Long Term Evaluation of Unbonded Concrete Overlay Technology: A Municipal Case Study

Abstract

Portland cement concrete (PCC) overlays are growing in popularity as a costeffective means of pavement preservation or rehabilitation. When properly designed and constructed, concrete overlays are a durable and cost-effective solution. This technology can be an excellent choice for municipal pavements, which are often subjected to heavy, slow moving vehicles. This paper presents an overview of design and construction considerations for unbonded concrete overlays, with an emphasis on details relating to the use of this technology in municipal applications. The included case study presents a synopsis of the City of Toronto's experience with the design and construction of its first unbonded concrete overlay project on Bloor Street. The performance of this trial section and lessons learned from the first twelve years of service are discussed.