6" Minus for backfill in cold weather

[QC73]

We are backfilling a cast in place culvert with 6" minus material. It's mostly rock with some fines. No silt.

Is there an issue with frost? The temprature of material is -10C.

 

[Ron]

Not as much an issue with frost as with lateral ravelling. Lots of voids that can be filled in there...not a great idea.

 

[cvg]

stick with sand and gravels, recommend 3" minus or smaller. 6" is too large. If your subgrade is frozen, expect potential settlement in the spring