83rd St. SW, also known as Heinrich Road in Bowman County, N.D., was in need of repair. The 4.2-mile section of roadway is populated by several farmsteads and ranches. The route joins U.S. highways 67 and 85, and carries approximately 50 to 100 vehicles a day.
“The chip seal on this road had become soft and broken up in many areas,” said Neil Hofland, highway superintendent for the county. “The roadway was narrow with a 24 ft wide top and the in-slopes were too steep. This presented a hazard to the community. The annual maintenance cost was $17,000, which consisted of cold-mix repairs and Dura patching. In 2009, we reconstructed the road by grinding up the existing material, removing the salvage, widening the surface to 32 ft, and re-laying the salvage. We also added 4 in. of ND Class 13 gravel per mile.”
“We selected the second option primarily because in past years the road would eventually become soft and we wanted to provide a hard, smooth driving surface for many years to come,” said Hofland.
In 2010, the county added 4 in. of ND Class 13 gravel per mile and incorporated the base stabilizer at the recommended rate of .005 gal per sq yd per inch of depth. The stabilizer was added to a water truck and the stabilizer/water mix was sprayed and mixed into the 4 in. of material and compacted.
Hofland continued, “To apply the double chip seal the stabilized surface was shot with a light coating of water, then we added the emulsion oil (Pass CR) at a rate of .5 gal per sq yd and no prime. We immediately applied ¾-in. chips at a rate of 34 lb per sq yd. This was compacted and let set for nine days. “After nine days we applied a HFMS-2 at a rate of .5 gal per sq yd and added 17 lb of 3/8-in. chips per sq yd. We waited one day and then swept the loose chips and fogged the surface with CSS-1H. The fogging was applied with a 50% solution of water and CSS-1H at a rate of .1 gal per sq yd. The road was then closed to traffic for five hours.”
Hofland said the results have been outstanding. After a tough winter and a record snowfall, the road has shown minimal cracking, there have been no issues with the shoulders and no need for patchwork.