Research: Deflocculation
In a broad sense, deflocculation refers to the process that causes materials to bond together. It specifically refers to the separation of clay particles into their individual components caused either by the material’s chemistry or mechanical action.
The sand in the photo to the left met USGA recommended particle size specifications. The gravel, below, also complied with USGA recommended specifications. None of the materials depicted on this page are suitable for use as root zone or drainage materials. The impact of deflocculation was first documented at ISTRC in 1995. Greens had failed at a course in southern California three months before it was to host a major PGA Tour event. In another instance, all nine greens of a new construction failed. The constant wet/dry pattern associated with establishing seed, created a hard crust like the sand on this page. The young grass could not develop deep root systems. The gravel was rejected before it was installed.
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Bunkers
Root Zone:
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The material in the photo to the right was rejected for the Rose F. Kennedy Greenway in Boston.
Based on the research conducted at ISTRC on the impact of defloc-culation, all materials are evaluated for the condition at NML. It is a property that is common in sands from certain areas of the continental United States. Sands exhibiting deflocculation properties tend to have lower air porosity and lower infiltration rates than sands with similar distributions that do not exhibit the properties.