Theory of crack spacing in concrete pavements

A simple analytical model is developed to predict the average crack spacing and crack depth in highway pavements due to thermal loading. The pavement is modeled as a beam on a Winkler elastic foundation. The effect of cracks on the pavement is considered on the basis of compliance functions. A simple method is introduced to describe the behavior of the pavement material according to nonlinear fracture mechanics. It is shown that the material length in the fracture model should be defined by the total fracture energy, rather than the effective fracture energy. The effect of nonlinearity in the distribution of thermal stress across the pavement depth is also analyzed. The foundation of the pavement is found to have little importance. The theoretical predictions are shown to compare well with field observations on asphalt pavements.