Prediction of Premature Cracking in Jointed Plain Concrete Pavements

Abstract

This paper presents a mechanistic analysis of the occurrence and extent of premature cracking in jointed plain concrete pavements (JPCPs) by modeling (1) vehicle–pavement interaction, (2) foundation voiding, and (3) environmental conditions affecting pavement cracking. A finite-element (FE) pavement response model was developed to calculate the responses (stress and curling profile) of JPCPs. To characterize the loss of foundation support due to voids below concrete slabs, the nonlinear foundation model was linearized by spatially mapping the nonuniform modulus of subgrade reaction under the slabs. The linearized foundation model was incorporated into the pavement response model to evaluate the total flexural stress history in the slabs. A so-called quarter-vehicle model was used to calculate the dynamic tire force variation in response to a periodic surface profile caused by slab curl. Influence functions were used to combine the static elastic response of concrete slabs with the dynamic tire forces to determine the dynamic variations of surface stress and to predict fatigue cracking at various positions along the road. The initiation and propagation of premature longitudinal, transverse, and corner cracks was predicted using linear elastic fracture mechanics (LEFM). The study showed that dynamic tire forces have a significant effect on the location and magnitude of fatigue cracking in jointed concrete slabs. Cracking rates and the locations of peak stresses are affected by the combination of temperature gradient, vehicle characteristics and speed, slab properties, and foundation support. In addition, the occurrence of voids along the outer edge of pavements can lead to premature top-down longitudinal cracking and bottom-up transverse cracking.