ANALYSIS OF CRC PAVEMENT UNDER MOISTURE, TEMPERATURE, AND CREEP EFFECTS

Abstract

A numerical procedure is presented for studying the effects of steel reinforcement and environmental parameters on the early­ aged behavior of continuously reinforced concrete (CRC) pavements. The numerical procedure consists of two stages. The first stage predicts shrinkage strains developed due to moisture loss in the concrete pavement. It uses the semi-discrete method of nonlinear finite element analysis to predict the moisture distribution in CRC pavement as a function of time. This model is verified with published theoretical and experimental results. An existing finite element model (originally developed for the analysis of moisture distribution in subgrade materials) is modified and adapted for moisture distribution analysis in concrete pavements. Both shrinkage and thermal strains are determined in two stages of analysis. Shrinkage strains (predicted in the first stage) and the thermal strains (predicted in second stage) imposed due to variations in ambient temperature are used as input to the stress analysis. The second stage predicts stress distribution taking into account concrete creep in the pavement after initial development of the crack pattern. The CRC pavement is represented in the finite element analysis with two-dimensional plane strain elements. Bond slip is modeled at the interface of concrete and steel. Analysis of the internal restraint is performed to determine subsequent concrete pavement stresses due to environmental effects. A finite element code was developed specifically for the prediction of the resultant stresses in the concrete pavement.