Repairing high volume HMA highways with precast concrete inlay panels

The pavements which make up Canada's high volume highways are subjected to some of the most demanding conditions in the world. They must structurally be capable of supporting significant traffic loading, which can exceed an average of 30,000 trucks per day. They must be capable of supporting these loads throughout the wide variety of environmental conditions to which they are exposed, ranging from hot summers to cold winters. In order to achieve service lives which do not necessitate frequent maintenance and repair activities, these pavement structures are required to be very resilient. A complication to constructing the resilient pavement structures is that construction activities on high volume highways are generally limited to over-night construction windows that are six to eight hours long. At the end of this construction window, full traffic must typically be reinstated. Ontario's Ministry of Transportation (MTO) has a number of high volume highways which have been reaching the end of their service lives prematurely due to deep-seated pavement rutting issues. These highways have previously been rehabilitated using a mill and replace strategy. In response to this issue and the restricted construction windows for rehabilitation operations, a new rehabilitation strategy has been developed for rehabilitating high volume hot mix asphalt (HMA) highways. This strategy is the use of Precast Concrete Inlay Panels (PCIPs) which are placed within a partially milled HMA pavement structure. A trial section of the PCIP strategy has been designed and proposed to the MTO for implementation and this paper outlines the development of the rehabilitation strategy, with specific focus on details produced to address to the unique nature of this rehabilitation strategy. These details include panel support conditions, built in design details, and construction specifications that address various constructability and performance concerns.