METHODOLOGY FOR PREDICTING ASPHALT CONCRETE OVERLAY LIFE AGAINST REFLECTION CRACKING. SIXTH INTERNATIONAL CONFERENCE, STRUCTURAL DESIGN OF ASPHALT PAVEMENTS, VOLUME I, PROCEEDINGS, UNIVERSITY OF MICHIGAN, JULY 13-17, 1987, ANN ARBOR, MICHIGAN

This paper describes a new design methodology for the prediction of the reflection cracking life of asphalt concrete overlays. A mechanistic empirical approach is used in developing the present design procedure. The variables used and the form of the design equation were chosen based upon a mechanistic model which represents the actual process of pavement failure. An approach which makes use of principles of fracture mechanics and beam-on-elastic foundation theory is used in developing the mechanistic model. The mechanistically computed pavement responses are then regressed against observed distress on overlays to obtain the final design equations. The data collected on a large number of pavement sections located at various parts of the State of Texas and stored in the computerized data base at Texas Transportation Institute were available for the use of this research study. From these, 40 flexible pavement sections with bituminous concrete overlays were selected for the analysis. From the correlations obtained in the regression analysis, it is evident that this methodology may be employed successfully in the design of asphalt overlays. In the conclusion of the paper, the need to perform similar analysis on data collected from regions of varying climatic conditions is emphasized.