In the extended winter of 2013-2014, Wright County’s road maintenance crew in central Minnesota, needed all the help they could get to keep their rural routes in good condition. Cold weather keeps the asphalt plants closed in this part of the country, so waiting for a spring that never seemed to come was not a viable option for hot-mix patching.
In addition to potholes, many county roads experience washouts and edge breaks that really don’t benefit from a hot-mix fix. Exacerbating the situation is the heavy commuter traffic on County Road 16 SE from Delano to SH 7 which leads to the Twin Cities. And recently a sanitation firm moved into the county with heavy truck traffic that further strains the two-lane rural roads. Bruce Bersie, patching crew foreman for the county and former MnDOT employee, simply stated, “We used to hot-mix patch before, but it was always too little too late to keep up with the maintenance.” The company searched for another solution and found it less than 50 miles from their equipment yard in Buffalo, Minn.
“We tried a spray-injection patcher manufactured by Cimline and found it provided a more permanent fix and reduced our costs,” Bersie noted. “The DuraPatcher also enabled our crews to build up broken pavement edges and pothole patch year round.”
The county also realized better utilization of their personnel because what was once a seven-man hot-mix patching crew became a four-man crew when they purchased their own machine two years ago. The county has approximately 500 miles of roads to maintain.
“Our patching work used to be a once-a-year proposition. Now with the year-round capabilities of the spray-injection patcher, we can dispatch a crew whenever there is a need. With the freeze-thaw effect in Minnesota, roads come apart at any time,” Bersie said.
The spray-injection method provides a permanent repair by spraying a mixture of emulsion-coated aggregate with sufficient force to compact the mixture as it is applied in layers.
Keeping up with road repairs has been easier with the speed of the spray-injection method. The four-man crew consists of two persons on traffic control, a hose man and the truck driver.
“We were able to patch 6 miles of County 16 in half a day—a patch only takes minutes,” according to Bersie. “Those roads like County 16 that are nearing their overlay date really need to be held together for the last year or so. This spray-injection method has helped us preserve the pavement to acceptable levels before replacement.”