چكيده به لاتين
The mixing design of asphalt mixes requires the manufacture of multiple laboratory samples with different bitumen percentages and calculations in the laboratory. Laboratory results Due to changes in the physical properties of aggregates during the production process to asphalt dispersion, the need for periodic control samples is required. Because of the multiplicity of asphalt samples used in the workshops and the conduct of numerous experiments, it is inevitable to replace common methods. In this study, we tried to find relationships between variables affecting the optimum bitumen percentage, which can be achieved with much less laboratory work. To achieve these relationships, we assumed that the optimum bitumen percentage was a function of the shape, size, and specific surface area of the aggregates and other parameters that were not included in the relationships due to less effect. We established the necessary equations to prove this assumption. For this purpose, by separating the stone materials into three sections, coarse grains, fine grains and fillers, the average size of the stone materials and their specific surface area were determined. As bitumen adsorption of rock materials as well as determination of the percentage of mixing of rock aggregates with different grain sizes are important in the amount of bitumen required for asphalt mixes, the values of each of these parameters have been determined for different mines with different aggregate characteristics in the laboratory. Finally, by determining the numerical values of each of these parameters and constructing statistical models from regression in spss software, we obtained linear equations that determine the optimum bitumen percentage as a function of average rock material size, bitumen adsorption and specific gravity and specific gravity. Specifically the materials that are presented in the last chapter. These equations express the correlation of the optimum bitumen content of the asphalt mixtures based on the properties of the rock material. As with the bitumen percentage of Marshall and Superpave method for Binder and Topka aggregates, results show similar results.
