RPAS: An Enhanced Finite Element Code For The Mechanistic Analysis Of Rigid Pavements

Significant amount of research has been conducted to improve the design of rigid pavements through the development of mechanistic analysis tools capable of accurately modeling the performance of such pavements. The use of the finite element (FE) method as a comprehensive tool for modeling the responses of rigid pavements has been limited in the past because of the complexity of calculations in modeling nonlinear behaviors, which are difficult to describe mathematically and computationally. Researchers from The University of Texas at El Paso developed NYSLAB, an FE modeling tool, for the analysis of rigid pavements subjected to traffic and environmental loading conditions. Through a series of software improvements and verification studies, the tool has been validated for the analysis of jointed concrete pavements (JCP). The objective of this Dissertation is to present an enhanced version of NYSLAB, renamed RPAS, to include the analysis of continuously reinforced concrete pavements (CRCP). To improve on the existing FE models, a 3-D foundation model and a nonlinear contact model were incorporated in RPAS. A 3-D CRCP model was developed that includes the complex bond-slip interaction between reinforcing steel and concrete and was implemented into the main code as a separate component for a detailed analysis of a pavement area of interest. The incorporated models were verified and evaluated through a series of case studies. Based on the results, RPAS was demonstrated to be capable of modeling both JCP and CRCP pavements adequately. Since the addition of the 3-D foundation model, RPAS is currently the only rigid pavement analysis system that is capable of identifying critical (maximum) responses at any depth of the foundation, including the subgrade layer. Furthermore, RPAS is currently the only tool that obtains the responses from a large-scale CRCP model and then focuses on an area of interest to determine detailed responses of the reinforcing steel and concrete as well as the interaction between them