Abstract: A system for preparing asphalt mix of a selected composition is disclosed wherein the correct proportions of various grades of aggregate to be mixed with liquid asphalt are maintained by repeatedly measuring the weight of aggregate contribution from each of a plurality of feed bins containing different grades of aggregate, comparing the proportion of the total aggregate from all of the feed bins contributed by each individual feed bin to a preselected desired proportion for the particular grade of aggregate contained in that feed bin, and responsive to said comparison, adjusting the rate of feeding of aggregate from that feed bin to correct the actual proportion of the total agregate from that feed bin to the preselected desired proportion. The comparison and adjustment steps are repeated at a selected interval and the proportions of aggregate from each bin are determined based on the average output of each bin over the same interval.