Materials for European Base and Subbase

Similar to the materials used in the U.S., typical materials allowed for use in the design of European base include asphalt and cement-treated bases, lean concrete base, granular materials (mostly crushed stone), or a combination of these materials. The base is typically constructed on top of a thick subbase layer composed of dense-graded granular materials or lime-stabilized soil. Table 3 summarizes the base/subbase types and their thicknesses frequently used in the Europe.

Many European countries use treated materials such as lean concrete or cement-treated base for the base on top of an aggregate subbase. In addition, to prevent the erosion problem frequently encountered in the base, a recent trend in countries such as France, Belgium, and Netherlands is to place an asphalt interlayer, 2.0 to 3.5 inches thick, between the PCC and the base layer consisting of lean concrete base or cement-treated base [Sommer 2008].