Performance evaluation of stone mastic asphalt mixture with different high viscosity modified asphalt based on laboratory tests

To seek the optimum asphalt binder used in stone mastic asphalt (SMA) mixture of steel deck pavement, the common modified asphalt in the SMA-13 mixture was replaced with high viscosity modified (HVM) asphalt, and the four kinds of HVM asphalts were selected in this paper. The different test methods such as experimental device of mixing power at different velocities, rutting test, Hamburg wheel tracking device(HWTD) test, bending test at low temperature and indirect tensile fatigue test were conducted to evaluate the construction workability, temperature stability, water stability and fatigue performance of HVM asphalt mixture. Besides the performance difference of various HVM asphalt mixture was also discussed. The results show that construction workability of SMA-13 mixture is significantly affected by the asphalt type and mixing temperature, and the influence of mixing temperature on construction workability is more obvious. Besides it is proved that the construction workability of asphalt mixture is influenced by asphalt viscosity and mineral aggregate. The SMA mixture with self-developed HVM asphalt composed by the linear and star styrene-butadienestyrene block copolymer (SBS) modifier has advantages in construction workability and comprehensive properties. Thus the above asphalt can be selected to prepare SMA mixture applied in steel deck pavement. The construction workability, high temperature performance and fatigue performance of HVM asphalt mixture with SBS compound modified asphalt are close to HVM asphalt mixture with TPS additive or HVM asphalt mixture with SINOTPS, and the the former low temperature performance and water stability are superior to HVM asphalt mixture with TPS additive and HVM asphalt mixture with SINOTPS. The dosage of SBS compound modifier in HVM asphalt is just 6.0%, and the blending ratio of linear SBS modifier and star SBS modifier in the compound modifier is 2:1. It means that the self-developed HVM asphalt with SBS compound modifier has the high performance-price ratio. The reduction of key modified materials in HVM asphalt will be conducive to saving the construction cost of pavement, which will promote the HVM asphalt with SBS compound modifier applying in SMA mixture of steel deck pavement. (C) 2019 Elsevier Ltd. All rights reserved.