Analysis of Concrete Pavements by Rectangular Thick-Plate Model

Abstract

Westergaard solutions for maximum bending stress and deflection are obtained by assuming infinite pavement slab width and length, without considering possible thick-plate behavior of slab under loading. This paper studies the effects of these two factors on Westergaard solutions by comparing with thick-plate solutions for rectangular slabs. The assumption of infinite slab is found to be valid if the slab length is more than four times the radius of relative stiffness. Because of thick-plate action, though, not all solutions for slab responses converge to Westergaard values when slab sizes are large. For large slabs where the effect of slab dimensions is negligible, the difference of thick-plate solutions and Westergaard solutions for maximum bending stress are less than 15 percent for square slabs, and less than 20 percent for 3.66 m wide rectangular slabs. The values of maximum deflection derived from the two solutions show good agreement in the case of square slabs. For 3.66 m rectangular slabs, though, Westergaard solutions underestimate maximum deflection by 10 to 70 percent, depending on the value of radius of relative stiffness of the slab-on-grade system.