Comparison of the Effect of Novel Additives on the Technical Characteristics of Asphalt Concrete with Topeka grading

Additives have been widely used in asphalt concrete in recent decades, most notably nanocloisite and polypropylene fibers. These additives have been used in civil engineering, especially pavement, to improve the physical and mechanical properties of asphalt mixtures. In this study by adding different percentages of nanocloisite and polypropylene fibers separately and jointly in asphalt mix and performing Marshall tests, data analysis and drawing of necessary graphs, it was observed that these additives increase with Marshall resistance, percentage of space. The asphalt mix vacancy and the percentage of vacant stone materials have a direct and psychological relation, the percentage of bitumen space and the specific weight of the inverse ratio. In the meantime, the composition of nanocloisite and fibers had the greatest effect on the properties of the asphalt mixture, then the nanocloisite individually and finally the fibers had the least effect on the mixture. According to the results and the specification limits, the optimum percentages for the composition of nanocloisite and fibers, 3% nanocloisite and 0.3% fibers were obtained, which had the best effect on the asphalt mixture conditions. The results indicate that nanocloisite has a high filling role, improves the adhesion between the bitumen and the aggregate, resulting in an increase in bitumen volume and eventually increases the bitumen membrane thickness around the aggregates. The fibers are also reinforcing, absorbing materials and bitumen, and react with the chemical mixture.