Damage Analysis Of Jointed Plain Concrete Pavements In Indiana Part I

Current design procedures for concrete pavements do not account for several factors that can influence their service life. In this work, these factors are investigated and the findings are integrated into a procedure for better predicting longterm performance of concrete pavements. To achieve this, sophisticated finite element techniques are employed and parametric studies are performed. The findings are then integrated into a nonlinear procedure for damage accumulation. In the development of the comprehensive 3D Finite Element (FE) model several issues are studied including the geometry of the model, mesh refinement, element selection, interaction between pavement components, and loading simulation. The developed model is then used in a number of parametric studies to investigate the effect of soil conditions, subbase and slab thickness, and slab length and stiffness on the developed stresses. Among other findings, it is established that for a given slab length, increasing the slab thickness beyond a certain limit is not justifiable. The developed FE model is also used to investigate the behavior of skewed concrete pavement slabs under several loading conditions. In particular, the crack patterns obtained from the FE analyses are compared to those observed in an actual skewed concrete pavement. It is found that the developed FE model is able to successfully predict the cause and orientation of the failure of this pavement section. An investigation of various existing fatigue equations is also carried out and a software tool is developed to perform both linear and nonlinear damage accumulation calculations. A case study of an pavement section on Interstate 70, which has failed prematurely, is created using the previously developed finite element techniques. The resulting stresses from the finite element analyses under various loading conditions are then used in the damage analysis of the pavement section. It is predicted that, irrespective of how the damage is accumulated, the pavement should have failed at an early age. Nonlinear damage accumulation predicted that the failure would occur at an earlier age than linear damage accumulation, which is consistent with the observed behavior of the pavement section.