Presenting the Creep Performance Model of Asphalt Using Force-Displacement Curve and Its Validation by Genetic Algorithm

The enormous costs of repairing and maintaining of the existing roads have led to extensive researches in this area. Much of the cost goes to repairing asphalt pavements. On the other hand, the occurrence of permanent deformations in this type of pavement has been recognized as one of the most common causes of the failure of flexible pavements. These deformations are strongly influenced by the creep performance of the asphalt. Understanding and predicting the potential of the occurrence of these deformations in the laboratory phase of specimen fabrication will have a significant impact on reducing pavement repair and maintenance costs. But asphalt creep performance assessment equipment is expensive and out of reach in the current country situation which is under sanctions. In this study, it has been attempted to predict its creep performance by constructing numerous samples of materials commonly used in asphalt pavement construction in Iran and using asphalt stress-strain curve. For this purpose, the force-displacement curve of the Brazilian tensile test was used. This test is done easily and at a low cost with a change in the Marshall Machine jaw. The proposed model shows that by using the parameters of this curve, a proper estimation of creep performance can be obtained. The validity of the mentioned model is confirmed by means of the analysis method of average and also by genetic algorithm.