Development of a longitudinal cracking fatigue damage model for jointed plain concrete pavements using the principles of similarity

Abstract

Mechanistic-empirical (M-E) pavement design computes stresses induced in a concrete slab due to applied traffic and environmental loads, and correlates these stresses to distress levels using empirical correlations. Currently, the Mechanistic-Empirical Pavement Design Guide (MEPDG) is one of the most advanced and prevalent methods of M-E pavement design. While the MEPDG predicts transverse cracking, longitudinal cracking is not predicted, even though longitudinal cracking is commonly observed in jointed plain concrete pavements (JPCPs). In this research, an MEPDG compatible model was developed to predict longitudinal cracking fatigue damage in JPCPs. This modeled adapts the framework of the MEPDG specifically for longitudinal cracking. In order to develop an M-E longitudinal cracking fatigue damage model, it is necessary to compute stresses at the critical location for longitudinal cracking due to the various traffic and environmental loads to which a pavement could be exposed. The principles of similarity were used to map the original problem into similar space, which drastically reduces the complexity of the problem without introducing any error. To avoid the computational inefficiency associated with embedding a finite element program within the program, neural networks are used for rapid stress solutions. Stresses determined in similar space are converted back into real space for damage computation. Modifications were made to the MEPDG fatigue damage computation process to eliminate simplifying assumptions and to make the procedure applicable to longitudinal cracking. A study was also conducted to determine characteristics of pavement susceptible to longitudinal cracking based on various parameters. This study made use of the principles of similarity to examine almost all pavements which could be considered in M-E design. By identifying the characteristics of pavements susceptible to longitudinal cracking, engineers can identify pavements for which longitudinal cracking analysis should be conducted. The model and design procedure developed in this research provides the tools needed to conduct such an analysis.