Effect of Warm Additive on the Performance of Flexible Pavement on different Subgrade based on Numerical Analysis

The application of additives is the factor affecting the properties of asphalt mixture. These additives can also change the performance and response of the pavement versus loading. Sassobite is used as an additive to produce warm asphalt. So far, there has not been done a complete study on the impact of these materials on the performance of the pavement, on the software scale. In this research, it has been tried to develop a three-dimensional model of pavement based on experimental results and by using finite element software, with its surface layer being from semi-warm asphalt and to identify critical reactions of the pavement under the surface layer and on the subgrade soil. The research process is such that changes were made in different modeled pavement variables, and a comparison was made between the variation of the reactions in the control pavement and the pavement having the additive. In addition, the effect of changes in the thickness of the pavement and the modulus of the subgrade has been the subject of this study. The aim of this study was to compare the performance of the two types of asphalt mixtures on conventional and stabilized subgrade. The results of the analysis show that the use of additives, in addition to increasing the modulus of elasticity of the asphalt pavement, significantly reduces the tensile strain of the asphalt substrate in the control pavement. In addition, the compressive strain on the subgrade also decreases. The results showed that increasing the thickness of the asphalt pavement layer in comparison with the use of the additive has a greater effect on the reduction of critical strains.