Effect of film thickness and voids in mineral aggregate in basic oxygen furnace slag dense-graded asphalt concrete

This research is focused on how the volumetric properties and performance tests for asphalt concrete are influenced by the 100 % replacement of coarse natural aggregates with basic oxygen furnace (BOF) slag. A statistical analysis was conducted to explore whether the replacement of coarse natural aggregate with basic oxygen furnace slag would increase the moisture sensitivity and reduce the strength of asphalt concrete. According to the results of the mixture design, except for the basic oxygen furnace slag asphalt mixture with upper gradation curve, the film thicknesses are from 6 to 9 μm. However, performance tests, especially the moisture sensitivity and creep test, show that the lack of film thickness and void in mineral aggregate did not adversely affect the durability of asphalt concrete. Based on the results of the mixture design and the performance tests, complete replacement of coarse natural aggregates with basic oxygen furnace slag in asphalt concrete is considered feasible and worthy of further study.