Abstract: The present invention is directed to means and method for grinding waste asphalt shingles in combination with limestone ore to provide a very fine particulate substance that is suitable as an admix to raw materials used for asphalt shingle production. When grinding the asphalt shingles/limestone ore combination, it was found that the limestone scrubs the asphalt, including temperature softened asphalt, from the grinding mechanism and therefore prevents clogging of the asphalt/limestone ore grinding equipment. According to the teachings of the invention, the limestone and asphalt shingle constituents can be ground into fine homogeneous particulate powder that is free of agglomeration. A desired size reduction was achieved. Ninety-eight percent of the homogenous particulate powder passed through a thirty-five mesh screen.