Asphalt Mix Overlay Alternative for Low Volume Roads on the Local Transportation System

 

Many local governments are faced with low volume roads in need of repairs due to fatigue cracking.  Currently, there are relatively few known economical solutions from which to choose.  Options range from costly full-depth reclamation to chip sealing.  Some county engineers have tried other techniques to address this issue with varying degrees of success.  Some local agencies, such as Medina and Muskingum County, have used a cold-laid, motor paver mix followed by a chip seal surface.  While these counties have seen some positive results to this technique, the motor paver equipment is not widely available in Ohio and, for some local public agencies, can be expensive.  An option of a hot-mix that matches the performance of the motor paver mix that can be placed by hot mix paving contractors could make this treatment option more widely available to local agencies throughout Ohio.

 

While some transportation professionals believe the solution to this issue is in the application method, others question if the mix being used is more of a contributing factor.  ODOT has a supplemental specification (#823) that provides guidance for producing a light traffic asphalt mixture.  However, its direct application to local roads may not be appropriate.  Factors such as variations in traffic volume, traffic type and traffic patterns may influence the performance of this asphalt mixture resulting in the ODOT specification being over designed for the needs of the local road.  For example, SS 823 indicates that is it is designed for locations with less than 50 trucks per day.  In some rural Ohio counties, it is highly possible to have less than 50 trucks per year.  Given that high traffic volume for some county and township roads can be significantly less than what ODOT considers to be a low volume road, the impact weather has on the pavement can be more damaging to the road surface than the traffic.  Some county engineers have tried in-house developed mixes and have had varying degrees of success.

 

This research will be conducted in two phases. The goal of Phase 1 is to conduct an in depth practice analysis aimed at identifying existing research, best practices of Ohio's local government agencies, and opportunities from other states and based on state of practices, develop a laboratory testing protocol of mix design procedures.  Phase 2 will perform in-field evaluation of the mix design procedures identified in Phase 1 and is contingent upon the successful completion of Phase 1 and the written authorization of the ODOT Research Section.