Clay

Cedar Ridge Materials markets several types of clay and silty sand products. Our primary clay product is a basic Gray Clay composed of fine sands, silt, and clay. In characterizing soil, the “size consist” of the soil particles determines how the soil is classified. Sands are the larger particles and for that reason are generally better drained. Next comes silt while the finest or smallest particles are the clay fraction. The greater the amount of clay the less permeable the soil and the harder it packs. With clay like most products, there is a tradeoff between purity and ease of handling. Without some sand and silts, a pure clay when wet would be very “sticky” and difficult to work. The inclusion of some sand and silt makes the clay soil more workable and improves its flow characteristics. A good way to think of flow characteristics is to contrast the way sugar or salt flows as compared to the way very fine flour or corn starch might flow.

Clay is useful in a number of applications where the user needs a hard packed material with low permeability. Water percolates through clay soils very slowly when compared to a rapid permeability material such as drain gravel. Applications for our clay products include compaction grouting, horse stalls, BMX bike trails, a barrier soil liner for landfills, streams and ponds, or as a soil or soil amendment where a denser clay consistency is required.

Typical sieve or particle size analyses for our Gray Clay and Sandy Silt & Clay products are shown below (product sieve sizes can change so please call for our most recent analysis):

GRAY CLAY SAND CASTLE SAND

Sieve %Passing Sieve %Passing

3/8” 99% 1/2" 100%

#4 91% #4 99%

#8 85% #8 99%

#16 80% #10 99%

#36 69% #16 98%

#60 51% #40 98%

#100 44% #100 68%

#200 34% #200 23%