Kivi, Aleks; Tighe, Susan L; Fung, Rico; Grajek, Jozef.
Asphalt pavements; Case studies; Concrete pavements; Deterioration; Pavement performance; Portland cement concrete; Rehabilitation (Maintenance); Urban highways
Municipal agencies are challenged to provide high quality pavements, despite aging infrastructure and shrinking budgets. However, the nature of heavy urban traffic can be extremely damaging to asphalt pavements. Despite the preference of many municipalities for hot mix asphalt as a paving material, Portland cement concrete has numerous technical and economic benefits that make it an excellent choice for rehabilitating urban pavements. This paper focuses on urban pavement maintenance and rehabilitation considerations, and presents a case study of two types of rehabilitation strategies using concrete pavement materials. The performance of these pavements during their first ten years of service is discussed and the future maintenance and rehabilitation needs of these sections are considered, based on current performance trends. The City of Toronto was observing the rapid deterioration of the pavements at an urban intersection with high volumes of transit bus traffic. In order to mitigate the frequent rutting and shoving problems that were recurring despite regular maintenance and rehabilitation interventions, the City elected to rehabilitate the troublesome intersection using Portland cement concrete materials. As part of this project, the city constructed its first unbonded concrete overlay and reconstructed an adjacent area as with conventional Jointed Plain Concrete Pavement inlay. The results of this case study show that concrete overlays and inlays are excellent rehabilitation options for urban pavements subjected to high volumes of heavy traffic. Both the unbonded overlay and Jointed Plain Concrete Pavement sections have demonstrated excellent performance to date. The pavements are in very good condition visually, ride quality remains excellent and the recurrence of the regular rutting and shoving problems that were being observed prior to rehabilitation has been mitigated. Significant remaining life is expected from the concrete pavement sections at Bloor and Aukland. Frequent maintenance interventions have no longer been required.