Impact of Ground Granulated Blast-Furnace Slag as Filler on Performance of Asphalt Mixtures

The objective of this study was to evaluate the impact of Ground Granulated Blast-Furnace Slag (GGBS) as a filler on the properties of HMA and analyze the microstructural dispersion to understand its behaviour. This study considered two mixtures with GGBS at 50% and 100% as a replacement for Stone Dust, and compared the properties of two mixtures with a control mix prepared without any GGBS. At first, two fillers, namely, Stone Dust and GGBS were examined at a microscopic level and it was found that GGBS exhibited more rough and angular surfaces than stone dust. Subsequently, Indirect Tensile Strength (ITS) was carried out to examine the tensile properties at 25 degrees C. The test findings showed that when GGBS content increased in the HMA, the ITS improved both for dry and wet conditions. This increment was measured through a statistical test, and it was found that the increment incurred due to GGBS was statistically significant at 95% confidence interval. It is envisaged that this study had shed some light on the performance of HMA with GGBS through microscopic analysis and, thus advancing state-of-the-art pertinent to the sustainable design practices of pavement construction.