Page 96 - RoadCem Manual - PCT BV

CBR test
The CBR test is often used to determine the bearing strength. This test is only suitable for testing granular material and not for bound material!
The CBR test shows the bearing strength, for a given moisture content and compaction.
Figure 4.46 CBR devices.
Dynamic slab test
For this test a slab is placed on the ground and a weight is dropped from a height on to the slab. The slab shall be partially pushed into the sub-base. The bearing strength is determined based on the weight, the surface of the slab and the indentation that is made.
Hand/Machine soil drilling
Soil drilling can indicate which kinds of soils are present in the sub-base. A sonar can help show any resistance to the penetration of the cone.
Penetration resistance is the ability of soil in a confined (field) state to resist penetration by a rigid object of specific size. Classes are based on the pressure required to push the flat end of a cylindrical rod (penetrometer can be purchased from many engineering/forestry,/geology/environmental supply centers) with a diameter of 6.4 mm a distance of 6.4 mm into the soil in about one second.
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