Quick fix or longer lasting? Sudbury looks at options for next pothole repair equipment purchase

Sudbury — For its next major road repair purchase, Greater Sudbury is trying to strike a balance between equipment that repairs potholes more quickly, and slower ones that provides a longer-term fix.

At a recent operations committee meeting, project manager Miranda Edwards outlined the different equipment needed for repairing rutted roads, depending on the time of year and circumstances. Costs for each range from $250,000 to $400,000.

The quickest and most widely used technique in Sudbury is known as 'throw and roll,' in which the pothole is quickly cleared of debris, filled with a mix of hot, cold and warm asphalt and flattened by a roller.

All-weather repair

"This approach is used regardless of the weather and is considered an efficient method of repair due to how quickly it can be completed," Edwards said in her report. "Because of this, it is the most commonly used repair method during pothole repair campaigns or where high productivity is required due to a high volume of potholes."

The second most popular technique is known as detailed patching, which is usually used in warm, dry weather. A pothole or even a larger section of the roadway can replaced, but it is more labour intensive and time consuming. When large sections are replaced, the repairs can extend the life of a road by three to five years. Currently, Sudbury has five, two-tonne hot boxes that are towed by a truck.

"Warm mix asphalt is hauled in a heated truck box from southern Ontario for these repairs," Edwards said. "This type of repair takes more time to complete than the throw and roll technique, but provides greater performance because of the repair technique."

Automated patcher

Each technique requires different equipment. One option the city is considering is buying an automated pothole repair unit. Working from a single truck, repairs can be done by one person who need not leave the vehicle. A second person is required to control traffic.

"This equipment can dispense either hot or cold mix asphalt that is maintained at the desired temperature and repairs potholes typical to the throw and roll technique," Edwards said. "To complete detailed patching with this equipment, a separate municipal tractor equipped with a grinder would be required."

Another technique, spray patching, also only requires a two-person crew. They can be either trailer mounted, requiring a separate truck to supply and load aggregate, or self-propelled with aggregate hopper. Rear-mounted boom systems are also available and are operated and controlled from the ground.

Finally, infrared patchers come in different sizes and configurations to fit different size and shaped repairs. Larger infrared road repair units are mounted on a truck and smaller infrared units, may be loaded and transported to a location by trailer.

Advantages/drawbacks

Each technique has advantages and drawbacks. Hotboxes require crews of three to four people and take longer to complete, but the repairs last longer. Spray patchers have smaller crews, but can't operate in wet conditions. Automated units can work quickly, but the repairs are temporary.

Edwards said finding a balance, and ensuring they have the right equipment for the right conditions, is key.

"When carrying out a pavement maintenance program, it is important to utilize the right techniques at the appropriate time to maintain the serviceability of a road network," she said. "All of the techniques and equipment described in this report are viable options to consider when repairing potholes. When evaluating the decision to purchase pothole repair equipment, it is important to evaluate the benefit the equipment provides compared to the cost to purchase and maintain it."

The operations committee approved a plan to have staff evaluate the equipment and come back with a report recommending the best option for the city.

Read the full report here.