PREDICTED AND FIELD BEHAVIOUR OF AN ASPHALT TEST PAVEMENT --14TH ARRB CONFERENCE, 28 AUGUST - 2 SEPTEMBER, 1988, CANBERRA, ACT, AUSTRALIA; PROC. PARTS 1 - 8

In this paper the mechano lattice method of analysis is used to predict the performance of a relatively thin (100 mm) asphalt pavement placed over a weak subgrade having soaked CBR values in the range of 2-4 per cent. The predictions were made up until the end of the service life of the pavement after the estimated passage of the equivalent of 680,000 standard axles. The mechano lattice method was used because it takes into account the elasto plastic behaviour of the materials and simulates the passage of a rolling wheel. Predictions were made for the pavement at a temperature of 10 degrees celsius during its service life, 22 degrees celsius (near the w-mmat) and 40 degrees celsius. It was found that the predicted rut depth at 22 degrees celsius (10.7 mm) was close to the field value (9-12 mm) and that there was very little increase predicted if the service life was at a temperature of 40 degrees celsius (11.7 mm). The fatigue life was considerably underestimated although the method did successfully predict that longitudinal cracking would occur before transverse cracking. It was also predicted cracking would initiate at the bottom and not the top of the asphalt layers. The authors discuss how the fatigue life prediction could be improved by refinements to the model (a). For the covering record of the conference, see IRRD no 808936.