"self compacting" backfill

[kozera]

It seems to me that most earthwork contractors consider Size No. 57 stone or something similiar to be "self compacting". Does there exist any aggregate backfill material which is truely "self compacting"? If the answer to this is no, what is the best material and method to place in constricted backfill areas?

 

[Myoho]

A medium to coarse grained angular sand would compact if enough water were poured over it.

 

[cvg]

flowable backfill - sand, aggregate, water and cement - 1/2 to 1 1/2 sack mix, high slump up to 8 inches - this is flowable and self compacting

 

[BigH]

myoho - only if there was sufficient head and the water could escape. I don't know why we continue to give credence to puddling techniques. While I've used them they should be used with caution and not as a matter of course.

 

[boffintech]

Earthwork contractors consider Size No. 57 stone to be "self compacting" because they don't want to pay for labor to compact it. But to do it right and you still need a plate compactor for slab-on-grade applications and to tamp it with the backhoe bucket if used to backfill undercut footings.

 

[LCruiser]

Depends on the material and the application. A fairly well draining material that can use capillary action to suck grains down into place as the submergence sweeps down through the volume works well in deep fills. However, that's not "57 stone".