Abstract: The upward lift due to moisture gradient, which couples with joint loading, can cause early-age transverse cracking in jointed concrete pavements. Though the importance of moisture effect on concrete pavement has been widely recognized, usually moisture deformations and stresses were ignored in pavement analysis because of a lack of comprehensive understanding on moisture transport properties and the difficulties in characterizing their magnitudes. This paper discusses three moisture transport processes and their effects on internal relative humidity distributions which are thought to be the major factors affecting concrete pavement deformations and stresses. In this study, the mechanism of moisture warping in concrete pavement is revealed and a new methodology is proposed for characterizing moisture-related deformations in slab on ground based on a relationship of shrinkage versus relative pore humidity for concrete. The proposed methodology provides for a simple post-processing of moisture-related deformations and stresses in concrete pavement.