EVALUATION OF AN INNOVATIVE SEMI-FLEXIBLE PAVEMENT WEARING COURSE MIXTURE USING FAST FALLING WEIGHT DEFLECTOMETER

Road pavements are traditionally classified in three categories, according to their global stiffness. Another type of pavement called semi-flexible pavement has been also successfully applied especially in those areas subjected to heavy and slow moving loads. Semi-flexible pavements are characterized by a wearing course of Grouted Macadam, a composite pavement material. It combines the properties of the asphalt pavements with the concrete ones. On the other side the laying process is slow and expensive, commonly divided into two phases: the laid of the porous asphalt layer and the filling of the voids with a cementitious fluid grout. The realization complexity leads to long realization times and high initial costs. Therefore the use of semi-flexible pavements has been limited to some fields of application and areas. During the last years an innovative material has been developed to be used in semi-flexible pavements. The basic idea was to find an alternative to Grouted Macadam, easier and cheaper to be realized. This material has to provide similar or even superior characteristics compared to traditional Grouted Macadam and meanwhile its construction time has to be reduced, avoiding the need for dividing the laying process. In this paper an experimental program involving the use of FastFWD, as an APT device, to evaluate the long term performances of this innovative material is presented. Results regarding the validation of this new material by means of FastFWD appear promising both in terms of material stiffness evolution and resistance to dynamic load repetitions.