Exposure Fatigue Life's Prediction Model of Polymer Modified Porous Asphalt with Empirical Phenomenological Approach

Alligator cracking or fatigue cracking is the most important failure of pavements, especially in porous pavements. In this regard, the proposed models that predict the fatigue life of porous pavement can help to enhance the quality of repair and maintenance of roads, especially through the proper schedule. In this research a statistical model based on the results of experimental specimens was generated. Sample beams were made ​​of porous asphalt with about 18% air voids. After specimen preparation, the samples were tested by four-point fatigue test machine and bending stiffness versus the number of loading cycle curve was obtained. Due to the strain controlled test, reaching to 50% of initial stiffness as failure criterion is considered. By paying attention to the experiments and logarithmic regression of results, a model to predict fatigue life of porous asphalt made of SBS polymer modified bitumen based on empirical phenomenological approach was presented. Good correlation coefficient resulted from statistical analysis indicates the proper accuracy of model.