Bowman County, N.D., keeps road from going soft

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.”

In 2010, the county entertained three options to complete this project. The first option was to leave it as a gravel road. The second was to stabilize the base with Team Laboratory Chemical Corp.’s Base One Aggregate Base Stabilizer and a double chip seal. The third option was to apply an overlay, but this was eliminated due to cost.

“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.