Investigation of an alternative gravel roads rejuvenation method
Aggregate surfaced roads become coarser and coarser after a few years of service due to an inherent problem--dust emission. Fine aggregate in the surfacing material is kicked up by passing traffic and blown away as dust. One of the alternative rejuvenation methods is to replenish the missing fines to restore the gradation and plasticity of the in-situ material. Savings in the material and cost could, in return, benefit the environment and financial condition of the jurisdiction. Control and experimental test sections were established in three counties in Minnesota. Performance of test sections were assessed, which included monitoring of cross section profile change, gravel loss and loose aggregate measurements, gravel road condition rating, International Roughness Index, field observation, etc. Experimental sections in Jackson County did not perform satisfactory. However, one of the test sections in Beltrami Counties performed favorably well. A five-year cycle benefit-cost analysis revealed that a 20 percent of cost savings is also achievable in that particular sections. Another trial performed in Olmsted County is also included in this paper. The trial tested if the modified Class 5 Limestone Aggregate is appropriate for gravel road surfacing.