Hopefully the soil will separate out in layers as shown above. Measure the height of the
different layers and write down your results. From the measurements you can find the
approximate proportions of the different parts of the soil.
HOW TO UNDERSTAND THE RESULTS:
If a soil has 10% (1 tenth - 1/10) clay (the minimum necessary for it to stick together
enough to make blocks) it may only need 5 % OPC to stabilise (1 part cement to 19 parts
soil - 1: 19). For a soil with 30% (almost 1/3) clay, 10% or more cement will be needed
(1:9). More clay than this usually means that it will be too expensive to stabilise the soil with
OPC, lime can then be considered.
EXAMPLE: If the heights are: Gravel 15mm; Sand 25mm; Clay 8mm and silt 2mm. Then the
proportions are as follows:
Total: 15 + 25 + 8 + 2 = 50mm (equivalent to 100%)
Gravel: 15/50 x 100 = 30%
Sand: 25/50 x 100 = 50%
Clay: 8/50 x 100 = 16%
Silt: 2/50 x 100 = 4%
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