SERPEM is meant for planning of structural strengthening that can predict the remaining life of a pavement with a reasonable degree of accuracy so that the maintenance can be timed to coincide with the onset of critical conditions. The method can design the necessary layer thickness of overlay required to extend the life of a road to carry the predicted future traffic, using standard as well as modified asphalt products as well as reinforced composite structure. This method takes into account the vertical stress, elastic and visco-elastic deflection responses to a load to define the behavioural model. In which fatigue, cracking as well as rutting aspects are considered. It is based on the simple but meaningful relationships defining the load carrying and load spreading capacity, quantified by the equivalent layer thickness and maximum SER (Sustentational Energy Response) coefficient. The SER coefficient is determined from the stress response and maximum elastic pavement deflection. Then it is corrected for the dual wheel load conforming area. The paper shows how the structural deterioration level varies with the variability of the magnitude of structural and fundamental parameters that have been used to define the model. The fundamental values and parameters include the material properties as well as the traffic loading factor N; incorporated into the basic relationships used to define the behavioural model. With the help of several field trials conducted worldwide the paper shows validity of the theoretical concept used in SERPEM to correlate the field performance with the theoretical prediction history. (A)
Abstract