Lightweight cellular concrete as retaining wall backfill

[hikeandgolf]

We're doing a design for a retaining wall where the overturning and sliding are perfectly fine, but the soil bearing pressure is way over the geotech's recommended allowable. A suggestion was made to consider lightweight cellular concrete backfill. If lightweight cellular concrete ends up being an option, does anyone have any idea what its cost would be vs. compacted granular backfill? If we specify L.C.C., we'll need to know that its cost is feasible.

 

[MikeHalloran]

My very first real job was working as an office boy for a structural PE, back around 1961.
He had a block of 'MearlCrete' in his office; it fascinated me.
It looked like gray styrofoam, and crushed in your fingers like styrofoam, but smelled like concrete.
The density was a little higher than that of styrofoam, but nowhere near that of concrete.

Much later, I thought it would make excellent insulation, applied in sheets to the exterior of a concrete block house, which is sort of standard in SoFla where termites are plentiful.
... but I couldn't find anyone who was producing it in any form.
Mearl Corp, of somewhere in New Jersey, was trying to license it, but I found no takers.
That was around 1990, I think.

Maybe things have changed and the stuff has found a market.
... but before relying on it for backfill, I'd want to see a successful installation, and I'd be curious about how to protect it from crushing under random foot traffic; it was that frangible.

Or maybe you're looking at something else entirely...





Mike Halloran
Pembroke Pines, FL, USA

 

[WARose]

I remember cellular concrete being just about as expensive as placing regular concrete (depending on the conditions). For a large length of retaining wall, you may want to consider a Solite backfill. Depending on where you are, it can be more economical than many alternatives.

 

[Ron]

I have used lightweight cellular concrete in several applications, even for roof decks, its most common application. I specified it for filling deteriorating hollow fake stones at "a major theme park" in central Florida, to keep the overburden pressure down to prevent settlement. Worked fine, but it cost at least as much as concrete.

Also used it as a higher modulus structural fill under a truck pavement for a paper mill in South Georgia. The road ran across a mucky tidal swamp and needed the strength but light weight of cellular concrete.

Have used it many times for insulated roof decks.

Look up Elastizell or Cellcrete