Using Precast Concrete Inlay Panels for Rut Repair on High Volume Flexible Pavements

The Ministry of Transportation of Ontario (MTO) in Canada has identified that several of their high traffic-volume flexible pavements are experiencing rutting failure early in their design lives. The pavement structures in the areas of premature failure consist of layers of hot mix asphalt (HMA) over granular base/subbase materials and experience significant truck traffic. The MTO has decided to investigate an innovative rapid pavement rehabilitation technique which distributes traffic loads over a larger area in order to avoid future rutting failure. Concrete has been identified as an ideal material to avoid the previously mentioned performance issues. However, conventional cast-in-place concrete is impracticable due to the high traffic volumes on these roads and corresponding short construction windows. Normal and fast-track concrete repairs require periods of strength gain which would extend beyond the 8-hour overnight construction window required by the MTO on these heavily trafficked highways. Precast concrete inlay panels provide a practical solution to this challenging rehabilitation problem. A 100-m test section is planned for construction during the 2016 construction season in Ontario. A new rehabilitation strategy will be employed in which existing HMA is milled to a design depth and precast concrete panels are placed within the 8-hour overnight work window, such that daytime traffic is not impacted. The test section will be instrumented to acquire stress and moisture data in addition to traditional surface testing methods. This paper will summarize the construction process and all data which has been gathered and analyzed up to the time of the 2016 conference. Both foreseen and unforeseen difficulties in the construction process and their solutions will be discussed in order to gain insight into the feasibility of this novel rehabilitation strategy.