Effect of Dowel Looseness on Response of Jointed Concrete Pavements

This paper examines the effect of dowel looseness on the structural response of jointed concrete pavements. A technique for modeling dowels in 3D finite-element analyses of rigid pavement systems is presented that relies on an embedded formulation of a quadratic beam element. This embedded element permits the efficient modeling of dowel looseness using a nodal contact approach and allows the dowels to be exactly located irrespective of the slab mesh lines. The embedded bending element is extended to include a general bond-slip law, and the practical case of a Winkler foundation sandwiched between the dowel and slab is implemented. The results of parametric studies examining the significance of dowel looseness on the response of rigid jointed pavements to both axle and combined axle and thermal loadings are presented. These studies indicate that significant increases in both slab and soil stresses can be expected due to small gaps (≤0.24 mm) between the dowels and the slabs. The importance of explicitly modeling nonlinear load transfer arising from dowel looseness is also examined, and it is shown that equivalent, back-calculated dowel support moduli should be used with caution when dowel looseness exists.