Design of Pavements Containing Foamed Bitumen Recycled Layers

Cold in place recycling of asphalt pavements with foamed bitumen is a technique traditionally used for base course or subbase construction on low or medium volume roads, but in some recent publications it has been used on heavy trafficked roads to build base courses upon which the bynder course is laid directly. For the last type of applications, improvements of material stiffness are required and they are obtained by increasing the cement content which has the positive effect of reducing permanent deformation, but the negative effect to make the material less flexible. The aim of this paper is to identify a specific design criteria for this type of applications, which is based on the results of experimental tests carried out on these materials, and which try to take into account undesired effects of the high cement content on material performance. A new concept of fatigue life for foamed bitumen stabilized courses could be developed which can be used for the design of heavy trafficked road pavement rehabilitation.