Roads & Bridges
Machine attachment facilitates asphalt repair
For contractors involved in full depth reclamation
By Andy Bateman
For contractors involved in full
depth reclamation, there are a number of high capacity machines
available on today’s mobile equipment market. Powered by engines
developing several hundred horsepower, manufacturers offer high
capacity reclaimers and soil stabilisers
|On arrival at a new site, the Asphalt Zipper unit can be connected to a loader bucket in a few minutes utilising a patented hydraulic bucket lock system and quick connect bucket slot.|
For contractors involved in full depth reclamation, there are a number of high capacity machines available on today’s mobile equipment market. Powered by engines developing several hundred horsepower, manufacturers offer high capacity reclaimers and soil stabilisers with cutting widths up to 5 m and cutting depths of over 500 mm. While these machines deliver impressive performance in main line operations, they are simply too big for smaller asphalt reclaiming applications such as street patches, selective road repairs and utility trenches. One manufacturer’s solution is a self-powered attachment that claims both the productivity of larger units and the portability of machine attachments.
Stratford, Ont.-based McCann Paving Inc. specialises in asphalt paving, pulverising and grading, andwas recently called upon to repair a small area of deteriorated asphalt paving behind a muffler shop in Stratford. There, an Asphalt Zipper AZ-360S machine attachment was making a 175 mm deep cut to reclaim old asphalt some 75 mm thick and mix it with 100 mm of underlying granular base. The resulting pulverised mixture was graded and compacted to form the base of 75 mm lift new asphalt without any requirement, for additional imported base material. Carried by a Caterpillar IT28B Integrated Toolcarrier, the AZ-360S pulverised the small 40 m x 15 m (600 m2) repair area in about two and a half hours for an average production rate of 240 m2/hr. McCann’s Jay Armstrong reports that this work is typical of the work done by the AZ-360S, although the unit has also been successfully used to rehabilitate much larger areas such as a three kilometre stretch of rural road for Zorra Township.
Manufacturer’s literature indicates that the AZ-360S weighs 2136 kg equipped with the standard cutter head, allowing it to be towed on its own tandem axle trailer behind a standard 680kg pick up truck. On arrival at a new site, the unit can be connected to a loader bucket in a few minutes utilising a patented hydraulic bucket lock system and quick connect bucket slot.
|The machine mounted Asphalt Zipper AZ-360S has a maximum rated cutting depth of 300 mm.|
The maximum rated cutting depth of the AZ-360S is 300 mm, with the unit’s integral 125 hp John Deere turbo diesel engine delivering power to the cutter head via an oil cooled planetary gearbox. The standard cutter width is 1000 mm, with optional widths of 760 mm and 610 mm available. Replaceable bullet head carbide tipped cutting teeth are said to produce well graded pulverised material that can be reused as road base or backfill. The rated cutting speed of the AZ-360S is 280m2/hr, with the usual caveats on material properties and cutting depth.
According to its manufacturers, the Asphalt Zipper repairs roads and streets faster, cheaper, and with longer lasting results with the power and productivity of much larger machines for a fraction of the cost. The whole operation is said to reduce the cost of the job up to 70 per cent or more and increases crew productivity. In operation, the unit pulverizes asphalt into reusable one inch minus material and leaves a scarified rather than smooth edge. Test have reportedly shown that the interlocking grooves of the scarified edge bind more strongly to the new asphalt to provide a longer-lasting, more waterproof patch that is less prone to slip or settlement. The literature adds that the pulverized base grades very easily enabling the crown to be restored and the curb to be revealed while excess stabilized base can simply be removed and used on other projects.