Mechanistic approach for fiber and polymer modified SMA mixtures

In this study, different additives such as mineral fiber, cellulose fiber and styrene–butadiene–styrene (SBS) were used to modify stone matrix asphalt (SMA) mixtures, and performance tests were performed for modified and unmodified mixtures. A mechanistic–empirical design procedure was employed to assess the effect of different additives in improving the service life of the pavement or reduction in thickness of pavement layers. Based on the results, SBS was more effective in improving the performance of asphalt mixtures compared to the fibers. According to the results of mechanistic–empirical design, the service life of the pavement system modified with mineral, cellulose and SBS were 1.07, 1.081 and 1.243 times more than unmodified mix, respectively.

► We examined the laboratory properties and service life of different SMA mixtures.
► SBS could significantly improve the performance and service life of SMA mixtures.
► The difference between two types of fibers was insignificant.
► Just in the draindown test, fibers were more effective than SBS.
► Significant correlations were found between different properties of SMA mixtures.