Page 59 - RoadCem Manual - PCT BV

It is noted that when RoadCem is used there is no such thing as poor soil for road construction but nevertheless we need to understand the soil classification system before we can do proper pavement design based on RoadCem.
Figure 4.4 gives a comparison of different classification systems in common use today and describes the relationship between particle size classes and different classification systems. Using this figure one can always refer to the Unified Soil Classification System as the base for pavement design purposes.
USCS and other soil classification systems focus on grain size distribution and organic content the primary parameters on which the classification is based. These two parameters also have effect on other soil properties of importance for road construction.
The most important soil properties from the road construction point of view are:
• Grain composition and Colour.
• Soil Structure and Texture.
• Soil Chemistry and Morphology.
• Organic content.
• Consistency (Plasticity, Stiffness, Penetration Resistance).
• Bearing strength.
• Setting behaviour.
• Ground water level.
Each of these parameters is discussed in more detail.
59