METHOD AND APPARATUS FOR ALTERING AN AGGREGATE GRADATION MIXTURE OF AN ASPHALT CONCRETE MIXTURE

摘要

A method and apparatus for altering an aggregate gradation mixture of anasphaltconcrete mixture. The apparatus includes a heater for heating a layer ofexisting roadwaymaterials, a milling and mixing auger for milling the heated layer of existingroadwaymaterials and a hopper and conveyor for providing a predetermined amount oftreated newusable aggregates to the milling and mixing means for mixing with the heatedlayer ofexisting roadway materials in order to produce a new asphalt concrete mixture.The augerincluding a plurality of milling bits extending therearound for receiving thepredeterminedamount of aggregates and mixing them with the milled layer of existing roadwaymaterials,the milling bits are slanted to direct the aggregates received thereby andmilled layer to acenter line of the apparatus. A second auger is positioned along the centerline of theapparatus and behind the auger for further mixing the new asphalt concretemixture. Ashield plate is adjustably secured to the auger for separating and removingselectedunusable aggregates from the material. The hopper is preloaded with thepredeterminedamount of treated new usable aggregates and the conveyor retrieves theaggregates from thehopper and provides the aggregates to the auger. The new mixture formed by themethodand apparatus has the volumetric requirements for a superpave mix inaccordance with thedesign system developed by the Strategic Highway Research Program of 1987.