Full Depth Reclamation (FDR) of paved roadways has historically been undertaken by scarifying the existing asphalt layers with rippers attached to motor graders or crawler tractors. The ripping process produced large blocks of asphalt pavement which were subsequently reduced to smaller, more manageable sizes by travelling hammer mills, grid rollers or similar type equipment. The development of rotary mixers in the 1950’s enhanced sizing of the previously ripped asphalt pavement and increased productivity. Mixing equipment increased steadily in size over the years, but generally the asphalt pavement had to be ripped since rotary mixers could not effectively or efficiently pulverize an un-ripped pavement.
The development and widespread use of cold planing machines and the ease with which they removed and sized asphalt pavements led to the production of large, self-propelled, high horse-powered reclaimers. These reclaimers are equipped with specialty designed cutting drums outfitted with replaceable tungsten carbide tipped cutting tools, which allow the reclaimers to pulverize and mix the asphalt pavement without it first being ripped into large chunks. This development significantly increased production and facilitated sizing and mixing of the existing asphalt pavement and resulted in FDR as it is known today.