Background..my yard is land reclaimed from a salt marsh. Once I dig down 12-18" I run into a 1' thick layer of very coarse aggregate consisting of potato rocks, and pieces of roadbed, concrete, bricks, clay drain tile shards, large gravel, medium gravel and small gravel, etc.. Below this layer is 1-2' of pure amber-colored sand.

When I dig out an area for a new bed, I screen the soil and sand to remove everything larger than 1/4" and I am accumulating a mammoth pile of this stuff. I'm starting to sort it out based on attractiveness, etc..

Is there a way to use this coarse aggregate in hypertufa, or some sort of concrete mix, for troughs, raised bed sides, bed edging, etc.?

As an example, I'd like to make large blocks, and place the potato rocks and more attractive large gravel in the bottom of the mold, to act as the surface of one side of the block. These would then be used to build short walls, with the 'pebbled' surface facing out.

I'm not sure I'm explaining this clearly, but the primary goal is to put the ugly coarse aggregate to use as bulk in these projects, and use the better looking stuff as visible surfaces.