3D Finite Element Analysis of Temperature‐Induced Stresses in Dowel Jointed Concrete Pavements

A detailed 3D finite element (3DFE) model is developed to investigate the applicability of Westergaard's curling stress equations to doweled jointed concrete pavements. The model does not rely on any of Westergaard's assumptions and is capable of handling nonlinear and/or time‐dependent temperature profiles. However, only linear gradient is applied to facilitate the comparison with Westergaard's results. The transverse stress calculated using Westergaard's formula was found to be within 10% of that computed using 3DFE. Westergaard's longitudinal stress equation required a correction. The 3DFE results confirm Westergaard's finding that the slab curling stresses are independent of slab length. Thus, curling stress does not explain the field‐observed dependency of mid‐slab cracking on the slab length. Through the examination of the mechanism of dowel‐concrete interaction, it is shown that uniform temperature changes play the major role in mid‐slab transverse cracking of relatively long slabs. Due to built‐in slab curling as well as temperature or moisture curling, the dowel bars bend restricting the slab from free contraction due to uniform temperature drop. This gives rise to a large component of stress that has not been considered in previous investigations. Application of a combined temperature gradient and uniform temperature drop to slabs of different lengths revealed the dependency of mid‐slab transverse cracking on slab length.