Enhanced finite element modeling of the thermo-mechanical responses of jointed PCC pavements under environmental and traffic loads

Mohammad Ali Zokaei Ashtiani, University of Texas at El Paso

Abstract

Jointed plain concrete pavements (JPCP) are the most commonly used type of rigid pavement systems and the accurate modeling of their thermo-mechanical responses is of primary importance in a mechanistic-empirical pavement design procedure. In JPCP, the temperature gradient and resulting slab shape play a crucial role in the magnitude of stresses and deflections caused by the superimposed traffic loads. Temperature gradients through the slab depth can produce thermal curling in slabs and can also produce slab expansion and contraction, which leads to the generation of frictional tractions between slabs and foundation. The prediction of these frictional tractions is complicated by the curling of the slabs that causes some portions of the slabs to lose contact with the foundation. From the initial development of pavement analysis software in the early 1970's, it was recognized that the finite element (FE) method was the most appropriate modeling tool, due to its potential ability to capture all the pavement response features. A series of software development efforts have culminated in the production of NYSLAB, a jointed pavement analysis tool that has the capability to predict the complete thermo-mechanical responses, due to the combined effect of environmental and vehicular loads. This dissertation presents a series of studies conducted toward developing an improved FE-based model to be used in the source code of NYSLAB. A complete review of characteristics and mechanistic behavior of components of JPCP is provided. Detailed mathematical models of pavement slabs, load transfer devices and foundation layers developed in NYSLAB are presented. In addition, the implementation of "interface elements" used to model the contact between pavement layers is included. These elements have the ability to capture the separation and sliding between pavement layers, due to thermal loads, and calculate the frictional traction at their interface. Finally, a series of parametric studies was carried out to determine that the governing equations that were used to idealize the behavior of JPCP in NYSLAB have been accurately selected and implemented in the FE model. The results presented in these studies highlight the capabilities of NYSLAB in modeling and considering the most important factors that affect the prediction of the stresses and strains produced in concrete slabs.^

Subject Area

Engineering, Civil|Engineering, Environmental

Recommended Citation

Zokaei Ashtiani, Mohammad Ali, "Enhanced finite element modeling of the thermo-mechanical responses of jointed PCC pavements under environmental and traffic loads" (2014). ETD Collection for University of Texas, El Paso. AAI3630478.
http://digitalcommons.utep.edu/dissertations/AAI3630478

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