Investigating the effect of the properties of natural stone materials on asphalt performance using the response surface method

In the road construction industry, natural aggregates have achieved a special position from an economic and technical point of view; in such a way that aggregates form a large amount of materials used in road construction projects. On the other hand, one of the effective factors in asphalt quality is the quality and properties of asphalt stone materials. So, it is very crucial to check the quality of aggregates used in engineering road paving. Therefore, this research was conducted to investigate the effect of natural stone materials on the performance of asphalt pavement, including compressive strength, rutting resistance, and slip resistance using the response surface method. For this purpose, asphalt samples were made with 8 different types of natural stone samples and subjected to Marshall and slip resistance tests and the results of the tests were checked with Design Expert software. The results of this research showed that the Marshall ratio of asphalt samples increases by increasing the resistance parameters of stone materials and the tensile strength has the greatest effect on this variable. In addition, except for the adhesion, the sliding resistance also increases with the increase of the resistance parameters of the stone and the uniaxial resistance of stone materials has the greatest effect on this parameter. Also, according to the relationships presented in this research, it is possible to calculate Marshall's compressive strength, Marshall's ratio, and asphalt slip resistance by having the results of uniaxial resistance, triaxial resistance, shear wave speed, and indirect tensile strength of stone.