The selection of the exposed concrete pavement for the mainline Highway 407 ETR - Express Toll Route involved a detailed evaluation of the subsoil and groundwater conditions for the full 69 km length of the facility, and consideration of traffic, environmental, maintenance and performance factors. Originally conceived as a design-build-own-operate-transfer project with the successful consortium to operate and maintain the facility for a 30 year period, this project offered the opportunity to consider pavement alternatives that were innovative for Ontario. A number of alternate pavement designs were developed using the American Association of State Highway and Transportation Officials (AASHTO), Portland Cement Association (PCA) and Asphalt Institute (AI) design procedures, with modifications incorporated to reflect the international state-of-the-technology for pavement design and construction. Life-cycle cost analyses were carried out for selected designs, considering both pavement initial cost and the cost of maintenance throughout its service life, to identify the most economic pavement alternative. The selected pavement structure for the highway through lanes and expressway-to-expressway ramps consists of 285 mm of plain, 35 MPa portland cement concrete, with tine-texturing for frictional properties, epoxy-coated dowels and random, non-skewed joints, and pre-formed neoprene joint seals, over 100 mm of asphalt-treated open graded drainage layer and 200 mm of crusher run limestone subbase. Maintenance activities such as retexturing to maintain frictional properties and joint resealing were also incorporated in the overall pavement design and life-cycle costing analyses. (A)
Samenvatting