MECHANISTIC-EMPIRICAL RIGID PAVEMENT DESIGN FOR NEW YORK STATE

In 1993 New York published a new "Thickness Design Manual for New and Reconstructed Pavements" based on the 1986 AASHTO design guide. The AASHTO equation for rigid pavement performance was calibrated with performance data for 225-mm rigid pavements in New York, and the calibrated equation was then used to design rigid pavements. Because New York does not have experience with thicknesses greater than 225 mm, the modified AASHTO equation could not be verified for thicker pavements. The development of a mechanistic-empirical (M-E) design procedure for verifying the designs presented in the new thickness manual is described. First, a nondimensional fatigue model was established on the basis of New York's past pavement performance, environmental conditions, and traffic loadings. The study was then extended to develop design curves for thicknesses of 225, 250, 275, 300, and 325 mm (5-m slab lengths for 225- to 275-mm thicknesses and 5.5-m slab lengths for 300- to 325-mm thicknesses). Finally, the M-E design curve was compared with the modified AASHTO equation. The results indicate that for thicknesses greater than 275 mm, AASHTO predicts up to 40% more equivalent single axle loads than the M-E approach.