OPAC (Ontario Pavement Analysis of Costs) is a computerized system that compares the performance and cost of hundreds of design alternatives for flexible pavements within just a few hours. Using the system, pavement design engineers can select the most effective pavement design that has the least cost. OPAC predicts the life of a pavement. The deterioration in Riding Comfort Index (RCI) has been made a function of repeated traffic loading and annual cyclic environmental changes. The deteriorations caused by the two factors have been respectively modelled using data from the AASHTO (Illinois) Road Test and Brampton (Ontario) Road Test. Subgrade surface deflection under a standard wheel load has been used as a predictor of future behavior of a pavement. Successful thickness designs in the province were analysed using Elastic Layer Theory and several iterations of such analyses resulted in a set of modulus values which were thereafter assigned to various paving materials and six different categories of subgrades in the province. Through AASHTO Road Test data, an excellent correlation between subgrade surface deflection, traffic, and pavement performance has been developed to allow calculation of that component of pavement deterioration which is caused by traffic. The other component, caused by environment, has been modelled from the Brampton Road Test data. It is based on the difference in deterioration predicted due to traffic, as previously indicated, and actual measured deterioration of Brampton Road Test sections over a period of eight years. The two submodels for pavement deterioration are combined to predict the performance of any pavement section. OPAC predicts pavement costs throughout the life of a pavement.

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 841-854

Subject/Index Terms

Filing Info

  • Accession Number: 00170252
  • Record Type: Publication
  • Report/Paper Numbers: Proceeding
  • Files: TRIS
  • Created Date: Mar 29 1978 12:00AM