Evaluation of Basic Oxygen Furnace (BOF) material into slag-based asphalt concrete to be used in railway substructure

The endurance of a high-speed railway asphalt concrete reinforced trackbed is improved through the use of various percentages of Basic Oxygen Furnace (BOF) slag to replace the coarse natural gravel aggregate of asphalt concrete (replacement rate is 0%, 25%, 50%, 75% and 100%, respectively). We evaluated the performance of BOF-asphalt concrete (which is used as a reinforced trackbed) by performing a modified penetration test, dynamic triaxial test, tensile stress restrained specimen test (TSRST), thermal conductivity test, and dynamic model test. The results show that the penetration time is an alternative index, and all of the BOF-asphalt concretes have a waterproof function. With the increase in the BOF replacement rate, the vibration attenuation, bearing capability, antifreeze capability, and insulation effect are improved, while with the BOF replacement rate increase, the flexural tensile strength loss rate is increased during the long term freeze-thaw cycles.