From May to August of this year, The City’s 14 asphalt hot boxes filled over 5,000 potholes. The hot boxes are a single-purpose piece of equipment, and can’t be used without an operator.
“Our crews started looking for a multi-functional piece of equipment,” says Roads Maintenance Manager Bill Biensch. “There were products on the market but they did not fulfill all our requirements.”
So instead, a City-specific design was created. With a focus on increasing utilization of City fleet, Fleet Services, in collaboration with Roads, designed a new slide hot asphalt carrier that can be slipped onto the box of Snow and Ice Control (SNIC) trucks. After about 350 hours of engineering time and 800 hours of manufacturing, Fleet Services developed a prototype asphalt hot box that would slip into the back of the truck was delivered.
“By using the SNIC trucks, which are parked in the summer, we turned these units into multi-purpose trucks that can be used year-round,” said Majid Asefi, Fleet Operations Manager. “This saves The City a significant investment in purchasing the additional chassis that was previously required.”
The redesigned unit, which was fabricated in-house at the Fleet Fabrication and Welding shop, also allows the Roads crews to use the recycled asphalt pulled up from construction zones. After collecting the asphalt, recycling it is a four-step process:
1. Apply emulsion (a liquid solution) to the asphalt carrier
2. Apply emulsion to the asphalt
3. Load the asphalt carrier with material
4. Bake at ~ 350 °F for 8-12 hours
After these four simple steps, the asphalt is ready to reuse!
Crews can let the material bake during peak traffic periods in the afternoon, then get back out on the roads in the evening to start filling potholes. The baking process can occur without an operator while crews attend to other maintenance work, which makes the machines even more efficient. Crews can recycle up to four tonnes of asphalt each time the cycle runs, at a total cost of just $29 per tonne. For every tonne recycled, we save $141.
The first trial used asphalt from manhole work in the southwest, which was re-purposed for a pothole in Charleswood. With a successful trial under their belts, crews are looking to turn more trucks into multi-purpose pieces of equipment. If two trucks could each recycle three tonnes of asphalt each day, crews could re-use almost 100 tonnes of asphalt every month, saving around $14,000.
As the temperature cools down, crews may soon switch to snow and ice control. To prepare for next year’s summer road work, Fleet Services has refined the initial design and is currently building six additional units.
For more information, visit the City’s Roads Maintenance program page.