Calculation method of moisture warping stress for cement concrete pavement slab

In order to analyze the impact of moisture gradient on mechanical properties of cement concrete pavement, the calculation formulas of moisture warping stress for nonhomogeneous infinite pavement slabs subjected to free-rein constrain, axial deformation constraint, bending deformation constraint, bending-axial deformation constraint were derived by using the basic analysis method of elasticity mechanics.The formula of equivalent temperature gradient based on the moisture warping stress was derived by using the equivalent principle of moment.Based on continuously reinforced concrete pavement(CRCP), the stresses and crack widths of concrete slab and steel stresses were computed by using the finite element method based on cement stabilized base, stable aggregate base, asphalt concrete base, asphalt stabilized base, limestone soil base and natural soil base.Research result shows that the magnitude of moisture warping stress depends on the relative humidity distribution; the surface stress at slab middle increaseswith the increase of base stiffness, when the stiffness of base increases from 0.08MPa·mm^-1 to6.28 MPa·mm^-1, the surface stress increases from 4.1 MPa to 6.3 MPa; the type of base hardly has influence on the stress of steel; the horizontal displacement of crack end gradually increases from 0.0 mm to 2.9 mm from slab bottom to surface.