MnDOT specifications for granular filter material under Class I random riprap
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Granular Filter Material Under Class I Random Riprap
Sieve Size Percent Passing by Weight
2 inch -
1.5 inch 100
1 inch -
3/4 inch 70-100
3/8 inch 45-90
No. 4 35-80
No. 10 20-65
No. 40 10-35
No. 200 3-10