrete, but since we don't have paving machines, a manufactured fill works as a suitable replacement.

Concrete Mixer II
12 Gravel, 10 Crushed Slag, 1 Cement, 2 Water > 24 Fill

Fill has few immediate industrial uses, but when dumped it has the shortest spread distance of any dumped material, almost comparable to a retaining wall and identical to ore (3-tiles @ 5-layers). Making it very efficient for pier wall building, foundations, or for use as a retaining wall. Water is blocked due to the bonding agent (cement), making it a great damming and embankment material.
The only downsides are the micromanagement of dumping the material (thou we already must deal with this) and its few if any other uses.

Image: Oroville Dam Spillway Reconstruction, layers of RCC, 2018, mercurynews.com