Asphalt composites including fly ash fillers or filler blends, methods of making same, and methods for selecting or modifying a fly ash filler for use in asphalt composites

摘要

The present invention is a fly ash filler or filler blend having a particle size distribution with at least three modes that when combined with asphalt produces asphalt composites such as roofing shingles with improved mechanical properties at a lower cost than asphalt shingles produced using conventional calcium carbonate fillers. The present invention also includes a method for producing an asphalt composite, comprising the steps of combining asphalt with a fly ash filler or a filler blend having a particle size distribution with at least three modes and producing an asphalt composite with the resulting filled asphalt. The present invention further includes a method of determining what fly ashes can be used as fillers for asphalt composites such as roofing shingles. The fly ash filler or filler blend can be used in amounts of greater than 45% by volume or greater than 70% by weight to increase the mechanical properties of the asphalt composites such as the pliability, tensile strength and tear strength while decreasing the cost to produce the asphalt composites.