Page 84 - RoadCem Manual - PCT BV

4.2.5 Soil Structure
Soil structure is another aspect of soil description that must be considered in order to evaluate a soil. Soil structure relates to the bigger picture of how water will move in the soil. Soils with a good texture may be foiled by a poor structure. One definition of soil structure is the grouping of individual soil particle into a larger grouping. You can also thinks of structure as a brick house in that the brick, mortar and cement are the particles (i.e. texture) and the completed house is the structure. We are concerned about structure because of its relation to use of soils as a road building materials or sub bases.
Certain structures are more likely to be restrictive to water movement and thus more suitable for road construction for example.
Structure is the naturally occurring arrangement of soil particles into aggregates (peds) that result from pedogenic processes. There are three general groups:
1. Natural Soil Structural Units (pedogenic structure).
2. Structure less.
3. Artificial Earthy Fragments or Clods.
These soil structure is described by using 3 components: type, size, and grade, Figures 4.35, 4.36 and 4.37.
Figure 4.35 Pedogenic soil structure.
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