APPLICATION OF EMPIRICAL AND MECHANISTIC-EMPIRICAL PAVEMENT DESIGN PROCEDURES TO MN/ROAD CONCRETE PAVEMENT TEST SECTIONS

Current pavement design procedures are based principally on empirical approaches. The current trend toward developing more mechanistic-empirical type pavement design methods led Minnesota to develop the Minnesota Road Research Project (Mn/ROAD), a long-term pavement testing facility. The project consists of 40 heavily instrumented test sections, 14 of which are jointed plain concrete (JPC) designs. Mn/ROAD researchers determine the predicted lives of the concrete test sections by applying design and as-built data to three currently accepted concrete pavement design methods: Minnesota Department of Transportation's rigid pavement design guidelines; American Association of State Highway and Transportation Officials (AASHTO) Guide for Design of Pavement Structures 1993; and the Portland Cement Association (PCA) Thickness Design for Concrete Highway and Street Pavements (1984). The analysis began with determining the applicable as-built parameter values for each respective design method. Applying the as-built parameters to the three methods resulted in widely varied predictions of pavement life. For the 1993 AASHTO design method, reliability levels of 50% and 95% were applied for comparison. An experimental procedure for converting PCA method fatigue and erosion results to AASHTO type CESALs (concrete pavement equivalent single axle loads) demonstrated unsuitability. Validation of the predictions presented will occur as the test cells reach their terminal serviceability.