RoadSaver II How It Works

From a platform at the back of the truck-mounted RoadSaver ll® from California Pavement Maintenance Co. Inc., Sacramento, Calif., an operator can monitor aspects of material flow as he or she places an emulsified mix on a road surface. With the press of a button at the operator's control center, the operator can set the computer-controlled, automatic sequencing material introduction system in motion. The manufacturer states that this introduction system allows timing adjustments for delivering aggregate, emulsion, water and additives into the pugmill where they are mixed and distributed to the road surface.
To pour an emulsified mix from the RoadSaver ll, the crew first delivers aggregate to the aggregate bin, which is designed to hold 12 cubic yards (9.2 cu m) of material. Aggregate travels on a hydraulically

driven RSII SuperBelt conveyor to the reversible, twin-shaft, twin-drive pugmill A centrifugal 130 gallons (492 L) per minute pump delivers water from the 750-gallon (2,839-L) water tank and a Blackmer positive displacement vane pump delivers the emulsion from the 600-gallon (2,270-L) tank, both located at the front of the machine, to the pugmill to be mixed with the aggregate.
For mixes that require other additives, a 90-gallon (340-L) liquid additive tank sits toward the back and on the right-hand side of the machine, delivering material via a hydraulically driven pump, which is adjustable at the operator's station. A 16-cubic foot (0.45-cu-m) fines feeder sits above the aggregate bin at the back of the machine, delivering material via a digital ratio meter, and is also adjustable at the operator's station.

Electronic sensors and digital displays monitor the rate at which materials enter the pugmill for mixing, and the speed at which they are mixed. If the sensors detect variation, they are designed to either shut down operation or alert the operator.
Once materials are flowing to the pugmill at a metered and monitored rate, the multipaddle pugmill mixes the materials and augers them out through the hydraulic gate and diverters to a spreader box, or other end attachment, at material output rates ranging from 2 tons to 4 tons mixed (1.8 to 3.6 Mg) per minute, according to the manufacturer. With the automatic sequencing material introduction system, the operator can set or control which material precoats the aggregate, and for how long, before the next material enters the pugmill.