Roadtec Shuttle Buggy

Roadtec Shuttle Buggy
Roadtec Shuttle Buggy
Pavng with and without a Shuttle Buggy

The Roadtec “Shuttle Buggy” is a state-of-the-art material transfer vehicle that is used extensively by government roads departments worldwide to achieve consistently high quality asphalt surfaces.

Thermal segregation is one of the reasons that asphalt pavement surfaces fail prematurely. Another reason is aggregate size segregation, which is caused by the same movement of the delivery vehicle as thermal segregation.Even new pavement can show segregation spots - both thermal and aggregate size segregation - caused in great part by the delivery truck.

Offering an unrivalled solution to this problem, the Shuttle Buggy is a mobile silo and on-site mixer for hot mixed asphalt paving material. It is capable of unloading a truck at a rate of 907 tonnes per hour, and re-blending the material to a uniform temperature and stone size gradation. After mixing, the machine sends material to the paver at a rate of 544 tonnes.

The patented triple pitch auger technology is the key to the mixing action of the Roadtec Shuttle Buggy. Steel drag slat conveyor technology aids mixing and carrying of paving material. Rubber belts are a problem because of the heat of the paving material.

The Shuttle Buggy stands between the delivery vehicle and the paver. It receives and remixes the hot material to make the temperature homogeneous.

By eliminating the effect of 'end of load' segregation, the Shuttle Buggy doubles the road life and dramatically reduces maintenance costs. This claim by the supplier has been borne out in studies undertaken by the Washington State Department of Transport (WSDOT) in the USA.

Spot temperatures across the paved (asphalt) mat differing over 14°C are a major problem. These spots will have higher air voids after compaction than the surrounding mix, thus providing a weak spot for the entire structure. These 'over 14°C' projects typically lasted only half as long as ones with uniform temperature. Spots over 7°C will increase the maintenance cost even if they do not halve the service life.

The more uniform the temperature, the lower the maintenance cost over the service life of the road. The temperature of the mat at compaction is not as important as the uniformity of temperature during compaction. By eliminating cold joints and all thermal segregation, ensuring consistent temperature and consistent density, the Shuttle Buggy ensures flawless performance of the asphalt pavement.

The Shuttle Buggy is making its mark. Spain, Ireland, Holland, Sweden, Norway, Australia, New Zealand, China and Russia.

The savings are real and proven. Spain’s Ministry of Transport 'CEDEX' testing agency has data showing that over 5° C differing temperature will have a major negative effect on the service life of the road, and the use of a Shuttle Buggy can double this service life. The paver hopper can hold as much as 12 to 15 tons of mix, making the Shuttle Buggy's 23 tons into a system of 35 to 38 tons and allowing the paver to move without the delivery truck.

The Shuttle Buggy’s conveyor allows two pavers to work with one Shuttle Buggy, which is a feature exclusive to Roadtec, and provides for less trucks to back up traffic and quicker turn-around times for a truck to dump and go.