Conditions for use of fly ashes as filler for hot-mix asphalt

The main purpose of this work is to get to know the structural and functional properties of fly ashes, i.e. industrial waste from lignite-fired power plant, from the perspective of their use as fillers for hot-mix asphalt (HMA). Analysis of the results of laboratory tests: grain-size distribution, specific surface, air voids of dry compacted fillers, stiffening properties in bituminous mastics showed that the fly ashes do not meet the requirements for fillers to HMA, because they cause too much stiffening impact. The results of extensive research has shown that these ashes can be used for the HMA, as so-called the mixed fillers with the participation of limestone filler used traditionally.