Page 32 - Microsoft Word - 20120528 Unesco study

3.4 Constructions
For this study standard constructions are used. Traditional constructions are based on
standard constructions and roads based on the use of the PowerCem technology are
calculated by PowerCem Technologies. In this paragraph the constructions are described for
the different road and soil types. Also an overview of all the constructions will be given.
The calculations of these constructions are given in appendix 2.

3.4.1 Traditional constructions
The traditional pavement constructions are constructed as shown in figure 3.12.

Base-course

Sub-base
Sub-grade

Figure 3.12: Traditional construction

Sub grade
For the soil types 1&2, an improvement of the subgrade is required, due to the low bearing
capacity of the soil. The improvement of the sub grade will be made with a layer of sand. The
stiffness of the sand layer is dependent on the sub soil.

Sub-base
On top of the sub-grade or the soil, a sub-base will be applied. This sub-base consists of a well
graded and well compacted layer of sand. The thickness of this layer is 0,25m and the stiffness
is E dyn: 150 MPa.

Base course
For all of the construction, a base-course of a granular material will be applied. The thickness
of this layer will be 0,25m and the stiffness of this layer will be E dyn: 600 MPa.

Surface layer
The surface layer consists of asphalt. The thickness of this layer depends on the soil type and
the expected traffic intensity.

The constructions are calculated for the different soil types and traffic intensity. The results are
presented in table 3.8. The pavement calculations of the constructions are given in appendix 2

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