Page 120 - RoadCem Manual - PCT BV
P. 120

 Figure 5.16 Cross section of a typical road pavement.
A pavement must be designed to meet both functional and structural requirements.
• Functionally, it should serve traffic safety, comfortably and efficiently at a minimum “reasonable” cost.
• Structurally, it is a load bearing structure that is required to perform under prevailing traffic and environmental conditions with minimum maintenance.
The pavement structure transfers the wheel loads from the surface to the underlying subgrade. As shown in Figure 5.19. The wheel load and tire pressure at the surface is effectively reduced within the pavement structure by being spread over a wide area of subgrade. The strength characteristics of the road bed soil dictate the type of pavement structure required to spread the applied load and to reduce the load to a magnitude that can be supported by the subgrade.
Figure 5.17 Spread of wheel load through pavement structure.
In other words, the load bearing capacity of the sub base determines the structure of the pavement, but this is not the only factor. The ability of the pavement structure to spread load over a larger and larger area is just an important parameter that determines the design of the pavement structure. In fact this is where RoadCem approach to pavement design comes in. The RoadCem approach in fact modifies and increases the area of load spreading onto the sub base by the pavement structure and this is because with RoadCemt the material has a higher Elastic modulus and a higher breaking strength.
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