Laboratory Study of the Effect of Natural Zeolite on the Behavioral Properties of Hot Mix Asphalt

The behavior of the asphalt mixture depends on the characteristics of asphalt binder, aggregate, filler and mixing design. One of the effective parameters in improving the behavior of asphalt mixtures is to modifying the asphalt binder properties using mineral additives. Accordingly, in this research, we tried to study the behavioral properties of asphalt mixtures made with modified asphalt binder with a type of natural zeolite called Clinoptilolite. For this purpose, this material has been used in two percent mass of asphalt binder (2 and 4 percent). In order to investigate and determine the dynamical properties of base asphalt mixtures and modified resilience of the modulus of experiment with indirect tensile strength, fatigue life by indirect tensile fatigue test and rutting potential using repetitive axial loading have been used. The results obtained in this study indicate that the use of this additive has reduced the asphalt binder thermal sensitivity and increased the viscosity and hardness of it, increasing the modulus and the number of loading cycles that led to failure of asphalt samples. Also, the use of zeolite reduces the final deformation in repeated loading experiments and increases the fatigue life of asphalt mixtures. By increasing the amount of Clinoptilolite from 2 to 4% of asphalt binder mass, the modulus of resilience of asphalt samples increases the elastic properties of the specimens and increases the ability to withstand stress. With increasing temperature, the presence of Clinoptilolite in the samples has led to a reduction in the modulus reduction rate and an increase in the depth of their roughness less than the control samples. This, in turn, reduces the thickness of the asphalt process, reduces the probability of occurrence of the slip phenomenon at high temperatures and reduces cracks caused by fatigue at medium and low temperatures.