Response of Jointed Rigid Pavements

Computer programs for calculating strain histories in rigid pavements under heavy truck traffic are described. A finite-element structural model, ILLI-SLAB, was modified to generate influence functions which are combined with the dynamic loads under the wheels of a truck to predict the strain time histories at points of interest in the pavement. Using experimental measurements of pavement response it is demonstrated that these programs are capable of predicting strains in a jointed rigid pavement when the dynamic loads generated by the truck and pavement properties are known. Variations in truck speed cause some variations in strain not replicated by the pavement model, which has no speed-dependent effects. Behaviour in the vicinity of a pavement crack is difficult to predict because of the unknown load transfer properties of the crack, the inconsistent load transfer performance from test to test, and an apparent but unexplained sensitivity of load transfer performance to the truck travel speed.