The Functional Design of Porous Friction Courses (PFC)

The paper deals with the issue of the rainwater drainage from porous friction courses. It presents an original method for the functional design of porous friction courses. Given the geometric characteristics of the road and the rainfall intensity, the method can be used to assess both the correct permeability and thickness of the porous layer to avoid the presence of water films over the pavement. If under the porous friction course sub-drains are placed, the method can be used also to assess their spacing. First of all, the paper presents and discusses the mathematical models which the design method is based on, and their experimental validation. Afterwards the method is presented; it is based on the use of some original charts drawn to give a prompt solution to the design problem. The paper ends with a practical application of the proposed methodology