Effects of truck tire type and tire-pavement interaction on top-down cracking and instability rutting

Top-down cracking (TDC) and instability rutting are two of the main failures in the flexible pavements across the world. Earlier studies have shown that these are near-surface distresses that are greatly affected by tire-pavement interaction. The overall objective of this study was to develop and validate 2-D and 3-D tire models as well as tire-pavement interaction models based on finite element code ADINA and use them to investigate the effects of tire type, tire-pavement interaction and pavement cross-section profiles on top-down cracking and instability rutting performance. A range of radial truck tire types including dual, super single and new generation wide-base tires were modeled based on tire geometry and structure information provided by the tire manufacturers. Tire models were calibrated based on load-deflection data and verified by comparing measured and predicted contact stresses. The results indicated that the tire models developed can accurately capture both vertical and horizontal contact stress characteristics and thus can be used for further evaluation purposes.;In this study, it was found that there is a significant difference in contact stress distributions among different tire types based on finite element simulation. Accordingly, near-surface stress states in terms of principal tensile stress and maximum shear stress were quite different among the different tires. Analysis results indicated that super single wide-base tire might produce greater damage to the pavement in terms of both top-down cracking and instability rutting than either dual tires or new generation wide-base tire. Analysis results also indicated that pavement cross-sectional profiles with rutting or cross slopes increased the propensity for top-down cracking and severity of instability rutting.;Parametric studies showed that pavement structure had relatively little effect on the stress states affecting top-down cracking. However, weak base or subgrade increased the propensity for instability rutting. Also, both overloads and under-inflation would likely increase the initiation of top-down cracking and instability rutting. Increasing the flexibility of tire sidewall or decreasing the rigidity of the tire tread may reduce the propensity for top-down cracking and instability rutting. Future studies, including dynamic effects of vehicle and degree of wear on the tire-pavement interaction are needed. (Full text of this dissertation may be available via the University of Florida Libraries web site. Please check http://www.uflib.ufl.edu/etd.html)...