INVESTIGATION OF CREEP EFFECT ON MOISTURE WARPING AND STRESS DEVELOPMENT IN CONCRETE PAVEMENT SLABS

A major reason for the fatigue failure of concrete pavements is the coupling of curling and warping deformation and traffic loads. The moisture gradient and moisture warping would exist in concrete slabs for a relatively long time, which are inevitably affected by concrete creep. In this study, a test setup was designed to measure the flexural creep of concrete beams exposed to sealed and drying conditions and a calculation method of the flexural specific creep and creep coefficient was proposed. The calculated creep properties were then incorporated in finite element analysis to analyze the creep effect on warping deformation and stress generated in slabs when they are either bonded and unbonded with base. It is found that the flexural creep under drying condition is approximately 1.67 times that under sealed condition. Creep can reduce warping deformation and warping stress as well as the total stress when the traffic loads are considered together. The creep effect is significant in slabs bonded with the base, and reduces warping deformation and warping stress by 36% and 45%, respectively. The total stress caused by the coupling of the moisture gradient and the traffic loads applied at the slab corners is reduced by 34%. Therefore, it is important to take into account the creep effect when conducting deformation and stress analysis of concrete pavement slabs.