Crushed stone size limitation for non-expansive frostfree fill

[StructLin]

Hi, Guys, Need help here.

I remember there was a thread before, which discusses about the crushed stone size for use as non-expansive frostfree fill. But I can not find this thread now. Can anybody direct me to that thread or tell me what is the max./min. crushed stone size for non-expansive frostfree fill?

Thank you very much.

 

[CarlB]

If you are referring to non-frost susceptible (NFS) material, the definition is a soil that contains no more than 3% by weight finer than 0.02 mm. A #200 sieve is generally used (0.074 mm), for which the requirement is no more than 5% passing. Whether crushed or not isn't a factor.

No upper size limit, but 3" is a typical upper limit for practical compaction purposes.
For non-expansive, I expect the limit on fines achieves this purpose, but may need to exclude certain sources or mineral types if this is a possibility.

 

[StructLin]

CarlB, Thank you very much.

Yes I vaguely remember in a thread talking about 3" (or 5") maximum crushed stone diameter. So it is probably 3" is what I have seen.

 

[iandig]

There was also some work done by the TRL in the UK where they produced a graph of the grading of materials, and indicated a zone where it suggested' that the soil in this zone' WOULD be suceptible to frost heave. I have attached below the data suggested by the TRL (Soil Mechanics for Road Engineers) dates back to the 1970's but is still a useful good reference.
BS Sieve Size [mm] Upper Limit Lower Limit
150 100 100
125 100 100
90 100 100
75 100 100
37.5 100 100
10 100 100
5 100 100
2.36 100 100
1.00 88 100
0.600 77 100
0.212 58 100
0.100 40 93
0.063 32 85
0.010 14 55
0.002 5 24