Ron, thanks for your interest. River Shingle is essentially a pit run material typically recovered from the bed of a river or river channel and is comprised mostly of Cobbles, Gravels and Sand with neglegible content of Silt and Clay particles.
River Shingle is frequently specified for placement below road bases and embankments on weak ground or in wet subgrade conditions. The grading characteristics of river shingle can lead to some difficulty in achieving good compaction in the field or in measuring the actual compaction achieved...
