crushed stone voids

[MPENN]

Do you have a line on a chart or graph that will provide a rough estimate of the void ratio for a given stone size. I don't require the accuracy of sampling the stone and calculating the voids. The 2.5" stone is set around precast drywells.

 

[dicksewerrat]

Check with your DOT. They should have that type of info in their spec. book. Drain rock (2.5') is about 90 pounds per cubic foot. That would mean that you haveabout 45%
voids if it is 2.5" only.

 

[Gundam]

I have always used 33% as the void ratio unless I have better information. This may be conservative but usually I am designing a dry well for infiltrating stormwater and clogging can be a factor so a conservative estimate is practical.

 

[SirAl]

It depends upon the specific gravity of the stone as well as the gradation. I use a dry rodded unit weight of 1630 kg/m3 and a specific gravity of 2.68 for the gravels in my location. That would equate to a void ratio of about 0.62 ignoring the pores on the face of the aggregate particles. I suggest that you go to

http://www.unisoftltd.com

and download the UniPhase 2.1 software (free of charge) and play with the numbers.

 

[MPENN]

I am a highway engineer for a State DOT. Our materials lab does not provide this data unless it is specifically requested. And then it is based on a rodded sample from the specific source. I was surprised to find that neither Connecticut nor New York DOTs were able to provide me with void data based on the general gradation and general shape of the material. If the general void ratio of the stone is known and I know the source (specific gravity data on our sources is available) then I have a close approximation to a rodded unit weight.