Page 69 - RoadCem Manual - PCT BV

Taking ground samples (in-situ)
Samples are taken to measure precisely the composition of the grain. The amount of sample needed depends on the location. When there are different types of soil present then tests must be carried out on all the different soil samples. Different soil types can be visually separated based on their color, change in height, etc. 25 dm3 is needed for each soil sample. This amount is important to carry out extra tests at a later stage. It is also important to weigh the soil sample on the spot before packing it in an airtight bag. In this manner it is possible to determine the moisture content in the sub-base.
Figure 4.18 Measuring the weight of the samples before packing in an airtight bag.
Dry sieve test (laboratory)
The grain composition of the large grains is determined using the dry sieve test. A sample is used for this test which is done in the laboratory. The correct sieve relation is determined between the rocks, gravel, sand, silt or clay. The dry sieving tests can determine which types of soil are present. A wet sieving test is needed to measure the smaller fractions.
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