Study on High Temperature Properties of Fiber-Free SMA Mixture

Abstract

: The high temperature performance of asphalt mixture is an important factor to determine pavement life. Through rut test, dynamic modulus test and repeated load creep test, the high-temperature properties of two kinds of SMA asphalt mixtures were compared by different indexes, and the performance characteristics of non-fiber SMA asphalt mixtures were evaluated. The dynamic stability of the mixture and the slope of the creep curve showed that the non-fiber SMA mixture had an advantage in rut development rate compared with ordinary SMA. The estimated road life and flow number Fn based on rutting showed that the non-fiber SMA mixture could bear nearly 80% more standard axle load than the normal SMA flow number Fn by 11%. When the permanent deformation of the mixture reaches the failure stage, the non-fiber SMA can bear more loads. The main curves of dynamic moduli of the two SMA mixtures at different reference temperatures are basically the same, and the dynamic moduli characterizing the mechanical properties of the mixtures have little difference. Compared with ordinary SMA mixture, the asphalt film thickness on the surface of non-fiber SMA mixture is thinner, and the skeleton effect between coarse aggregates is more prominent, which is an important reason for the improvement of high temperature stability of the mixture.