Full-depth asphalt concrete pavements are generally designed to resist fatigue and rutting when subjected to repeated traffic loads.Of particular importance in this case is whether such pavements will exhibit increased accumulation of plastic strains under long-term, repeated loading conditions that will eventually lead to incremental collapse or whether the accumulation of plastic strains will ceaseand a shakedown condition is reached. In this paper, the shakedown theory is used in the analysis of full-depth asphalt concrete pavements overlying clay subgrade. The proposed numerical algorithm incorporates the stress-dependent resilient behavior of the subgrade. The influences of stiffness and strength of the subgrade, and thickness and temperature of the asphalt concrete on shakedown behavior are illustrated. Results are used to develop shakedown-limiting criteria in terms of vertical stresses and strains acting on top of the subgrade layer. Moreover, coparisons among shakedown, fatigue, and rutting predictions are presented. This paper appears in transportation research record no. 1227, Rigid and flexible pavement design and analysis: unbound granular materials, tire pressures, backcalculation, and design methods.
Abstract